Indirect adaptive robot control

The theoretical issues linked to the development of indirect adaptive robot controllers are discussed, and some possible solutions are proposed. After a review of the prediction models used for robotic parameter estimation, a variety of parameter estimation methods are discussed under a common framework based on an exact solution approach. A novel indirect adaptive controller structure, which consists of a modified computed torque using parameters obtained from any of the estimators discussed, is presented. It is shown that a critical difficulty in using indirect adaptive control is the necessity to explicitly guarantee that the estimated inertia matrix remains positive definite in the course of adaptation, a requirement avoided by both the direct and the composite adaptive controllers. A practical solution to this difficulty is proposed. >

Authors

• Weiping Li
• Jean-Jacques E. Slotine

Keywords

• Programmable control
• Adaptive control
• Robot control
• Error correction
• Manipulator dynamics
• Convergence
• Tracking
• Torque control
• Nonlinear control systems
• Control systems
• Parameter Estimates
• Global Convergence
• Prediction Error
• Optimal Control
• Positive Constant
• Least Squares Estimation
• Equivalent Parameters
• Tracking Error
• Gain Matrix
• Exponential Stability
• Proof Of The Lemma
• Square Integrable
• Positive Definite
• Joint Torque
• Load Parameters
• Inertia Matrix
• Time-varying Factors
• Exponential Convergence
• Forgetting Factor
• Poles And Zeros
• Joint Acceleration
• Course Of Adaptation
• Gradient Approximation
• Inertial Parameters
• Persistent Excitation
• Estimation Performance
• Control Design
• Use Of Models