IntermediateTopic 63 of 102Manufacturing, Robotics & Systems
Robot control
PID, computed torque and impedance control.
In depth
Joint-level PID with high-gain feedback, computed-torque (inverse dynamics) control, impedance/admittance control for interaction, force control, visual servoing and learning-based methods. Cascaded loops: current, velocity, position. Stability and robustness to payload variation are key.
Key points
- Gravity compensation
- Impedance: desired stiffness and damping
- Sample time 1 kHz
ExamplePolishing a surface needs force control to maintain constant contact pressure.
What is Robot control?
PID, computed torque and impedance control.
Why is it important to understand robot control?
Robot control turns planned motions into accurate movement, so the control design decides how well a robot follows its path.
What is computed torque control?
A method that uses the robot dynamic model to cancel nonlinear effects, so the joints behave like simple linear systems.
What is impedance control?
A control that makes the robot behave like a spring and damper to the environment, which is useful for safe contact with people or objects.
How is Robot control used in practice?
Typical applications include tuning PID loops on each axis of a Cartesian robot, using computed torque control for a fast arm with varying loads and designing an impedance controller so a robot yields when it touches a person.
What should I learn before Robot control?
Study "End effectors and grippers" first (topic 62 of 102 in Manufacturing, Robotics & Systems). It covers the groundwork this topic builds on.
What are the key points of Robot control?
Gravity compensation. Impedance: desired stiffness and damping. Sample time 1 kHz.
Can you give an example of Robot control?
Polishing a surface needs force control to maintain constant contact pressure.
What comes after Robot control?
The next topic is "Robot vision", which builds directly on this one.
How difficult is Robot control?
It is classed as Intermediate in Manufacturing, Robotics & Systems (topic 63 of 102). It is an intermediate topic. Work through the beginner topics in Manufacturing, Robotics & Systems first.