5. Robot Control: PID Control and Trajectory Planning

Learning Objectives Explain that a robot needs a plan (trajectory) to get from a start to a finish point. Define 'setpoint' and 'error' in the context of robot movement. Describe the 'P' (Proportional) part of PID control using a simple analogy. Describe the 'D' (Derivative) part of PID control using a simple analogy. Map out a simple grid-based path for a robot that avoids an obstacle. Calculate the 'error' for a robot trying to follow a line. Have you ever wondered how a self-driving car stays perfectly in its lane or how a robot arm can grab an object so precisely? 🤖 Let's learn its secrets! Today, we'll explore two big ideas that make robots smart. First, we'll learn how robots plan their routes, called T...

TermDefinitionExample Trajectory PlanningCreating a step-by-step path for a robot to follow, like drawing a route on a map before you start a trip.A robot vacuum cleaner plans a path to cover the whole living room floor without bumping into the sofa. WaypointA specific spot or point along a robot's planned path. It's like a checkpoint in a video game.To get to the kitchen, a robot's waypoints might be: 1. End of the hallway, 2. Turn right, 3. In front of the fridge. PID ControlA method a robot uses to continuously check its work and fix mistakes. It helps the robot stay on its planned path, even if it gets bumped.A robot trying to follow a black line uses PID control to quickly turn back towards the line whenever its wheels drift off. SetpointThe target value or goal the ro...

The 'P' Rule (Proportional) Correction = P_Constant * Error This is the main rule for fixing mistakes. The bigger the error, the bigger the correction. If your robot is far from the line, it makes a big turn. If it's only a little bit off, it makes a small turn. The 'D' Rule (Derivative) Correction = D_Constant * (Change in Error) This rule helps prevent overshooting the target. It looks at how fast the error is changing. If the robot is rushing back to the line very quickly, this rule tells it to slow down its turn so it doesn't fly right past it. The Trajectory Plan Path = [Waypoint1, Waypoint2, Waypoint3, ...] A robot's path is stored as a list of waypoints. The robot's code uses a loop to go through the list, moving from on...