Servomotor Control Device Rigidity Estimation
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Solution Overview
Problem
Existing servomotor control systems require full-closed feedback values from linear scales to estimate the rigidity of connection mechanisms, which is inconvenient and inefficient.
Innovation Solution
A servomotor control device that estimates the rigidity of the connection mechanism using only semi-closed feedback values from the servomotor encoder, with a motor control unit including a force acquisition section and a rigidity estimation section to calculate the rigidity based on position information and drive force, and optionally includes deterioration detection, storage, communication, and notification sections for monitoring and maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If full-closed feedback values from linear scales are used to estimate rigidity, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts the rigidity estimation function from the full-closed feedback system (linear scale) and implements it using only semi-closed feedback from the servomotor encoder. By taking out the linear scale requirement and using only the encoder's position information combined with drive force data, the system achieves rigidity measurement without increasing device complexity.
Solution Approach 2:
The patent introduces an intermediary calculation method that uses the relationship between drive force and position information from the encoder to estimate rigidity. Instead of directly measuring position with a linear scale, the system uses the encoder's semi-closed feedback as an intermediary to derive rigidity information through force-acquisition and calculation processes.
2Manufacturing precision
If linear scales are mounted to obtain full-closed feedback, then positioning accuracy is improved, but ease of operation deteriorates
Solution Approach 1:
The patent removes the linear scale component from the system while maintaining positioning accuracy through rigidity estimation. By extracting the requirement for full-closed feedback and replacing it with semi-closed feedback from the encoder combined with force-based rigidity calculation, the system becomes easier to operate without sacrificing positioning precision.
3Device complexity
If semi-closed feedback from encoder only is used, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent combines multiple data sources (encoder position information and drive force data) to create a composite measurement approach for rigidity estimation. By synthesizing semi-closed feedback with force acquisition and calculation, the system achieves accurate rigidity measurement without requiring the simpler encoder-only approach to be insufficient.
Solution Approach 2:
The patent implements a feedback mechanism where drive force information is acquired and used in conjunction with encoder position data to continuously estimate rigidity. This feedback loop compensates for the limitations of semi-closed feedback alone, maintaining measurement precision while keeping device complexity low.
Data Source
AI summary
A servomotor control device includes: a servomotor; a driven body that is driven by way of the servomotor; a connection mechanism that connects the servomotor and the driven body to transmit power of the servomotor to the driven body; and a motor control unit that controls the servomotor, in which the motor control unit includes: a force acquisition section that acquires a drive force acting on the driven body at a connection part between the connection mechanism and the driven body; and a rigidity estimation section that estimates a magnitude of rigidity of the connection mechanism, based on position information of the servomotor and a drive force acquired by the force acquisition section when causing the servomotor to rotate in a state mechanically fixing the driven body.