Steering Control Device Torque-Based Guarding for Systematic Errors
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Solution Overview
Problem
Existing steering control devices fail to effectively control synchronous motor torque when systematic errors, such as controller parameter abnormalities or logic errors, occur during feedback control.
Innovation Solution
A steering control device with a torque-based guarding processing circuit that limits the update amount of the control angle to prevent excessive deviations, using upper and lower limit guard values to maintain assist torque control even in the presence of systematic errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If feedback control is used to control steering torque to target torque, then torque control precision is improved, but systematic errors such as parameter abnormalities or logic errors cause inappropriate torque control
Solution Approach 1:
The patent implements feedback control by comparing the detected steering torque with the target torque and adjusting the control angle accordingly. The control angle manipulation processing circuit calculates the difference between detected torque and target torque, then manipulates the control angle to minimize this difference, achieving precise torque control through continuous feedback adjustment.
Solution Approach 2:
The patent applies preliminary action by setting guard values for the control angle update amount before systematic errors can cause significant deviations. The torque-based guarding processing circuit pre-establishes upper and lower limit guard values that restrict the control angle update amount, preventing excessive deviations even when systematic errors occur in the feedback control process.
2Speed
If the control angle update amount is allowed to vary freely, then the system can respond quickly to torque deviations, but systematic errors cause excessive deviations and loss of control
Solution Approach 1:
The patent applies dynamics by making the control angle update amount adaptive rather than fixed. The torque-based guarding processing circuit dynamically adjusts the update amount based on the detected steering torque, using torque-based guard values that allow larger updates when torque deviation is small and restrict updates when torque deviation is large, optimizing both response speed and stability.
Solution Approach 2:
The patent changes the parameter of control angle update amount based on the detected steering torque. The torque-based guarding processing circuit modifies the update amount parameter by comparing it with torque-based upper and lower limit guard values, ensuring the update amount remains within appropriate ranges corresponding to the current torque state, thus preventing excessive deviations while maintaining responsive control.
Data Source
AI summary
There is provided a steering control device that can control even when a systematic error has occurred. An update amount calculation processing circuit manipulates a control angle in accordance with an update amount in order to control steering torque, which is obtained by subjecting the magnitude of steering torque to a decrease correction by a threshold, to target torque through feedback control. The control angle is used to convert a current command value to a value in a fixed coordinate system or the like. The update amount is subjected to a guarding process in accordance with the steering torque by a torque-based guarding processing circuit, and determined as a final update amount for the control angle. The torque-based guarding processing circuit performs the guarding process on the update amount such that the update amount is in an allowable range that matches the steering torque.