6 Robotics
What Is Robotics?
Robotics is an interdisciplinary field that integrates:
- Mechanics
- Electronics
- Control
- Computation
- Artificial Intelligence
Basic Components of a Robot
Mechanical Structure
- Links and joints form the robot body
- Determines degrees of freedom (DoF)
Actuators
- Motors (DC, servo, stepper)
- Convert electrical energy into motion
Sensors
- Proprioceptive: encoders, IMU
- Exteroceptive: camera, LiDAR, force sensors
Controller / Computer
- Embedded systems or onboard computers
- Executes control and planning algorithms
Kinematics
Forward Kinematics
- Computes end-effector pose from joint angles
Inverse Kinematics
- Computes joint angles from desired end-effector pose
- May have multiple or no solutions
Dynamics
- Models forces and torques required for motion
- Includes mass, inertia, gravity, friction
Control in Robotics
Feedback Control
- Uses sensor measurements to correct errors
- Common example: PID control
Trajectory Tracking
-
Follow a time-parameterized path
-
Balance accuracy and stability
Perception
- Extract information from sensor data
- Tasks include:
- Object detection
- Localization
- Mapping
Motion Planning
Planning Problem
- Find a collision-free path from start to goal
Common Planning Methods
- Grid-based search
- Sampling-based methods (RRT, PRM)
Learning-Based Robotics
Motivation
- Classical models are inaccurate or incomplete
- Learning improves adaptability
Reinforcement Learning in Robotics
- Learn control policies via trial and error
- Interaction with environment
- Reward-driven optimization
Simulation vs. Real World
Simulation
- Faster and safer
- Used for training and testing
Sim-to-Real Gap
- Physical discrepancies between simulation and reality
- Techniques: domain randomization