marine propeller shaft power meter - fuse-network.com · marine propeller shaft power meter...

FUSE Demonstration DocumentApplication Experiment Number 25114

Marine Propeller Shaft PowerMeter

Microcontroller Technology Reduces Cost and Improves Performance

TTN: UGCS Ltd

Shaft Power Meter - Demonstrator Document

Application Experiment Abstract

Sea Technik Ltd is an independent UK based company specialising in the design,manufacture, installation and support of bespoke measurement, instrumentation and controlsystems for installation into ships. Sea Technik Ltd markets its products world-wide, andthese markets include Europe, the USA, and increasingly Japan and Korea. The company’scustomers are ship builders and major shipping fleet operators. The company employs 11employees and has sales of 0.6 M Euro.

The company’s products include a precision ship’s draft monitoring system, ship trim meter,a ship fuel optimiser and the Shaft Power Meter equipment.

The Shaft Power Meter product is installed on ships’ propeller shafts to allow the outputpropeller power to be monitored as part of the overall ship’s fuel usage optimisation controlsystem. The Shaft Power Meter is a high value system incorporated into 40% of medium tolarge sized ships during construction. The current product uses a PC and ‘bought in’ dataacquisition system components to perform this function.

Sales of Shaft Power Meter equipment is reliant upon cost competitiveness as the majority ofsales are to ship builders operating on fixed price build contracts. The objective of theapplication experiment was to significantly improve the cost competitiveness of thecompany’s product, and to introduce features that reduced the set up, calibration andmaintenance time and costs incurred by Sea Technik in these sales. The introduction ofmicrocontroller component technology was undertaken so as to realise reduce the complexityof the overall system design and simplify the precision mechanical assembly of parts of thesystem, leading to reduced cost and time required for the manufacturing process. In additionsimplified setting up and calibration processes to reduce commissioning costs, and improveddiagnostic facilities to reduce maintenance costs were delivered.

The improved functionality of the improved Shaft Power Meter product includes.

• Replacing the PC and ‘bought in’ data acquisition system components

• Simplifying the product’s calibration and set-up procedures.

• Providing self checking and diagnostic facilities.

• Reducing the circuit board size and therefore, achieving significant cost reductionsin mounting cost.

• Improving product reliability by the incorporation of additional measurement

• redundancy.

• Improving the flexibility of the product thereby allowing the company to tailor the ShaftPower Meter system to meet specific customer requirements, and thus improving theproduct’s sales potential.

The application experiment was completed on schedule in the planned duration of 10 months.

Through the utilisation of embedded micro-controller technology, substantial benefits havebeen realised through a simplified design, reduced costs, improved reliability and improvedsystem performance. These benefits will enable Sea Technik Ltd to extend marketpenetration, building on a solid reputation in the Power Measurement market. In addition, thecompany has developed improved knowledge and capabilities in implementing micro-controller technologies, and the potential to use the technology to develop a wider range ofproducts targeted at their market sector with the consequential improvement in sales andemployment prospects for the company.


The total cost of development to the prototype stage was 48 K Euro. The industrialisationcosts were an additional 15K Euro. Based on projected sales improvements the paybackperiod for the prototype development will be 13 months. The Return On Investment (ROI) forthe improved product is estimated to be 410% over the product’s 4-year lifecycle.

The company’s experiences in utilising the flexibility of micro-controller devices to completethe project on schedule will be of particular interest to those companies who trade in similarmarket places, and will include ship yards, ship operators, marine research establishmentsand associated equipment manufacturers. The targeted industrial sectors include generalmechanical engineering (Prodcom Code 2852), general purpose machinery (Prodcom Code2924), building and repairing of ships (Prodcom Code 3511), and electrical equipment forengines and ships (Prodcom Code 3161).

Keywords and AE Signature:

Keywords:Shaft power meter meteringFuel SavingTorque measurementPropeller ShaftMarine applicationsMonitoring equipmentSpeed measurementMarine equipmentTurbine power measurementsMicrocontroller

Signature: 2 0192 550 0410 1 3320 1 33 UK


1 Company name and address

Sea Technik Ltd 15 Glynne Way Hawarden Flintshire CH5 3NS United Kingdom Tel: +44 (0) 1244 535787 Fax: +44 (0) 1244 538908

2 Company size The number of personnel employed by Sea Technik Ltd Systems is 11. The company’semployees are involved in the following disciplines : Manufacturing 2 Sales / Marketing 2 Development: 3 Administrative 1 Accounts 1 Technical data preparation 2 The company turnover is approximately 0.6 MECU. The company’s microelectronics experience was related to the development of basic,discrete analogue and simple digital interface circuitry only. One engineer and twoengineering technicians were involved in this role.

3 Company business description

Sea Technik Ltd Systems provides systems design solutions for the marine and alliedmarket, and as such has extensive experience in this field. The company has extensivemarket knowledge gained over many years, and a strong background in marine engineering.

The company’s products include:

1. Shaft Torque and Power Meters, for the range 0 - 75 MW

2. Precision Draft Meters, for accurate determination of the draft drawn by a vessel.

3. Ship Performance Monitoring Equipment, generally for logging parameters relevant tooptimising fuel use, offering savings measured in tons.

4. Emergency Shut Down equipment, a fibre optic link between Liquefied Natural Gas (LNG)tankers and the shore for the safe off loading of cargo.

Besides undertaking the design and marketing of its products, the company undertakes thein-house assembly, installation, commissioning and maintenance activities required for its


products. Large mechanical assemblies and bare printed circuit boards are procured fromexternal suppliers to the company’s drawings. The company also undertakes thedevelopment of comprehensive support manuals for its products.

Sea Technik Ltd markets its products world-wide, and these markets include Europe, theUSA, and increasingly Japan and Korea. The company’s customers are ship builders andmajor shipping fleet operators.

Industry code: Prodcom 3320 - Instruments and appliances for measuring, testing andchecking.

4 Company markets and competitive position at the start of the AE

Sea Technik Ltd operates in the marine and allied industries market places, manufacturing,installing and maintaining a number of products used to optimise fuel consumption and shipperformance within that market sector. The company also supplies specialist measurementand consultancy services for the marine industry in these areas. It provides both standardproducts as well as bespoke products designed exclusively to meet customers needs.

