case study 4
TRANSCRIPT
Desired features of Mobile Robotics Architecture
Dr Reeja S RProfessorCSE Dept.SJEC, Vamanjoor,
Mangalore
Desired features of Mobile Robotics Architecture1. Supports deliberate and reactive behavior. (ex: collect
a rock sample) (ex: avoid an obstacle)
2. Allows uncertainty and unpredictability of environment. (such as contradictory sensor readings).
3. System must consider possible dangerous operations by Robot and in its environment (Ex: reduced power supply, dangerous vapors, unexpectedly opening doors of hazardous materials, etc)
4. The system must give the designer flexibility of experimentation and reconfiguration (mission’s change/requirement changes)
Solution #3: Implicit Invocation
Implicit invocation using exception handler, wiretapping and monitors
REQ #1:Supports Deliberate and reactive behavior
Deliberate : Task trees Reactive: exceptions, wiretapping and monitors
REQ #2:Should operate with incomplete and unreliable info
Create tentative task trees which are then modified by exception handlers when exceptional event occurs.
REQ #3:Account for danger Exception, wiretapping and monitors
address needs for performance, safety and fault tolerance
REQ #4:Design for flexibility (experimentation and reconfiguration)
For dynamic Reconfiguration, It is often sufficient to register new handlers, exceptions, wiretaps, or monitors with central server; no existing components are affected.
Solution #4: Blackboard
•The “captain”, the overall supervisor.
•The “map navigator”, the high level path planner.
•The “lookout”, a module that monitors the environment for landmarks.
•The “pilot”, the low level path planner and motor controller.
•The perception subsystem, the modules that accept the raw input from multiple sensors and integrate it into a coherent interpretation.
REQ #1:Deliberate and reactive behavior
Achieved using blackboard
REQ #2:Should operate with incomplete and unreliable info
The blackboard acts as a means of resolving uncertainties.
REQ #3:Account for danger Exception handling, wiretapping,
monitors can be used for certain signs of problematic situations
REQ #4:Design for flexibility (experimentation and reconfiguration)
Supports concurrencySeparates senders from receivers
Cruise Control System
Case Study #4
Cruise control- problem statement
Whenever the system is active, determine the desired speed, and control the engine throttle setting to maintain that speed.
Block diagram for cruise control
Booch’s OOD for cruise control
Process control view of cruise control
The cruise control system is supposed to maintain constant speed in an automobile despite variations in terrain, vehicle load, air resistance, fuel quality, etc.