M03 - Controllers (Brains) in Autonomous Systems Flashcards
What is situatedness?
- existing in a complex, dynamic and unstructured environment that strongly affects the robot’s behavior
Explain the loop that generates behavior of robots.
- the robot determines the state of its actuators on the basis of the current and previous observations
- the action of the robot alters the robot/environmental relation and the environment itself
What is the sensory-motor coordination?
The ability of an agent to act so to ensure that it will later experience useful observation
i.e. sensory states enabling the robot to achieve its goals
What are the steps of a sensory-motor coordination?
actions performed by robot -> effects further observations -> determine next actions
Can you predict a dynamic system, even with a complete knowledge of the robot & environment?
No (that is why they are hard to design)
Why do we need controllers?
- real world is dynamic, unpredictable
- to make a decision to accomplish a task, the situated robots need a controller
- make decisions based on perceived sensory information to decide
What control models do we have?
- open loop control
- closed loop control
Explain the open loop control model.
- parameters of the algorithm are set in advance
- parameters do not change while the system runs
- the desired results are (often) not guaranteed
Explain the closed loop control model.
- data from sensors influence behavior
- system uses errors to generate actions (goal is to minimize error for desired state)
What control model do autonomous robots use?
closed loop control
Explain the open loop control through an example
e.g. microwave
- semi-autonomous
-needs user input
- if the timing is not correct given by user, you can burn meal
- the system does not know the desired output to adjust timing by itself
What two complementary kinematics do we have?
- forward kinematics
- inverse kinematics
Explain the forward kinematic.
Given a sequence of commands, what is the final position of the robot’s arms?
- easy to compute
Explain inverse kinematics.
Given a desired position of the robotic arm, what sequence of commands will bring it to that position
- hard to compute
- there can be one, multiple or no solution
What components are there in the closed-loop control system aka feedback control?
r: reference value
y: output
u: control value
e: error
Explain the reference value r in a feedback loop and give an example.
The specification of robot’s task.
e.g. the position of robot relative to a stack of shelves and the distance of gripper
Explain the output y in a feedback loop and give an example.
It is the actual state of the robot
e.g. the distance to an object