Backlash compensation using neural network

An adaptive neural network compensator for compensating backlash of a mechanical system, comprising:

• a filter in a feedforward path, the filter configured to determine a filtered tracking error signal;
• a neural network in the feedforward path, the neural network configured to compensate the backlash by estimating an inverse of the backlash and applying the inverse to an input of the mechanical system;
• and
• means for tuning the neural network so that the filtered tracking error signal of the compensator is uniformly ultimately bounded.

An adaptive neural network compensator for compensating backlash of a mechanical system, comprising:

• a feedforward path;
• a proportional derivation tracking loop comprising a proportional derivative path in the feedforward path;
• a neural network in the feedforward path;
• and
• a nonlinear estimate feedback loop coupled to the feedforward path.

A method of adaptively compensating backlash in a mechanical system, comprising:

• estimating an inverse of the backlash using a neural network in a feedforward path;
• taking a filtered derivative of a tracking error signal of the compensator using a filter in the feedforward path to form a filtered tracking error signal;
• adjusting weights of the neural network as a function of the filtered tracking error signal using a Hebbian tuning algorithm to achieve closed loop stability;
• and
• applying the inverse to an input of the mechanical system to compensate the backlash.