Core Robotics Concepts

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What is a robot made up of?

Your robot is made up of a few key components:

• Joints/Actuators: The motors of the robot that allow the links to move relative to each other.
• Links: The rigid plastic parts of the robot that are connected by joints.
• End effector: The last part of the robot that interacts with the environment (e.g., a gripper).
• Sensors: The robot’s eyes and ears. They allow the robot to perceive the world around it.
• Controller: The robot’s brain. It processes the sensor data and sends commands to the actuators.

The main challenge is coordinating all these components to perform specific tasks. How do we program the robot to move to a specific position or grasp an object?

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What is a policy?

A policy defines how the robot makes decisions and takes actions based on its environment. It is a function that maps the current state of the robot to an action. In concrete terms, it tells the robot what to do in a given situation.

For example, a policy for a robot vacuum cleaner might be:

• If the robot detects dirt, move towards it.
• If the robot detects a wall, turn left.

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Vocabulary

• State: The current configuration of the robot. This includes the positions of the joints, the orientation of the end effector, and any sensor readings.
• Action: The movement or command the robot executes in response to its current state.
• Reward: A numerical value assigned based on how well the robot’s action achieves its objective. The robot’s goal is to maximize this reward over time.
• Environment: The world in which the robot operates. This includes the objects in the environment, the robot itself, and any other agents.