The company’s products include Ship Performance Optimisers, Draught and Tank Measuringsystems, Shaft Power Meters, Trim Meters, Loading Stability computers, Fuel ManagementSystems and Port Freight Systems. All of these products are based on the use of a PC anddedicated analogue plug in card system design architecture.

Sea Technik is well placed in the market with a strong reputation for providing innovativesolution to customer’s problems. It has a world wide market base exporting to Europe, the FarEast ( Korea and Japan) and the North American continent.

Currently the company has 8% of the world wide market share for its products. The maincompetitors to Sea Technik Ltd in this market area include Hoppe (Germany), ShoyoElectrical Co (Japan), McNab (USA) and WDC (USA).

The company’s Shaft Power Meter is a high value system incorporated into 40% of mediumto large sized ships during construction, for the monitoring of the power to the ship’s propellerso as to maximise fuel efficiency. The Shaft Power Meter is one of the company’s mainproducts. Sea Technik Ltd has marketed its Shaft Power Meter since the product’s launch in1989, as both a stand-alone instrument for integration into customer specific fuelconsumption control systems, and as part of the company’s Fuel Economiser system.

Sea Technik Ltd has one main competitor for the supply of shaft power meters in the world-wide ship building market . This company has approximately 60% of the market share, withSea Technik Ltd having approximately 30% market share.

The technological solution employed by the company’s competitor involves the use of twoseparated shaft encoders to measure the torsion in the propeller shaft, and to use thisinformation to estimate power output. The solution uses low cost analogue processingtechnology.

Competition in this market is based largely on product price. The price includes the servicecontract that is associated with the setting to work in dockyard, initial sea trials andmaintenance support costs. . Typically prices of up to $20k would be charged for the product.

The reduction of product costs would therefore, provide Sea Technik with a large increase incompetitiveness, and a major opportunity to gain additional market share. The cost reduction


would also assist the company in overcoming variations in price competitiveness due toexchange rate variations.

Sea Technik Ltd’s shaft meter product uses a different non-contact method of measuringshaft power. This system is also based on the use of discrete technology, but is inherentlymore accurate, has better stability characteristics, and no wearing parts with a consequentbetter long term reliability.

Cost competitiveness is difficult to evaluate precisely, because each order is subject to aspecific bidding and contract negotiation process. In addition, each order may involve thesupply of associated services or equipment. However, it is evident that the price obtained bySea Technik Ltd’s main competitor for its products establishes the price differential that SeaTechnik Ltd can obtain for its system and therefore, the market is very cost competitive. Thislimits company growth.

The major objective of the application experiment was to reduce product cost and improvesystem functionality features so as to improve the company’s cost competitiveness. Inparticular, the objective was to improve the product’s accuracy, simplify setting up andcalibration procedures, reduce servicing costs, and to simplify the precision mechanicalassembly of parts of the rotor section hence reducing costs and speeding the manufactureprocess for this assembly.

Chart 1: Sales Trend Over The Past Three Years

5 Product to be improved

The existing Shaft Power Meter instrument enables the computation of propeller output powerby the measurement of shaft torque and shaft rotational speed. Torque in the propeller shaftis determined by measuring the surface strain in that shaft using strain gauges fitted to theshaft. This surface strain is caused by the twisting of the shaft due to the torque forces withinit and is directly proportional to that torque. Rotational speed is measured via a magneticpickup and a toothed ring fitted around the shaft which generates a pulse train whosefrequency is proportional to the rotational speed of the shaft.

The Shaft Power Meter is composed of four main elements: the Rotor Unit, the Stator Unit,the Data Signal Processing Unit, and the Display Unit. A diagram of the Shaft Power Meter isillustrated in Figure 1.

Sales (units)

90

95

100

105

110

115

120

1996 1997 1998

Sal

es (

un

its

rela

tive

to

19

96)

- %

Sales (units)


Figure 1: Diagram of existing Shaft Power Meter equipment

The Rotor Unit :- Torque is measured using strain gauges bonded to the propeller shaft. Thesignal from the stain gauge is amplified and converted to a frequency signal by a voltage tofrequency converter. The span and offset ranges of this signal are adjusted using multi-turnpotentiometers. This signal is then used to amplitude modulate a radio frequency (RF) carriersignal which is fed to a loop aerial. The existing design uses discrete analogue componentson a plated through hole ( PTH ) printed circuit board ( PCB ). This PCB is mounted in a largemechanical housing attached to the rotor unit. Power for the rotor unit is derived from a rotarytransformer with the secondary wound on the rotor unit.

The Stator Unit :- The primary coil and the power drives for the rotary transformer areprovided by the stator unit, which also houses the electronics circuitry for demodulating thetorque signal. Shaft speed is measured via a magnetic sensor mounted on the stator unitwhich is activated by a ring of teeth cut into the metal of the rotor unit supporting assembly.The speed and torque signals are then fed to the data signal processing unit.

The Data Signal Processing Unit :- This unit is comprised of a purchased, commercialdata acquisition card and a PC. The data acquisition card converts the input analogue signalsto a digital format, and transfers this data via an RS232 compatible interface to the 486 PC forthe computation of propeller shaft torque and output power. This data is then fed via anotherRS 232 port to the display unit.

The Local Display Unit :- This display unit uses a high brightness vacuum fluorescentdisplay which accepts data via a RS 232/RS485 interface.

“Dual Ring”Rotor Assembly

PropellerShaft

StatorUnit


Photograph 1: Existing Product In Situ in Ships Engine Room

The weaknesses in the design of the existing Shaft Power Meter occur in the following areas:-

1) Rotor board size: The use of discrete analogue circuitry and plated through holecomponent technology results in a large circuit board which requires a substantial, dual ringmounting structure for attaching and supporting the circuit board to the propeller shaft. Thecosts incurred by this mechanical assembly represent 38% of the total product costs.

