Lecture 1 - Introduction

Question 1

What is a robot (4)?

Answer 1

A robot is an autonomous system (1) which exists in the physical world (2, embodiment), can sense its environment (3, situated), and can act on it to achieve goals (4).

Question 2

Autonomous

Answer 2

Acting, based on its own decisions, and not controlled by a human

Question 3

Teleoperated

Answer 3

Opposite to autonomous: externally controlled by humans

Question 4

Autonomous System (2)

Answer 4

Capable to maintain itself (1) in the outside world and to adapt and react differently (2) to the changing environment (extreme case learning mechanism).

Question 5

Embodied

Answer 5

a body, being able to act in the world

Question 6

Situated

Answer 6

being able to perceive the world

Question 7

Sensors (2) and Actuators (2) of Tortoises (early robots)

Answer 7

Sensors: Light and touch
Actuators: Forwards/Backwards and Steering.

Question 8

Braitenberg Vehicle 2a Fear

Answer 8

Straight, excitatory connection

Avoids light source and moves slower when further away

Question 9

Braitenberg Vehicle 2b Aggression

Answer 9

Crossed, excitatory connection

Approaching the source, moving faster when approaching.

Question 10

Frame-of-reference problem

Answer 10

The observer assigns a motivation to the agent, which is not the case.

Question 11

Example Frame-of-reference problem:

3 aggression vehicles, two with lights

Answer 11

Emergent behavior: When two agents are stuck against the wall, the third helps.
Actual behavior: The third agent is strongly attracted by the two lights of the stuck agents.

Question 12

Braitenberg Vehicle 3a ‘Love’

Answer 12

Straight, inhibitory connections

Approaches light source and moves slower when approaching it.

Question 13

Braitenberg Vehicle 3b ‘Explorer’

Answer 13

Crossed, inhibitory connections

Avoids light source and moves slower close to it.

Question 14

Braitenberg Vehicle 3c

Answer 14

Multi-sensorial with sensors for different qualities with varied excitatory, inhibitory, crossed or non-crossed connections.
Attracted by light, but turns away when close as it avoids obstacles.
-> different behavior without action selection mechanism.

Question 15

Braitenberg Vehicle 4 ‘Values and Special Tastes’-

Answer 15

Has non-linear activation function

-> increase in signal does not produce proportional in- or decrease in motor speed (it is non-linear)

Question 16

Braitenberg Vehicle 4a

Answer 16

Continuous but non-linear activation function.
Behavior: 1. Approaching light source (moving faster when closer)
2. At certain point, moving slower and turning from light source.

Question 17

Braitenberg Vehicle 4b

Answer 17

Discontinuous activation function, e.g. has a threshold

-> Agent sits still and suddenly starts to operate

Question 18

What do Braitenberg Vehicles 1-4 have in common (4)?

Answer 18

1. Purely reactive systems
2. No learning involved, no history.
3. Behavior is complex and hard to predict (especially with more sensors)
4. Limited level of autonomy.

Question 19

Braitenberg Vehicle 5 ‘Logic’

Answer 19

Threshold devices with logical Nodes which includes a hidden layer

Question 20

Recurrent logical connections equal to what?

Answer 20

Memory

Question 21

Segmentation of behavior (example vehicle 3c)

Answer 21

Observers segment behavior: first turning to light, then action of turning away.
Actual behavior: result of the internal process in interaction with environment. There is no action selection!

Question 22

Downhill invention (1) + Uphill analysis (2)
-> Which approach do they support (3)?

Answer 22

(1) Easy to build vehicles and increase complexity
(2) Difficult to understand why the robot exhibits certain behavior
(3) Supports synthetic approach (“Understanding by building”).

Question 23

What does complexity of behavior depend on (2)?

Answer 23

(1) Complexity of robot

(2) Complexity of world

Question 24

Simulated robots

(1) advantages
(2) focus on

Answer 24

(1)
- No hardware problems
- Simple observations
(2)
Collective behavior

Question 25

Reynold’s Boids

• Rules (3)
• > leads to

Answer 25

(1) Close: Don’t collide
(2) Middle: Same direction
(3) Far away: group!
- > leads to realistic group behavior

Question 26

Boids, tortoises and Braitenberg vehicles mimic biological creatures and therefore are…
+ What kind of control do they have?

Answer 26

Biomimetic robots

+They have reactive control

Question 27

Built in reflexes leads to behavior that is not built in. This is called:

Answer 27

Emergent behavior.

Question 28

Photophilic

Answer 28

“loving light” - some of the Braitenberg vehicles

Question 29

Photophobic

Answer 29

“afraid of light” - Braitenberg

Question 30

Which fields did robots grow out of (3)?

Answer 30

Control theory (mathematics of controlling machines), cybernetics (integration of sensing, action, and environment), and AI (mechanisms for planning and reasoning).

Question 31

(4) Main components of a robot

Answer 31

1. A physical body (to exist)
2. Sensors (to perceive environment)
3. Effectors and actuators (to take actions)
4. A controller (to be autonomous)

Question 32

State space

+ example for discrete and continuous

Answer 32

All possibles states a systems can be in.
Ex.:
1. The discrete Light switch has two discrete states (on or off)
2. The dimmable light switch is continuous.

Question 33

Representation / Internal model

Answer 33

The internal state used to remember information about the world (e.g. path through a maze).

Question 34

Sensor/perceptual space

Answer 34

Space of all possible sensory readings

Question 35

Effectors

Answer 35

Enables robot to take action. Similar to legs, wings or other body parts. They need underlying mechanisms (actuators) to work.

Question 36

Actuators

Answer 36

Do the actual work and enable action. Similar to muscles.

Question 37

Effectors and actuators are used for (2) main activities…

Answer 37

1. Locomotion: moving around

2. Manipulation: handling objects

Question 38

2 major subfields of robotics

1. Mobile robotics

Answer 38

Concerned with robots that move around mostly on the ground but also in the air and under water.

Question 39

2 major subfields of robotics

2. Manipulator robotics

Answer 39

Robotic arms of various types

Question 40

Controllers

Answer 40

provide the hardware and/or software that makes the robot autonomous by using the sensor inputs and any other information (memory) to decide what to do.