Servomotor Control Filter for Two-Inertial Systems
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Solution Overview
Problem
The existing control methods for servomotors in robot arms, such as those described in Non-patent Literature 1, are not versatile and have complex implementations due to higher order numerators compared to denominators in their filters, which complicate the conversion of disturbances into driving forces.
Innovation Solution
A control system and method that utilize a filter with equal order numerators and denominators, including inertia on both the driving and load sides, to estimate disturbances and convert them into driving forces, allowing for versatile and easily implementable feedback control in a two-inertial system model.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a filter with higher order numerator than denominator is used to convert disturbance into input torque, then the resonance-ratio control effect is achieved, but the implementation becomes complicated and versatility is reduced
Solution Approach 1:
The patent changes the parameters of the filter by ensuring the order of the numerator equals the order of the denominator, and specifically designing the numerator to include driving side inertia while the denominator includes load side inertia. This parameter adjustment maintains the resonance-ratio control effect while simplifying the filter structure and improving implementation ease and versatility.
2Reliability
If a filter with higher order numerator than denominator is used, then the resonance-ratio control effect is achieved, but the filter is not versatile
Solution Approach 1:
The patent modifies the filter parameters by setting equal orders for numerator and denominator polynomials, with the numerator containing driving side inertia and the denominator containing load side inertia. This parameter configuration maintains the essential resonance-ratio control functionality while making the filter applicable to broader control scenarios, thereby improving versatility.
3Device complexity
If a filter with equal order numerator and denominator is used, then implementation is simplified and versatility is improved, but the resonance-ratio control effect may be compromised
Solution Approach 1:
The patent carefully selects specific parameters for the equal-order filter: the numerator includes driving side inertia and the denominator includes load side inertia. This specific parameter selection ensures that the simplified filter structure still achieves the desired resonance-ratio control effect, resolving the contradiction between simplicity and effectiveness.
Data Source
AI summary
A control system according to an embodiment includes a motor configured to drive a link, a first sensor configured to detect information about the driving by the motor or information about a relation between the driving means and the load member as first sensor information, a second sensor configured to detect information about a displacement of the link as second sensor information, and a control unit configured to perform feedback control of the driving means so as to follow a command value in a two-inertial system model including an inertial system on a load side and an inertial system on a driving side. The control unit includes a disturbance observer configured to estimate a disturbance, and a filter configured to convert an estimated value of the disturbance into a driving force of the motor.