Intelligent sensor-actuator gateway with CAN interface Systems Engineering Lab - Daniel Thiele Project Overview

Project Team Andreas Paczynski (Supervisior) Prof. Dr. Head of SE Lab Michal Zajac (Supervisior) Dipl.-Ing. Ph.D. Student Daniel Thiele (Author) Dipl.-Ing.(FH) M.Sc. Student

Motivation Existing mobile robot chassis:  CAN is used for on-board communication  every drive unit is controlled by a central intelligence Future purposes:  Possibility for semi-intelligent behaviour  Every drive should possess a seperate µController  Communication relay to a off-unit monitoring tool  Communication between other drive units  Controllability of behaviour of the drive unit

Robot Chassis Block Diagram - System Drive Unit 1 Drive Unit 2 Drive Unit 3 Drive Unit 4 Central Intelligence CAN Bus

Drive Unit n Block Diagram - Existing Drive Unit Central Intelligence CAN Bus Drive Unit n-1 Drive Unit n+1 Motor Controller Velocity Encoder Angular Encoder Brake Switch

Resulting Problems High Bus Load  4 x 4 CAN bus modules over 1 CAN bus line  extensive bandwith usage No Data Logging  Data logging must been contributed by central intelligence  Increased CPU load

General Tasks Data logging  Saving of measured values in a ring buffer  React to requests by central intelligence Communication with central intelligence  Implementation of a basic protocol over CAN Control of EPOS positioning controller  Implementation of functions for EPOS control

Drive Unit n Block Diagram - New Drive Unit Central Intelligence CAN Bus Drive Unit n-1 Drive Unit n+1 Motor Controller Velocity Encoder Angular Encoder Brake Switch Microcontroller Board

Block Diagram – Microcontroller CAN Interface Internal Memory C P U Freescale HCS12 RS232 Interface Debugging / Monitoring Motor Controller / Encoders Central Intellegince

Activity Chart - Software Main loop Select necessary commands for drive unit Load desired drive unit CAN messages from circular buffer Check for and process central intelligence CAN commands Send CAN messages to drive unit and central intelligence Send appropriate RS232 messages to debugging unit Check for and process RS232 debug commands Initialize Digital I/O Initialize CAN / RS232 interfaces Initialize System functions Initialize Operation System Check for drive unit CAN messages and store to circular buffer

Thank you for your attention! to Mr. Daniel Thiele Homepage of System Engineering Laboratory For further information...