Team CNH

Design a less expensive propulsion control system with equivalent or better performance than existing hardware for Hydrostatic Windrower Machine.

Mission Statement:

Forward

Customer Wants

Low Cost Very Reliable Easy to Use Easy Maintenance High Level of Accuracy Comfortable to Use Minimal Machine Redesign Highly Repeatable Continued Operation Ability High Perception of Safety

Constraints

System Must Be Safe System Must Meet all ASAE Codes Total System < $300.00

Benchmarking

Current CNH System

Benchmarking

John Deere Hesston

Design Metrics Time to Reach Neutral Total Cost Response Time Serviceability Index Component Effects Energy Usage Repeatability Rate Number of Parts Changed

Design Target Values Stopping Time < 10 Seconds Total Cost < $250.00 Response Time < ¼ Second Serviceability Index < 237 12 Volt System, Draw < 30 Amps Mean Time Between Failures > 3,240

Hours Number of Parts Replaced <4

Design Breakdown

Motion Actuation

Motion Actuation

Concept 1- Rotary Actuator

Motion Actuation

Concept 2- Linear Actuator

Actuation Design Decision

Chose to Use A Linear Actuator Because:

• Least Expensive Solution• Smallest Amount of Machine Redesign• More Durability• Lowest Energy Requirements

Safety Return

Safety Return

Concept 1- Engine ShutoffBenefits:Least Expensive and Easiest to Implement

Major Problems:Complete Loss of Operation After FailureCustomer Perception of “Unsafe”

Safety Return

Concept 2- Collapsible Linkage

Normal Operating Conditions Failure Mode

Safety Return

Concept 3-Hydrostatic Braking

Safety Return

Concept 4- Hydro-Mechanical Failsafe

Safety Return Design Decision

Chose the Hydro-Mechanical Failsafe Because: Safe Low Cost Quick Time to Reach Neutral Position Ability to Use Other Functions After

Propulsion Shutoff

Final Design Assembly

How Does it Work?

Reverse vs. Forward Engine Shutoff

Machine will not be cutting crop in reverse

Center of gravity is close to front of machine

Reverse speed much less than maximum forward speed

Machine will not be moving in reverse on roadways

Future Controller Design

Validation- Machine Tests

How Will Machine React if Engine is Shutoff While Operating in Reverse?

Validation- Machine Tests

Engine RPM

Cylinder Position

Ground Speed

Validation- FMEA

Failure Modes and Effects Analysis• Identifies Potential Failure Modes

• Estimates Occurrence Rate

• Assess Severity of Failure

• Evaluates Potential To Detect Failure

• Recommends a Design Action to Lower Risk if Needed

Sample FMEA

Validation- Cost Breakdown

Validation-Stress Analysis

Path Forward

Finalize Actuator Supplier Build Prototype Write Controller Code Test Mean Time Between Failure in

Lab Perform Field Tests

QUESTIONS ?

Final Design Layout

Spring Return Mechanism

Existing CNH Return Spring

Hydraulic Cylinder + Valve

Linear Actuator

Hydraulic / Spring Connection

To Pintel Arm

To Spring Assembly

Hydraulic Connection

Actuator Mounting Bracket

Actuator-Cylinder Connection

Controller Diagram

DC MotorCi PWM Screw

Linear actuator

Cd

rd ed ri ei ydyi

rd: Reference Displacement

ed: Error Displacement

Cd: Displacement Controller

Ri: Reference Current

Ei:Current Error

Ci/PMW: Current Controller

Yi: Output Current

Yd:Output Displacement

Validation- Stress Analysis