2) Set-up and calibration: With the existing system, set-up and calibration is performed onsite by adjusting the rotor board’s span and offset potentiometers. This has to be undertakenwhen the shaft is stationary and the protective PCB cover removed. A dummy bridge is usedto adjust the span control. The zero offset setting has to be adjusted to take into account theresidual strains that remain in the propeller shaft due to bearing friction. The calibrationprocedure requires the rotation of the propeller shaft forward one revolution using the ship’sturning gear and the measurement of the zero reading, and then repeating the procedure byrotating the shaft backwards. The zero point is then assumed to be mid way between thesereadings and the potentiometer adjusted accordingly. The need to access the rotor circuitboard potentiometers prevents calibration data being acquired during sea trials using remoteprogramming techniques, and adds to the commissioning delays required in the ship buildprocedure.

3) Fault diagnostics: Fault diagnostics require the use of standard test instruments and aprocess of stepwise testing of the circuit elements. This is a lengthy process.

4) Reliability: Reliability is ultimately governed by the strain gauge which is susceptible to driftin service and damage in the harsh environment encountered in the ship’s engine room. Theusual practice is to bond two sets of strain gauges to the shaft so that if one set fails the otherset can be connected to the interface circuitry. This however, requires the attendance on siteof a company engineer or agent to connect and to repeat the set up and calibrationprocedures for these new gauges.

The introduction of microcontroller technology will also offer the company the additionalbenefit of removing the need to source components that are moving towards obsolescence,and are becoming increasingly expensive and difficult to locate.

6 Description of Technical Improvements

The existing design of the Shaft Power Meter has several disadvantages with regards toreliability, flexibility, manufacturing costs and ease of calibration. The objective of thisApplication Experiment was to address these disadvantages and to produce an enhanced


system design by using an embedded microcontroller. The redesigned system design isillustrated in the block diagram of Figure 2. The microcontroller incorporated in the rotor unitnow performs several of the system’s functional requirements using its integratedperipherals, and this together with the use of Surface Mount Technology (SMT) componentshas reduced the size of the board mounted on the propeller shaft significantly.

The functions now performed by the Rotor Unit in the redesigned system include:

1. The ability to incorporate a dual strain gauge interface to measure torque and to providesensor redundancy in the case of strain gauge failure.

2. In situ re-programmability so that span and offset calibration can be achieved by remotesoftware parameter adjustment. To prevent accidental corruption or interference with thenormal operation of the system these reprogramming features have been implemented asa separate mode of operation (calibration mode). This mode can only be invoked byinputting a series of ‘hidden key’ strokes into the local display.

3. The measurement of rotor speed via a magnetic sensor mounted on the rotor board.

4. Communications from the rotor unit using a serial port on a microcontroller and afrequency modulated (FM) telemetry system with data failure feature monitored by thestator unit.

5. Data processing of strain and speed sensor data to compute the required outputparameters, to generate the display data and to monitor system operation.

6. Transfer of the processed result data via the FM modulator to the stator board.

7. Storage memory for the microcontroller’s program, and calibration data.

8. System watchdog timer functions to provide automatic recovery procedures after powerfailure.

9. Monitoring of the main power supply level, the bridge output voltage and other parametersto increase accuracy and allow in system diagnostics.

Improved voltage regulation of the supply received via the rotary transformer, and addedfeatures including brown out protection.

Figure 2: Block Diagram of the Improved Shaft Power Meter

ROTOR UNIT

POWER SUPPLYRECTIFICATION

REGULATION

MICROCONTROLLER

FMMODULATOR

& AERIAL

CONFIGURATIONDATA /MEMORY

ROTARYAIR GAP

TRANSFORMER

SPEEDSENSOR

INTERFACE

BRIDGEEXCITATION &

AMPLIFIER

PRIMARYAC

POWERMODULE

SPEEDSENSOR

STRAINGAUGES

STATOR UNIT

AERIAL &FM to RS232CONVERTER

DISPLAYUNIT

PCINTERFACE

PROGRAMMINGPORT

The integration of most of the system’s functions into the Rotor Unit has reduced thecomplexity of the Stator Unit, so that the functions performed by this unit now consists of only:

1) Power supply generation and power transfer interface to the rotary transformer.

2) FM to RS 485/RS232 conversion to allow a PC or other equipment to communicate withthe Rotor Unit for calibration and diagnostic purposes.

The redesigned system will now be able to interface directly with the existing display unit, asthe display data input is now generated directly by the micro-controller. This has removed therequirement for the PC. It has also enhanced the system by the provision of additionalfeatures including:

• software calibration

• automatic detection of strain gauge failure and switching to the alternate gauge

• improved fault diagnostic as a result of localised processing using the embedded micro-controller on the rotor unit.

Photographs 2 and 3: Prototype of the Improved Shaft Power Meter


7 Choice and Rationale for the Selected Technologies, Tools andMethodology

Evaluations of the alternative solutions possible for improvement of the Shaft Power Meterwere undertaken with considerations given to the following criteria :- capability to produce thedesired system enhancements, the capacity to reduce rotor circuit board size and cost, therequired design flexibility to enable specific ship manufacturers requirements to beaddressed, the risk associated with the acquisition of new skills by the company, and theadaptability of the new technology to other products existing within the company. The designalternatives examined are classified into the following areas.

1. Use of the existing discrete component design to generate improvements inperformance and reduced size by using SMT component technology.

Inspection of the existing systems design indicated that the only method of reducing systemcalibration times and of improving system reliability was to increase the functionality of therotor board. The technical improvements achieved by the incorporation of more discreteanalogue or digital devices on this board were limited to the introduction of higher performingamplifiers with better drift and stability specifications, improvements in the RFcommunications and power supply link, and the use of additional programmable gainamplifiers and associated digital control circuitry to provide a programmable calibrationfacility. However, this design solution would have required several additional discrete devicepackages fitted on to the rotor circuit board. The use of SMT device technology would haveprovided some gains in size reduction for the circuit board as well as the benefit of introducingthis new technique to the company, but the estimated size reduction for the enhancedfunctionality board was only down to 60% of its original size. This size reduction would nothave allowed the company to remove the use of the dual ring supporting structure currentlyemployed to support the rotor circuit board. The use of an external PC to process the sensordata would also have still been required. Therefore, no major improvement in reducingmanufacturing costs would have been achieved by the use of discrete device, SMT packagetechnology. The ability to introduce customer specific additional product features was alsolimited when compared to the microcontroller technology option.

