targeting the scicos codegenerator for embedded applications

Rapid Controller Prototyping Linux RTAI Scicos Implementation Examples Conclusions

Targeting the Scicos Codegenerator forembedded applications

Ing. Roberto Bucher

Scuola Universitaria Professionale della Svizzera Italiana (SUPSI)

Paris - 1.7.2009

Objectives

(Prices in Euro) Commercial ProposedControl design environment solution

Core SW 1950.- 0.-

Control SW 1000.- 0.-

Graphical GUI 3000.- 0.-

Code generator 7500.- 0.-

RT target 3000.- 0.-

Objectives

Outline

1 Rapid Controller Prototyping

2 Linux RTAI

3 Scilab/Scicos and Linux RTAI

4 Implementation

5 Examples

6 Conclusions

Introduction

Control Design Loop

specification

modellingidentification

controldesign

simulation

implementation

verification

Introduction

Rapid Controller Prototyping - Requirements

2 main components1 An OS with hard real-time features2 A Computer Aided Control System Design environment

including a code generator

→ Linux RTAI + RTAI-Lab + Scilab/Scicos

Basics

The Linux RTAI project

Hard real-time extension to the Linux OS

Based on the ADEOS pipeline (with some improvements!)

Free Open Source Software (FOSS)

Implementation of hard real-time controllers using generalpurpose hardware

Same PC for the controller design, the hard real-timecontroller task and the soft real-time monitor task

Hard real-time in kernel and user space

Distributed control through the net rpc module

Basics

Linux RTAI - Features

Latency: < 10µs depending on the HW

Typical sampling frequencies: 1 . . . 10kHz

RTAI-Lab

The GUI application - xrtailab

RTAI-Lab

PC with HRT task and xrtailab

PC with HRT task PC with xrtailab

Network

UDP/IP

RTAI-Lab

PC with HRT task and xrtailab

PC with HRT task PC with xrtailab

Network

UDP/IP

RTAI example 1

Systems controlled with Linux RTAI

http://www.inrialpes.fr/sed

Cycab (INRIA)

Biped Robot (INRIA)

RTAI example 2

National Radio Astronomy Observatory controlled withLinux RTAI - West Virginia

http://www.gb.nrao.edu/43m/

Add-ons

Add-ons for Scilab/Scicos

The link between Scilab/Scicos and Linux RTAI is implementedthrough:

A code generator → RTAICodeGen .sci.

A rtmain.c (main file for the real-time task) specific for theScilab/Scicos environment.

An external ”template Makefile”

A new scicos palette RTAI-Lib.cosf.

Macros for the new blocks (Scicos interface functions).

A RTAI library specific for the new Scicos blocks (Scicosimplementation functions).

The code generator

RTAICodeGen .sci

The code generator used in RTAI is a modification of the standardScicos code generator

Only stand-alone generation with specific main procedure(rtmain.c)

Sensors and actuators are integrated in the Scicos blockdiagram as specific custom peripheral blocks

Each block can be identified by a name which is then referredin RTAI-Lab

The code generator

Code generation

SineSine

SCOPEScopeSCOPEScope

comedi0 CH−0COMEDI A/Dcomedi0 CH−0COMEDI A/D

comedi0 CH−0COMEDI D/Acomedi0 CH−0COMEDI D/A

Design

Superblock

RTAICodegen .sci

Compiling and Link

rtmain.c libsciblk.a Scilab lib

Hard real-time stand-alone executable

RT exec

The code generator

Code generation

SineSine

Design

Superblock

RTAICodegen .sci

Compiling and Link

RT exec

The code generator

Code generation

SineSine

Design

Superblock

RTAICodegen .sci

Compiling and Link

RT exec

The code generator

Code generation

SineSine

Design

Superblock

RTAICodegen .sci

Compiling and Link

RT exec

The code generator

Code generation

SineSine

Design

Superblock

RTAICodegen .sci

Compiling and Link

RT exec

The code generator

Code generation -Details

Superblock

rtai.gen

standalone.cmd rtai.mak

model.c model Cblocks.c Makefile

The code generator

Superblock

rtai.gen

The code generator

Superblock

rtai.gen

The code generator

Superblock

rtai.gen

The code generator

Target specific files - The “gen” file

rtai.makstandalone.cmd

The code generator

Target specific files - The “cmd” file

[CCode,FCode]=gen_blocks()[Code,Code_common]=make_standalone42();files=write_code(Code,CCode,FCode,Code_common);Makename=rt_gen_make(rdnom,files,archname);ok=compile_standalone();

The code generator

Target specific files - The “mak” file

all: ../$$MODEL$$

CC = gcc

CC_OPTIONS = -O -DNDEBUG -Dlinux -DNARROWPROTO -D_GNU_SOURCE

MODEL = $$MODEL$$

OBJSSTAN = rtmain.o common.o $$MODEL$$.o $$OBJ$$

SCILIBS = $(SCIDIR)/libs/scicos.a $(SCIDIR)/libs/poly.a $(SCIDIR)/libs/calelm.a$(SCIDIR)/libs/blas.a $(SCIDIR)/libs/lapack.a $(SCIDIR)/libs/os_specific.a

OTHERLIBS =

ULIBRARY = $(RTAIDIR)/lib/libsciblk.a $(RTAIDIR)/lib/liblxrt.a

CFLAGS = $(CC_OPTIONS) -O2 -I$(SCIDIR)/routines -I$(SCIDIR)/routines/scicos $(C_FLAGS) -DMODEL=$(MODEL) -DMODELN=$(MODEL).c

rtmain.c: $(RTAIDIR)/share/rtai/scicos/rtmain.c $(MODEL).c

cp $< .

