Cascade Control Disturbance Feedforward for Steering
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Solution Overview
Problem
Conventional steering control systems struggle to effectively incorporate driver interventions into cascaded control structures, leading to reduced control performance and limited use of inner control circuits, as driver interventions are mistakenly compensated for rather than accepted as steering signals.
Innovation Solution
An evaluation device interconnects multiple control circuits to incorporate interference signals, determining model steering signals that account for driver interventions, allowing these to be integrated as steering signals within the control process, thereby improving guidance behavior without compromising stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If driver intervention is treated as interference signal in cascaded control structure, then control stability is maintained, but control performance is reduced and driver intention is not properly recognized
Solution Approach 1:
The patent converts the harmful effect of treating driver intervention as interference into a beneficial outcome by reclassifying it as a steering signal. The evaluation device determines that when a driver applies manual torque to the steering column, this should be interpreted as intentional steering input rather than disturbance, thereby improving control performance while maintaining stability through the cascaded control structure.
Solution Approach 2:
The patent inverts the conventional approach by not compensating for driver intervention as interference, but rather incorporating it as a legitimate steering signal. The evaluation device reverses the standard control logic where driver input would be counteracted, instead allowing it to flow through the control cascade to achieve the desired steering angle, thus resolving the contradiction between stability and performance.
2Ease of operation
If control circuit gain is reduced when driver intervention is detected, then driver intention can be implemented, but control performance is limited
Solution Approach 1:
The patent implements dynamic gain adjustment based on the evaluation of driver intervention. The control circuit continuously monitors steering column torque and dynamically modifies the control gain according to whether driver input is present and its magnitude. This allows the system to maintain high performance when appropriate while accommodating driver intentions, resolving the contradiction between ease of operation and control performance.
3Device complexity
If inner control circuit performance is limited, then cascade control structure is simpler, but outer control circuits with yaw rate control cannot be used to full extent
Solution Approach 1:
The patent applies preliminary action by having the evaluation device assess driver intervention before it reaches the inner control circuit. By determining the nature of the interference signal in advance and converting it to a steering signal, the system prepares the input for the cascaded control structure, enabling outer control circuits with yaw rate control to function effectively without requiring complex modifications to the inner circuit performance.
Data Source
AI summary
An evaluation device (10) for an interconnection of at least one first control circuit and one second control circuit for incorporating an interference signal (w), wherein the interconnection comprises at least one first controller (A) for regulating a first control variable (yA) on the basis of a first steering signal (sA) in the first control circuit, and at least one second controller (B) for regulating a second control variable (yB) on the basis of a second steering signal (sB) in the second control circuit, wherein the first steering signal (sA) of the first controller (A) comprises a second output signal (uB) of the second controller (B), comprising an input interface (11) for receiving an interference signal (2), wherein the evaluation device (10) is configured to determine at least one first model steering signal (wA) for the first controller (A) and a second model steering signal (wB) for the second controller (B) based on the interference signal (w), and at least one output interface (12) for incorporating the first model steering signal (wA) in the first steering signal (sA) and the second model steering signal (wB) in the second steering signal (sB) such that the first steering signal (sA) comprises a portion of the interference signal (w) and the second steering signal (sB) comprises a portion of the interference signal (w), in order to take into account the interference signal (w) as a steering signal when regulating a technological process.