2. FPGA /PLD device technology.

The major application area of digital FPGA or PLD components in the restructured ShaftPower Meter system was in the counting of the speed sensor pulses, and the control of anyprogrammable analogue components on the rotor board. The use of an FPGA device toperform the data processing algorithms and display data generation currently performed bythe 486 PC was not technically viable. As the existing rotor unit circuit board uses mainlydiscrete analogue devices and the FPGA device offered no advantages in interfacing to thesedevices, the use of FPGA technology would not have significantly reduced the size of the rotorboard. This solution therefore still required the use of the costly dual ring supportingmechanical assembly and the use of the 486 PC for data processing.

3. Application Specific Integrated Circuits (ASICs)

The Shaft Power Meter is a high value product sold in small quantities. The low volumes ofASICs required made this technology option an uneconomic solution in terms of thedevelopment, NRE and ASIC unit costs. In addition, this solution does not address theflexibility criteria listed above.


4. Microprocessor/ Microcontrollers.

The requirement for a high level of device integration to reduce the size of the rotor circuitboard led to the rejection of microprocessor devices because of the number of additionalintegrated circuits required for their external memory, peripheral and interface circuitry.

Microcontroller devices with their higher level of peripheral integration offered greater benefitsin terms of circuit board size reduction and were therefore preferred to the microprocessoroption.

The use of low cost 8 bit embedded microcontrollers allowed the removal of the PC. Thehigher level of integration realised a much smaller circuit board requiring only a smaller singlering mounting arrangement. This factor reduced the costs of the redesigned systemdramatically.

The ability to reprogram the microcontroller also reduced design risks by the use of softwarerevisions, and provided Sea Technik Ltd with the expansion capability to meet futurecustomer demands for the product.

The company, assisted by the subcontractor, evaluated the relative merits of using a high-level language such as ‘C’, compared to a lower-level approach using assembler. Given thatSea Technik Ltd wanted to develop a detailed understanding of the interaction of the hardwareinterfacing to the microcontroller, it was decided to opt for the assembly languageprogramming for this particular project. Now that Sea Technik Ltd are skilled and familiar withinterfacing and addressing a range of external hardware modules, the next development willprobably use C as the programming language.

The decision to use assembler was also helped by the availability of low cost microcontrollerdevelopment tools such as in-circuit emulators and software simulators. Ease of use wasalso a prime requirement, and the technological step had to be one which Sea Technik Ltdcould make in a short space of time. Assembly language program development appeared tofit the bill, and this decision was evaluated as being the correct choice .

The choice of software tool was also dictated by the need to develop ‘custom’ self-test andinstallation software. Each ship installation is slightly different, and therefore a basic self test‘kernel’ is adapted for the particular installation. Writing the self-test code in assemblerallowed for efficient code generation, as well as enabling simple changes which could berapidly made.

The system software operates in two modes, viz.:

Mode 1: The normal running mode in which data is gathered, processed and thendisplayed.

Mode 2: Set-up, calibration and system diagnostics when data is downloaded to thesystem via the local display unit.

The use of the set up and calibration mode greatly simplified the in-house production testingprocess required. Whilst it was originally conceived that surface mount devices would beused, the unavailability of critical components, for example the strain gauge pre-amplifier, inpin in hole technology options only meant that the company continued to adopt this pin in holeassembly method. Final design proving testing was undertaken by installing the system onone of the company’s existing clients vessels to demonstrate the system’s performanceunder ‘field’ conditions.


The choice of microcontroller was dictated by many factors including the following :

• Memory size (ROM and RAM)• Number and type of inputs and outputs• Processing speed required, hence clock frequency• Availability of OTP (one time programmable) and EPROM parts for development• Unit cost• Package availability (ie pin-in-hole or surface mount)

The selected choice of microcontroller contained the following attributes :

• 4k ROM for program memory; 128 bytes of RAM for data memory• 4MHz instruction cycle time• 8 lines of Input / Output• Available in OTP and EPROM versions• Target cost for the OTP part of 4.5ECU• OTP part available in ‘through hole’ package

8 Expertise and Experience in microelectronics of the Company and thestaff allocated to the project.

Prior to the application experiment, Sea Technik Ltd’s design expertise concentrated on theability to configure systems to meet customer needs from a standard range of sub systems.Typically the company’s designs were configured around the use of a standard PC chassis toprovide the processing power required to implement the required algorithms. The interfacesto the PC were generally provided by purchased data acquisition cards, although occasionallythe company undertook the design and manufacture of low complexity analogue technologycards to meet specialised sensor input requirements. The design of these circuits used PTHdevices only, and to support this device technology Sea Technik Ltd undertook the lowvolume assembly of the PTH circuit boards.

Sea Technik Ltd’s electronic engineering expertise was limited to the design of simpleanalogue interface circuits, and the production of double sided printed circuit board layoutsusing a mechanical drawing PC based tool. The company did not use schematic capture andautomated circuit board layout tools. Testing of the company’s products was undertaken inhouse using manual testing techniques and basic test equipment. Sea Technik Ltd does nothave an Automatic Test Equipment facility.

The company employs software engineers with high level PC based programming experienceand systems design experience. Sea Technik Ltd did not have a digital hardware design anddevelopment capability, or any design experience in the use of micro-controller devices.

The company allocated the following staff to the application experiment:

• Technical Manager - This person had several years experience in the Royal Navy assonar training officer, before undertaking a Computer Sciences degree. He had twoyears computing experience since qualifying. In the application experiment thisindividual acted as the Project Management

• Engineer 1 - Although this person had no formal qualifications, he had acquired goodanalogue design and test skills over 20 years in industry. This person was responsiblefor the specification, development and testing of the embedded microcontrollerhardware system.


• Technician - This person was qualified to technician level in basic electronics, andhad 3 years experience in testing and commissioning existing systems. Thetechnician assisted in the prototype testing stages.

9 PHASED WORK PLAN FOR THE APPLICATION EXPERIMENT

The programme of work involved in the application experiment is described in this section.The programme is described in terms of the major tasks undertaken.

Task 1 Engineer Training

This task involved the formal training of the company’s engineers in the selectedmicrocontroller device, the techniques and methods used for interfacing both digital andanalogue signals into the microcontroller, and the processing of these signals. This trainingwas complemented by a short presentation to all of the company’s staff on the technologyimplementation so that all aspects of concern could be identified prior to projectimplementation.

