L3 CONTROL SUMMARY

Question 1

What are the principles of deliberative control? + examples of areas whare mostly used

Answer 1

Deliberative control is an old way to control systems. Its principle is Think hard, Act later!

Its phases are sensing, planning and acting. An important phase between sensing and acting is planning (thinking!) which involves very often searching for best solutions. This type of control needs an internal representation of the world, such as maps. Deliberative control is used for example in chess software or route planning in navigation systems.

Question 2

What are the principles of reactive control? + examples of areas whare mostly used

Answer 2

Reactive control is a controller algorithm with the principle: Don’t think, react!

Examples that use this algorithm are curtains and thermostat in smart homes, obstacle handling and landmark navigation in autonomous cars. Instead of a map, a reactive controller agent uses a collection of rules that couple actions to specific situations.

Question 3

What modules of a navigation system and their roles?

Answer 3

In automative navigation systems, the road infrastructure is usually represented using a directed valued graph. The main modules of a navigation system are self‐localization (positioning), route/path planning, map building, map interpretation, user guidance.

● the illumination table is given just as illustration, you do not have to memorize it

● open loop control (principle, block diagram, examples)

● feedback closed loop control (principle, block diagram, examples)

Open loop control only looks at its input signal in order to decide what to do. It does not take into account what is happening to its output

Example: smart curtains (light level outside, curtains), microwave (set minutes, food)

Question 4

How can a smart vehicle detect obstacles? sensors principles, you should be able to write some simple controllers in pseudocode

Answer 4

An ultrasound sensor is a ranging sensor, meaning that the sensor measures the distance to the object. Ultrasound sensors work with an underlying principle called echolocation, the ultrasound sensor sends out a sound beam and measures the time needed to receive the echo reflected by the object, called time of flight (ToF).
- Ultrasound sensors are cheap but not very accurate
- also the problem of specular reflection → if the beam hits a smooth surface at a shallow angle, then it is reflected outwards and not back to the emitter

+CODE

Light Detection And Ranging, or laser radar. This sensor uses laser light beams instead of sound. The laser beam is swept across the sensor’s field of view and makes an image of the surroundings the same way a sonar does.

A passive optosensor measures the ambient light intensity with a photosensitive element as sensing element.

An active optosensor has its own light source that shines on the object and it measures the reflected light and can be thus used as a color sensor.

• A transducer is a device that converts one physical quantity into another For example, a thermometer converts temperature into a dilation of mercury or alcohol column

● how to follow a black line? sensors, controllers in pseudocode