response

actuator control program

analog quantity,e.g. pulse train

digital quantity,e.g. power %

interface

stimuli

sensor control program

analog quantity,e.g. light

digital quantity,e.g. light %

interface

Sequential and Reactive Strategies

sensor space actuator space

Sequential Strategy

Reactive Strategy

sensors actuators

Real time operating system

Processes/threads

actuators

Real time operating system

ArbitrationTouch Turn Wander

Embedded Java

The leJOS API classes provide real time events,sensor events and threads:

TimerListener

SensorListener

Thread

Timer

a simple round robin 2ms time slice for threads of equal priority...

Runnable Non-Runnablesuspend()

resume()

yield()

Running

dispatch

suspend()

start()

stop(), orrun() returns

sleep()

Alive

Line following

A PID Controller For Lego Mindstorms Robots