The training was provided by the selected design subcontractor, and continuous training wasprovided throughout the application experiment, specifically in the area of the use of CADtools for schematic capture and net-list generation.

The planned company engineer days allocated training were 13 person days. The designsubcontractor conducted the initial microcontroller training activity in the first month of theapplication experiment. Thereafter the training progressed by considering issues as theyarose, detailed considerations of options were explained by the subcontractor to develop a‘feel’ for the design solutions, and the knowledge on the methods to be implemented indelivering the optimum solution was developed. The actual company engineer days allocatedto training were 13 person days.

Task 2 Design Specification

During this task the detailed functions to be performed by the improved Shaft Power Meterwere agreed and formalised, and the implementation methods to be adopted were defined inthe hardware and software design implementations. The specification process defined therequired accuracy of the measurements, the communications protocols, and the final displayformat for the system. An important aspect of the specification process was the definition ofall the self test and functional test methods to be adopted in the improved Shaft Power Meter.

The specification phase proved a slightly problematic area for the company. The major issuewas that once the awareness of the ‘power’ of the microcontroller device technology becamefully apparent then options to the Shaft Meter previously requested by customers could nowbe incorporated as standard features. This meant that the product specification started toprovide so many non-standard features as to make the specification a complex document.Eventually, the number of non-standard options to be incorporated was limited to thoseconsidered most important. The specification task was undertaken jointly by the company’stechnical Manager and engineer.

The role of the subcontractor during the task was to provide input into the evaluation of thespecification and in reviewing the documents produced for completeness and adequacy. Thevalue of the subcontractor’s ability to abstract from the lower level detail entered into by thecompany engineers in considering the options put forward and instead to focus on the overall‘picture’ and to interpret the requirements from this higher level perspective.


The company planned for 17 person days company effort in this task. The actual expenditurewas 24 person days because of the wider range of options considered by the company.

Task 3 Hardware Design

The system hardware implementation adopted a modular design approach, involving anumber of small circuit boards, to provide a standard, but improved Shaft Power Meterproduct.

The company’s design engineer and the subcontractor jointly partitioned the design into theoptimum circuit board level implementation, and defined the detailed interfaces between thesemodules. The task involved the development of sensor interface modules, output modules,and a display module. The partitioning of the design into various modules allowed thecompany engineer to undertake the design task for selected modules under the supervision ofthe sub-contractor. This not only developed the company engineer’s capability in terms ofmicro-controller hardware design, but allowed the engineer to benefit from advice on designoptions and configurations as well.

The company engineer conducted the schematic capture and circuit board layout tasks usingnew CAD tools procured for the task. The subcontractor support in undertaking this taskmeant that the development of the circuit boards was completed without major problemsbeing encountered.

The role of the subcontractor in undertaking the hardware design task was to advise on thesystem design solution, the partitioning of this design into a set of standard modules, and insupporting the detailed design activity. This design support activity included the provision oftechnical advice at the outset of the design task so as to arrive at the correct sub-systemimplementation approach, component selection advice, limited design activities, detailedtechnical discussions, and the detailed review of the circuit schematics at various stages toensure adequacy (especially for the testability of the board). The subcontractor provided therequired inputs in a timely fashion, and the hardware design task highlighted the benefits ofthe good integration between the subcontractor and the company’s engineer.

The hardware design task was scheduled to require 43 person days of company effort tocomplete. The actual time taken was 57 person days. The variation was largely caused by theadditional time required to produce the layout data and interconnection data information for theadditional low cost modules incorporated in the system design solution.

Task 4 Software design

This task adopted the same basic approach as in the hardware design task; functionalpartitioning to each module, module design, and the joint development of the operational codefor these modules. The task involved the development of assembly code, the simulation ofthese code modules for correct operation, and the initial software and hardware integrationtesting. The software also included system diagnostic tests, and the generation of diagnosticdisplay data for communication to the display unit.

The task was originally envisaged as being led by the subcontractor with the companyengineer supporting in a learning role. However, the company engineer was able to undertakea more active role, and was actively involved in the design process. This has meant that thecompany engineer can now undertake microcontroller program development independently.

The role of the design subcontractor in this task was to undertake the design authority for thedevelopment process, to jointly develop the embedded microcontroller code. Thesubcontractor provided design guidance and advice on embedded software development


techniques to the company engineer, and advised on the simulation and test methods to beadopted in demonstrating the code. An associated, and important, aspect of advice was themethodologies to be used for documenting the code, recording this information, and indocumenting the build mechanisms.

The software design task was scheduled to require 45 person days of company effort tocomplete. The actual time taken was 52 person days. The variation was caused by theengineer’s ability to undertake a more active development role than was originally consideredpossible, and a somewhat reduced involvement from the subcontractor.

Task 5 Prototype Testing

The company engineers led this task with subcontractor support when requested. The testingprocess was complex, and involved the proving of all of the functional aspects of theequipment as laid down in the technical specification. The application of the extensive self testmodes built into the improved equipment removed the need for the development ofspecialised test equipment to evaluate the performance of the system, and allowed the use ofstandard test equipment.

Each of the modules was tested individually, and fault finding and diagnostic activities wereperformed at this level wherever possible. This meant that system functional evaluations wereless problematic because lower level faults had been eliminated. The use of standard in-house Shaft Power testing methods enabled the system performance to be demonstrated.

The role of the sub-contractor in this task was to provide support when requested. Thesupport was generally in the area of system diagnostics, and design correction whenrequired.

The company had planned 31 person days for these tasks. The actual number of days was42 person days. The variation was due to the unfamiliarity with debugging methods for themicrocontroller implementations, the use of two people to distribute the knowledgedevelopment.

Task 6 Technical Management

This task involved the definition of the company’s technical objectives, management of theproject on a day to day basis, subcontract preparation and management, development ofplans for the production and testing of the improved product, and input into the selection ofappropriate CAD/CAE tools. The technical management activity ensured that projectmilestones were achieved, and that monthly technical and progress reviews were conducted.

One major activity conducted under the technical management role was the collection of thelarge number of data sheets, notes, drawings, and miscellaneous files. This resulted in thecreation of the 'Build File' and 'Technical File’. The first is an internal document that providesall the information needed to manufacture a Shaft Power Meter, and the second an internal filethat provides all possible relevant information for customer and product support. This wasconducted relatively smoothly because of the advice provided by the design subcontractor inthe design phase of the application experiment.