../$$MODEL$$: $(OBJSSTAN) $(ULIBRARY)

gcc -static -o $@ $(OBJSSTAN) $(SCILIBS) $(ULIBRARY) -lpthread $(COMEDILIB) -lm

@echo "### Created executable: $(MODEL) ###"

Scicos blocks

The new Scicos palette

Square

test.datextdata

SENSOR

SCOPEScope

METERMeter

LEDLed

ACTACTUATOR

MBX1Mbx Send Ovw

MBX1Mbx Rcv no blk

MBX1Mbx Send if

MBX1Mbx rcv blk

comedi0 CH−0COMEDI A/D

comedi0 CH−0COMEDI D/A

comedi0 CH−0COMEDI DI

comedi0 CH−0COMEDI DO

SEM wait

SEM1SEM signal

BlockC RTAI

0Fifoout

0Fifoin

Scicos blocks

Specific blocks for RTAI-Lab

METERMeterMETERMeter

LEDLEDLEDLED

Scicos blocks

LEDLEDLEDLED

Scicos blocks

LEDLEDLEDLED

Scicos blocks

LEDLEDLEDLED

Other palettes

Additional palettes

The ”main” file

The main file rtmain.c

3 threads:

Main thread rtMain

Hard RT thread rt BaseRate

Communication thread with the GUI client applicationrt HostInterface

The ”main” file

The rt BaseRate thread

WaitTimingEvent

HARD real−time

SOFT real−time

NAME(MODEL,_isr)(double t);

NAME(MODEL,_init)();

NAME(MODEL,_end)();

Adding new blocks

Adding a new block

Each new block needs

An interface function (“.sci”)

An implementation function (“.c”)

The inverted pendulum

The Inverted Pendulum

Particular of the RF encoder

i1 φ1

receiver

Driver

CAN BUS

PC with HRT

controller

Encoder+RF sender

Reduced orderobsever

The Scicos scheme

SCOPEScope

Safety block

Real Plant

LQR_controller Input_ref

Swingup_controller

0.21Switch

i1 φ1

receiver

Driver

CAN BUS

PC with HRT

controller

Encoder+RF sender

The Scicos scheme

SCOPEScope

Safety block

Real Plant

Swingup_controller

0.21Switch

i1 φ1

receiver

Driver

CAN BUS

PC with HRT

controller

Encoder+RF sender

The Scicos scheme

SCOPEScope

Safety block

Real Plant

Swingup_controller

0.21Switch

i1 φ1

receiver

Driver

CAN BUS

PC with HRT

controller

Encoder+RF sender

The Scicos scheme

SCOPEScope

Safety block

Real Plant

Swingup_controller

0.21Switch

i1 φ1

receiver

Driver

CAN BUS

PC with HRT

controller

Encoder+RF sender

The Scicos scheme

SCOPEScope

Safety block

Real Plant

Swingup_controller

0.21Switch

i1 φ1

receiver

Driver

CAN BUS

PC with HRT

controller

Encoder+RF sender

The Scicos scheme

SCOPEScope

Safety block

Real Plant

Swingup_controller

0.21Switch

Ball on beam

Ball on Beam

The Scicos scheme

SCOPEScope

Ball on beamControllore + Osservatore

−K−siginp.datextdata

The anti-windup controller

Saturazione

Mux C + O Direct

y=Cx+Dux+=Ax+Bu

C + O Feedback

y=Cx+Dux+=Ax+Bu

The CANopen blocks

ExpressionMathemati..

0x02encoderEpos

0x02motor IEpos

00x02Epos Analog

X01sINIT ENC

PHI01sINIT ENC

den(z)num(z)sync

canopenEpos

Ball on beam

Ball on Beam

The Scicos scheme

SCOPEScope

Saturazione

Mux C + O Direct

y=Cx+Dux+=Ax+Bu

C + O Feedback

y=Cx+Dux+=Ax+Bu

The CANopen blocks

0x02encoderEpos

0x02motor IEpos

00x02Epos Analog

X01sINIT ENC

PHI01sINIT ENC

den(z)num(z)sync

canopenEpos

Ball on beam

Ball on Beam

The Scicos scheme

SCOPEScope

Saturazione

Mux C + O Direct

y=Cx+Dux+=Ax+Bu

C + O Feedback

y=Cx+Dux+=Ax+Bu

The CANopen blocks

0x02encoderEpos

0x02motor IEpos

00x02Epos Analog

X01sINIT ENC

PHI01sINIT ENC

den(z)num(z)sync

canopenEpos

Ball on beam

Ball on Beam

The Scicos scheme

SCOPEScope

Saturazione

Mux C + O Direct

y=Cx+Dux+=Ax+Bu

C + O Feedback

y=Cx+Dux+=Ax+Bu

The CANopen blocks

0x02encoderEpos

0x02motor IEpos

00x02Epos Analog

X01sINIT ENC

PHI01sINIT ENC

den(z)num(z)sync

canopenEpos

Ball on beam

Ball on Beam

The Scicos scheme

SCOPEScope

Saturazione

Mux C + O Direct

y=Cx+Dux+=Ax+Bu

C + O Feedback

y=Cx+Dux+=Ax+Bu

The CANopen blocks

0x02encoderEpos

0x02motor IEpos

00x02Epos Analog

X01sINIT ENC

PHI01sINIT ENC

den(z)num(z)sync

canopenEpos

Ball on beam

Videos

Sample Videos

Conclusions

Open source!!!

Complete and stable.

Able to solve complex control problems in a simple way.

It runs parallel to a MATLAB/Simulink/RTW environment inmy student laboratory

Questions

Questions?

Thank You

www.rtai.org

www.dti.supsi.ch/∼bucher/scilab.html

www.dti.supsi.ch/∼smt/laboO4.html

targeting the scicos codegenerator for embedded applications

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