Computed Torque Control

Definition

Computed torque control is a method used in robotics to manage the dynamic behavior of a system by calculating the required joint torques based on desired trajectories and the robot's dynamics. This technique combines feedforward control, which anticipates the necessary actions to achieve desired states, with feedback control to correct for any deviations. By leveraging knowledge of the system dynamics, computed torque control can enhance performance in tracking tasks and improve stability.

5 Must Know Facts For Your Next Test

1. Computed torque control requires an accurate dynamic model of the robot to ensure that the calculated torques correspond to the actual physical behavior of the system.
2. The method can effectively reduce the effects of disturbances or changes in system parameters by adjusting the torques in real-time based on feedback.
3. Computed torque control can be particularly beneficial for nonlinear systems, allowing them to achieve smoother and more precise motion.
4. The approach involves using both feedforward terms to counteract known dynamics and feedback terms to correct errors from unmodeled dynamics or disturbances.
5. This technique is widely used in applications requiring high precision, such as robotic arms in manufacturing and surgical robots.

Review Questions

• How does computed torque control integrate both feedforward and feedback mechanisms to manage a robotic system's motion?
  • Computed torque control integrates feedforward and feedback mechanisms by first calculating the necessary joint torques based on the dynamic model of the robot for a given trajectory. The feedforward component anticipates the required actions to achieve this trajectory, while the feedback component continuously adjusts these actions by measuring any discrepancies between the desired and actual states. This combination ensures that the robot can correct errors in real time, improving accuracy and stability during operation.
• Discuss the importance of having an accurate dynamic model when implementing computed torque control in robotics.
  • Having an accurate dynamic model is crucial when implementing computed torque control because it directly influences how well the calculated torques align with the robot's actual behavior. If the model is inaccurate, the feedforward calculations will be off, leading to poor performance and potentially unstable motions. Therefore, a precise model allows for effective prediction of required joint torques and ensures that feedback mechanisms can adequately compensate for any errors or disturbances, resulting in smoother operations.
• Evaluate how computed torque control can enhance the performance of nonlinear robotic systems compared to linear control strategies.
  • Computed torque control enhances the performance of nonlinear robotic systems by taking into account their unique dynamic characteristics, which often cannot be accurately represented by linear models. Unlike linear control strategies that may struggle with stability and precision in complex maneuvers, computed torque control utilizes both feedforward and feedback adjustments tailored to each specific task. This adaptability enables robots to handle varying conditions more effectively, ensuring consistent performance across diverse applications such as assembly lines or precision surgical tasks.

Related terms

Dynamic Model: A mathematical representation that describes how a robotic system behaves dynamically, including the forces and torques acting on it.

Feedback Control: A control strategy that adjusts system inputs based on the difference between desired and actual outputs to maintain stability and improve performance.

Trajectory Planning: The process of determining a desired path or series of positions that a robotic system should follow over time.