The task was undertaken solely by the Technical Manager, and required 30 person dayseffort. This was as planned.


The knowledge development process included training supplied by the selected subcontractorin microcontroller technology and the use of the CAD tools, the provision of design advice,support and training in the specification and systems design tasks, and by the hands onactivity of designing the hardware and embedded software under the management of thedesign subcontractor. Knowledge in testing microcontroller circuits and software was alsodeveloped in a ‘hands on’ manner with the support of the design subcontractor.

Figure 4: Simplified workplan Illustration.

The simplified work plan (figure 4) indicates that the plan originally produced identified asequential approach to the major tasks. However, as a result of the modular redesign theapplication experiment was conducted as a series of module developments, and this enabledthe hardware and software development to progress in parallel to a large extent. This wasadvantageous not only from a knowledge development process, but because the additionaltime involved in the specification phase was recovered and because it allowed engineers towork in parallel on the application experiment. This approach in retrospect is an improvementover the original plan.

Time Plan for Application ExperimentTask Description Project Months

1 2 3 4 5 6 7 8 9 1 0PLANTrainingSpecificationHardware DesignSoftware DesignFunctionality TestingDesign RevisionsFinal Testing

ACTUALTrainingSpecificationHardware DesignSoftware DesignFunctionality TestingDesign RevisionsFinal Testing


The resources required to complete the application experiment are summarised in Table 2.

Task CompanyPlanned Effort(person days)

CompanyActual Effort

(person days)

Cost ofsubcontractor

(K EURO)

Training 14 13 1.6Specification 17 24 1.8Hardware Design 43 57 4.8Software Design 45 52 6.0Evaluation &Testing 31 42 1.3Technical Management 30 30 -

Total 180 218 15.5

Table 2: Resources Used in the Prototype Microcontroller Development

The reasons for the variation in resources required from the company have been describedunder each task description above.

10 Subcontractor Information

The selection criteria used to appoint a subcontractor includes the following :

• Knowledge and experience of the installation, operational, and maintenance difficultiesassociated with marine ancilliary equipment.

• An appreciation of the total ‘product lifecycle’ costs when considering different approachesto the design of electronic modules

• A working knowledge of applying strain gauge measurement to a ‘heavy’ industry such asshipbuilding.

• Ability to critically evaluate a variety of software and hardware design approaches, and beable to optimise the choice based on the total ‘product lifecycle’ costings.

• Experience of designing high-reliability electronic modules that are capable of operating ina rugged environment without regular attention or maintenance.

• Experience of working with a wide range of microcontroller device families,

Sea Technik Ltd approached a number of commercial organisations and Universities, underthe guidance and support of the TTN. Sea Technik Ltd eventually settled on TI Design as acompany who most closely fitted the above list of attributes. An important consideration wasthe approach and attitude of the subcontractor, as Sea Technik Ltd wanted to ensure that thepartnership would underpin the long-term success of the application experiment.

The supporting factors behind Sea Technik Ltd’s selection of TI Design included the following:

1. TI Design had several years design experience in supplying equipment for the marine andallied industries, including the design of instrumentation and sonar equipment for thismarket.

2. TI Design had produced several systems designs based on the use of embedded micro-controllers, microprocessors and digital signal processors.

3. The selected subcontractor had previous experience of developing products based on theselected micro-controller, and in program development using both C and assemblyprogramming techniques.


4. The use of SMT devices in development projects undertaken by TI Design is a normalactivity, and this capability assisted the transfer of SMT design layout rule knowledge tothe company.

5. Sea Technik had a long relationship with the Director of the Subcontractor Company as aresult of his previous work in sonar systems design. The non-competing backgrounds ofthe companies enabled the negotiation of an acceptable contractual Intellectual PropertyRights (IPR) clause.

The subcontractor operated under a formal contract to Sea Technik Ltd Systems. Thiscontract defined firm deliverables for the contract, and identified stage payments related tothese. There were no problems encountered in the management of this subcontract, and alldeliverables were supplied as required. The company obtained as deliverables all drawingsand code produced by the subcontractor, and under the contract’s terms the company alsoobtained the ownership of the intellectual property rights for these deliverables.

The selected subcontractor TI Design was not immediately local to the company (about 1hour away), but the company identified the previous background experiences above as crucialfor the success of the AE. During the application experiment the subcontractor was at thecompany’s site for approximately 40% of the time between specification approval and finalprototype testing. At other times regular e-mail, fax and telephone communications were usedto progress design aspects.

11 Barriers Perceived by the Company in the First Use of the ApplicationExperiment Technology

The main perceived barriers faced by the company at the outset of the application experimentwere a lack of knowledge, concerns about supporting the technology, and concerns about thereliability of the system.

The company had no prior knowledge of or experience in using microcontroller devicetechnology. The company’s knowledge base was focussed on system development using theminimum of bespoke hardware designed items and the development of PC based softwaresystems. The company was therefore, not considering the implementation of software inembedded microcontroller-based circuit boards designed by the company. The lack ofknowledge and awareness of the potential of the device technology meant the company hadnot conducted any studies into the product improvement.

When a limited awareness of the benefits of considering microcontroller technology circuitboards was achieved, the company still had major concerns in implementing such atechnology solution. These included:

• The ability to cost the development, investment and production costs for the developmentprogramme meant that the company was faced by an uncertain economic prospect. Thiswas not satisfactory for a small company, and prejudiced the company towardsmaintaining current technology solutions if possible.

• A concern over the impact in terms of continuing to be able to offer product support to theclient. The company has limited resources in terms of persons available to conduct suchsupport activities. The risk of encountering several new, unfamiliar system problemsarising in sea going vessels requiring potentially major costs in terms of transferringengineers to the vessels at sea, additional on-board time, or extensive at-sea trials timesincurring penalty clauses. These risks, if realised, would severely impact on thecompany’s profits and credibility.

• Concerns also existed as to whether the technology could realise the performancerequired from the system or not. The prospect of investing engineering resources in a


product that would have been an expensive ‘flop’ was not one that appealed to thecompany.

