Machine tool, machine tool control system, and machine tool control method
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Solution Overview
Problem
Existing machine tool control systems experience low object moving accuracy due to reverse responses generated by friction compensation.
Innovation Solution
A machine tool system comprising a feed driver, a feedback controller, a friction compensator, and a reverse response reducer, where the friction compensator adds a friction compensation value to the command input for the feed driver, and the reverse response reducer uses the state variable of the feedback controller to minimize the reverse response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If friction compensation value is added to command value to compensate for rolling friction, then friction compensation accuracy is improved, but reverse response is generated causing deterioration in object moving accuracy
Solution Approach 1:
The friction compensation value is added in advance to the command value before the actual movement occurs. This preliminary compensation addresses the friction force that will act during movement, allowing the system to pre-correct for friction effects and reduce the generation of reverse responses during direction changes
Solution Approach 2:
The state variable from the feedback controller is utilized by the reverse response reducer to detect and compensate for reverse responses. The feedback mechanism continuously monitors the system state and adjusts the command value to counteract the harmful reverse response while maintaining friction compensation benefits
2Reliability
If friction compensation is applied to improve movement control, then friction effects are compensated, but reverse response is generated reducing overall control accuracy
Solution Approach 1:
The control system is divided into separate functional components: a friction compensator that handles friction compensation and a reverse response reducer that handles reverse response suppression. This segmentation allows each component to address its specific function independently, maintaining the benefits of friction compensation while eliminating the harmful reverse response effects
Solution Approach 2:
The reverse response reducer acts as an intermediary between the friction compensator and the feed driver. It receives the command value with friction compensation, processes it through the state variable feedback, and outputs a corrected command value that has had the reverse response component removed, thus mediating between friction compensation and accurate movement control
Data Source
AI summary
To accurately perform movement control of a moving body, a machine tool includes a feed driver that moves a moving body in the machine tool, a feedback controller that feedback-controls the feed driver in accordance with a state variable, a friction compensator that, to compensate for rolling friction that occurs in the feed driver, adds, in advance, a friction compensation value obtained from measurement data of rolling friction or a friction compensation value calculated using a rolling friction model to a command value to be input to the feed driver, and a reverse response reducer that reduces, using the state variable of the feedback controller, a reverse response that occurs due to addition of the friction compensation value.