Vehicle Control Circuits for Smooth Return to Cooperative Driving
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Solution Overview
Problem
Existing vehicle control devices fail to quickly return to cooperative driving mode after an abnormality is resolved, leading to potential discomfort for the driver due to motor torque fluctuations when certain conditions are not met.
Innovation Solution
A control device with a master-slave relationship between systems, where current command values are gradually adjusted to transition from independent to cooperative driving mode, using distribution and output gains to smooth the change and suppress torque fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the return permission condition is strictly enforced (including steering state determination), then the system stability is improved, but the return time from independent driving mode to cooperative driving mode is extended
Solution Approach 1:
The patent applies dynamics by making the return permission determination adaptive rather than static. The control device dynamically adjusts the return permission determination based on the absolute value of the difference between current command values. When the difference is within a predetermined threshold, the return permission is granted even if steering state conditions are not fully met, enabling faster transition while maintaining stability when differences are large.
2Loss of time
If the driving mode is quickly returned to cooperative driving mode by omitting return permission conditions, then the return time is reduced, but motor torque fluctuations occur causing driver discomfort
Solution Approach 1:
The patent implements feedback by continuously monitoring the absolute value of the difference between current command values from master and slave control circuits. This feedback mechanism determines whether return permission should be granted. When the difference exceeds a threshold, the system prevents return to cooperative mode, thereby avoiding torque fluctuations and driver discomfort while still enabling quick return when conditions are safe.
3Speed
If the current command values are not adjusted during mode transition, then the transition speed is improved, but the motor torque fluctuates rapidly causing driver discomfort
Solution Approach 1:
The patent applies preliminary action by adjusting the current command values before completing the mode transition. The control device modifies the current command values in advance during the transition from independent to cooperative driving mode, ensuring that torque fluctuations are suppressed before they can affect the driver. This preliminary adjustment maintains both transition speed and comfort.
Data Source
AI summary
A control device includes control circuits of a plurality of systems. When a transition condition is established, the control circuits of the systems make transition of a driving mode from a first driving mode to a second driving mode, and when a return condition is established in a state in which the driving mode has transitioned to the second driving mode, the control circuits of the systems make transition of the driving mode from the second driving mode to the first driving mode while gradually changing the current command values of the control circuits' own systems toward the current command values before the adjustment.