• The existing products produced by the company could be commissioned using standardtest equipment which was familiar to the company’s technicians. The new technologyrequired new tools for development. The company was concerned that the system testingwould require new techniques not familiar to the company’s technicians, with a higherprospect of system failure and incorrect set up. This was conceived as an additional riskfactor.

• The appropriateness of the technology for the marine environment was also a concern.This is a hostile environment, and moving to a new device and system solution couldintroduce unforeseen technical problems.

12 Steps taken to overcome the barriers and arrive at an improved product

The initial meetings and discussions conducted with the TTN, allowed the initial technologyawareness barriers to be overcome, and as part of the investigation work carried out prior topreparing the application experiment proposal, Sea Technik Ltd worked closely with the TTNto evaluate the best technological route forward. This developed the basic companyknowledge of the technology to a level where the subsequent barriers could be addresses.

By analysing the steps closely, Sea Technik Ltd could start to see that the overall riskassociated with the project, if managed effectively, was in fact very low. However, SeaTechnik Ltd were reassured by the fact that both the TTN and the design subcontractor wouldbe on hand to ensure that the experiment progressed according to plan. This support wasdeemed vital to Sea Technik Ltd, and is one of the reasons that attracted Sea Technik Ltd tothe FUSE programme of work.

This initial consideration process also addressed the company’s concerns over costs,support and testing methods. The technology selection process led to a view of theinvestment costs required to develop the project, and to the scale of the potential economicreturns. These benefits pre-disposed the company towards investing in the microcontrollerenhancement, and the partnership proposed for the development of the product provided thepsychological comfort to move in this direction.

The concerns over testability were reduced by the prospects of being able to apply self-testmodes of operation embedded in the product. This held out the prospect of removing theneed for retraining in the use of expensive new test equipment for the company’s technicianstaff. It also addressed the problem of provision of adequate customer support through theuse of simple test menus, which could be operated by the ship’s engineer if required. Theseaspects of system design were outlined by the subcontractor at initial meetings. Thecompany’s confidence in the subcontractor’s marine electronic credentials and experiencemeant that this area of concern was reduced significantly.

Sea Technik Ltd worked closely with their selected design and training subcontractor, TIDesign, throughout the application experiment. This mode of operation built confidence in thecompany’s management that by closely working alongside their engineers the subcontractorwould assist the development of the required expertise into Sea Technik Ltd. This removedthe frustration faced by many small companies when attempting to introduce new products,processes or technology because they do not have the resources in-house. The applicationexperiment provided the opportunity to work closely with experts in the field, thus allowing theirtechnical staff to transfer knowledge into the company whilst working on a specific applicationexperiment.


13 Knowledge and experience acquired

This application experiment has resulted in the development of several new technical andmanagement capabilities in the company. The capabilities developed include:

1) Technical management skills in the area of microcontroller based product development.The company’s Technical Manager was responsible for delivering the application experimenton schedule, and in collating the related documentation to enable almost immediate transferinto production. This experience, assisted by guidance from the TTN and the subcontractor,has given the company a high degree of confidence in the use of microcontrollers.

2) System design skills based on the use of microcontrollers. The implemented system hasapplied the flexibility of this technology, and the advice provided during the systemspecification and system design / partitioning phase by the subcontractor has allowed SeaTechnik Ltd to acquire the ability to develop system solutions independently.

3) Product specification skills including an awareness of the factors to be defined formicrocontroller based product specifications. The lessons learned in defining a major systemspecification has meant a significant advance in knowledge in this area.

4) Design skills, including appropriate interfacing methods for microcontroller based systemsand the design, specification and documentation methods for microcontroller embeddedsoftware. The company can now undertake microcontroller design independently.

5) Fault location skills, including knowledge of alternative debugging techniques formicrocontroller systems. The company’s technician engineers have been trained in this area,and are capable of commissioning the existing system.

6) Improved schematic capture and circuit layout techniques using modern CAD systems.

The design capabilities that the company has achieved have exceeded that originally planned.Although all of the above issues were anticipated as knowledge development areas, thecompany feels that its staff has reached a higher level of competence in each than originallyplanned.

In summary, the company considers that it could now undertake the design activities requiredto replicate a similar product design independently.

14 Lessons Learned

The lessons learned by the company during the application experiment were:

• The adoption of microcontroller technology led to a much wider implementation of thedevice technology in the final product than was initially envisaged. The company’s originalperceptions of limited use were replaced during the application experiment by theknowledge of the versatility of the technology, and more significantly of the benefits of itslow cost and the ability of the devices to integrate functions that would otherwise haverequired several discrete devices. This aspect of the technology was unexpected, and asignificant lesson learned for future product developments.

• Originally the company’s perceptions were that the benefits of the cost saving would berelated to the elimination of mechanical assemblies, PC removal and set up timereductions. This development however, indicated that no cost increases for theassembled microelectronics occurred when the simplification of the test procedures wasalso considered.


• The company now appreciates the full benefits to be derived from the ability to include selftest modes into the product by the use of appropriate software programmes. Thisunexpected benefit derived from the use of self test features in the product were the abilityto avoid developing new production test jigs for final product functional test, the ability tointerrogate the system whilst at sea using remote telecommunications links savingsubstantial sums in travelling costs, as well as reduced commissioning time.

• The company had to adopt new design management processes for this applicationexperiment. The design implementation required the use of assembly programming andnew CAD system, and the procedures adopted for previous PC software developmentswere no longer appropriate. The company managed this process by the use of monthlymanagement reviews which allowed a firm understanding of progress and low levelimplementation methods to be gained on a continuing basis, and thereby to maintainprogress to schedule.

• The company has also learned of the benefits of adopting a complete systems andproduction planning approach at the outset of the application experiment. The importanceof clear specifications based on these considerations was important in realising theproduct design on schedule.

• The company has expanded the electronics supplier base for the new product, and nowappreciates the technical support / seminar availability etc, from this source to maintain itsskill base.

15 Resulting Product, Its Industrialisation, And Internal Replication

The improved Shaft Power meter is operational. The first unit was made available for sale inApril 1999, and already 3 units have been sold and are currently awaiting commissioning onthe targeted vessels. Additional orders are also anticipated.

The speed to market for the improved product was realised by the parallel planning of many ofthe major industrialisation tasks with the application experiment. The industrialisation processwas completed one month after the completion of the application experiment. The majoractivities conducted in the industrialisation of the improved product were:

• The development of a new mounting mechanism for the electronic unit. This wasdeveloped using a plastic mounting ring design that relied on the machining of plasticmaterial into the correct form. This was undertaken by external machining companiesusing detailed machining drawings supplied by the company. The drawings wereprepared in parallel with the application experiment, and required approximately 2 personweeks design and draughting time to complete.

• The development of a modem link for the transfer of telemetry data to and from the onvessel system. This unit required 3 person weeks effort to complete, and was developedat the end of the initial prototype stage, and prior to the final transfer to production.

• The development of comprehensive handbooks to support the product. These arerequired for the ships’ engineers during sea trials and to support on the vesseldiagnostics. Two person weeks effort was required to complete this document, and thiswas undertaken in parallel with the final prototype testing phase.

• The display unit is mounted in a standard enclosure purchased through stockists.However, the unit required detailed machining and assembly drawings to be produced tohouse the electronic assemblies and for fixing to the ship. This required 1 weeks personeffort and was conducted in parallel with the application experiment.

• Formal EMC testing was not required (for shipborne use), but the system was evaluatedto ensure this system was satisfactory. The use of a design subcontractor used to marineenvironments assisted in this regard.


The company procures bare circuit boards, and populates these in-house. It was therefore,not necessary to establish new production circuit board manufacturing suppliers.

The company estimates the total cost of the industrialisation process, including managementsupervision time, to be 15 K EURO. The parallel planning of many of the electronic andmechanical design tasks ensured that the systems were available for sale as soon as initialtrials were complete.

The company has now fully grasped the potential of the low cost microcontroller technology.The company’s products are not limited to Shaft Power meters and includes precision draftmeters, ships monitoring equipment (for example, fuel use monitoring), and specialisedequipment for specific applications in the marine environment (for example, cargo transfermonitoring systems for gas carriers). Each of these areas can potentially be improved by theuse of the technology, and such developments will be considered.

16 Economic Impact and Improvement in Competitive Position

The introduction of a microcontroller based Shaft Power Meter product by Sea Technik LtdSystems has enabled a much lower cost system requiring a single ring mounting system andminimal sea trial calibration costs to be produced. This has resulted in Sea Technik Ltdintroducing an improved product at a highly competitive price, and has given the company asignificant improvement in market position.

The main factors influencing the purchase of equipment in the highly competitive ship buildingmarket is product price, followed by reliability and performance. As the microcontrollerenhancement of the Shaft Power Meter has improved these aspects of the product it willresult in a significant increase in sales for the company.

The marine industry is essentially a bespoke market where ships are generally built to aunique specification. The ship building market is dominated by production in the Far East, withKorea producing 26% of the world’s Consolidated Gross Tonnes (CGS), and Japan producing32% of the CGS. The European ship building market, and other near markets, traditionallybuild specialist high technology specification ships. Within Europe, Spain and Italy are themain suppliers of ships in this market area.

Shaft Power Meters have normally been only installed on high technology ships, but over thelast 3 years this equipment has been specified for the more general purpose ships. BothKorean and Japanese shipyards have been using this type of equipment as a standardfeature on their ship designs. This offers a new and growing sales market for the improvedShaft Power Meter equipment.

The nature of the market is such that product price discounting by the competing companiesis commonplace, and actual sales prices are determined by related factors such as thepotential for future orders with that customer, other equipment to be purchased as part of anoverall package, etc.

The improved performance, reduced requirements in setting to work time, and the improvedcost competitiveness of the improved product allow Sea Technik Ltd to significantly improveits competitiveness. This will lead to a significant growth in sales of the product.

The main cost elements in Shaft Power Meter are the dual ring metal assembly and thebought in components, which comprise the data acquisition card and the 486 PC. Theremoval of the complexity of the support structure to a single ring assembly, and the removalof the PC lead to cost savings for the overall system of approximately 20%. The profitability ofthe product will remain unchanged as a result of the company cutting prices to gain an


increase in competitiveness and because of the adverse affects of the strength of sterling inrelation to the major competitors currency values in the short term.

The use of microcontroller device technology in improving the Shaft Power Meter equipmentwill therefore generate significant increases in sales and profits for Sea Technik Ltd, and willenable the company to greatly expand its export activities in Japan and Korea.

The impact of the improved product is illustrated in Figure 3 below.

Figure 3: Sales Of The Shaft Power Meter Before And After Improvement

The development costs for the improved product were 63 K EURO. These costs included 15K EURO industrialisation costs for the prototype unit, and the 48 K EURO EC FUSE funding.

Based on the improved sales projections for the improved product, and the expected rate ofprofitability for these products the anticipated payback period is approximately 13 months. Thereturn on investment (ROI) on the new product over a 4 year period is approximately 410%.The 4-year period is anticipated as the life of the product before further re-developmentsbecome required.

17 Best Practice and Target Audience

The application experiment has demonstrated best practice in modular design approaches tospecification and system design, best practice in terms of planning the project and theindustrialisation activity so as to reduce time to market, and in the design of systems for lowoperational and maintenance costs.

Sea Technik Ltd’s experience during this application experiment will be of particular interest tothose companies throughout the EU who trade in similar market place and will include shipyards, ship operators, marine research establishments and associated equipmentmanufacturers. The marine supply industry also has a large number of small companies in itssupplier base, and the company’s experience of adopting new technology to generatesignificant increases in export sales is expected to also be of interest to this audience. ThisApplication Experiment demonstrates the application of microcontroller technology in anextremely harsh marine environment and demonstrates how this technology increasessystem reliability and performance within that environment.

The target audience for the material will be the Directors and Technical Managers ofcompanies involved in such activities.

05

1015202530354045

1998 1999 2000 2001 2002

Sal

es (

units

)

Without Improvement

With Improvement


The targeted industrial sectors for the dissemination material includes the following sectors:

1. General mechanical engineering (Prodcom Code 2852),

2. General purpose machinery (Prodcom Code 2924),

3. Building and repairing of ships (Prodcom Code 3511),

4. Electrical equipment for engines and ships (Prodcom Code 3161),

marine propeller shaft power meter - fuse-network.com · marine propeller shaft power meter...

Documents