Vehicle Vibration Damping Control Hunting Suppression
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Solution Overview
Problem
Existing vibration damping control systems face issues with prolonged inoperative periods and reoccurrence of hunting when returning to normal operation, leading to decreased frequency of vibration suppression.
Innovation Solution
A vibration damping control apparatus that calculates a correction torque to suppress vehicle body sprung vibrations, outputs a hunting time correction torque command when the amplitude exceeds a predetermined level, and returns to a normal correction torque command when the amplitude drops below the threshold, thereby preventing unnecessary elongation of inoperative time and suppressing hunting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the control gain is decreased when vibration amplitude exceeds a threshold for a predetermined time, then hunting is suppressed, but the inoperative time of vibration damping control is prolonged
Solution Approach 1:
The patent applies preliminary action by setting a return judgment time period before fully restoring normal control. When vibration amplitude drops below the threshold, the system waits for this predetermined time period to elapse before returning to normal control gain, preventing premature restoration that could cause hunting reoccurrence while avoiding excessive inoperative time
Solution Approach 2:
The system continuously monitors vibration amplitude and uses this feedback to dynamically adjust control gain. The feedback mechanism compares current vibration levels against thresholds and timing conditions, automatically restoring normal control when safe conditions are met, thus balancing hunting suppression with timely restoration of vibration damping functionality
2Reliability
If the vibration damping control is stopped for a longer period to prevent hunting reoccurrence, then hunting is suppressed, but the frequency of vibration suppressing control decreases
Solution Approach 1:
By establishing a return judgment time period as a preliminary condition before restoring normal control, the system prevents immediate restoration that would cause hunting. This timed approach ensures hunting suppression while minimizing the duration of reduced control frequency, thus maintaining productivity
3Loss of time
If the control gain is restored immediately after vibration amplitude drops below threshold, then the inoperative time is shortened, but hunting reoccurs
Solution Approach 1:
The patent implements preliminary action by requiring the return judgment time period to elapse before restoring normal control gain. This preliminary timing condition prevents premature restoration that would cause hunting reoccurrence, while still restoring control as quickly as safely possible once the time period expires
Data Source
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AI summary
A vehicular vibration damping control apparatus calculates a correction torque to suppress vehicle body sprung vibration. In outputting a correction torque command to a driving/braking torque producing device, the control apparatus outputs a hunting time correction torque command smaller than a normal time correction toque command when a state in which amplitude of the correction torque is greater than or equal to a predetermined amplitude continues for a predetermined time length, and thereafter to return an output of the correction torque command from the hunting time correction torque command to the normal time correction torque command if a state in which the amplitude of the correction torque is smaller than or equal to the predetermined amplitude continues for a first predetermined time length. The frequency of performing the vibration damping control is increased by suppressing occurrence of hunting at the time of return to the normal vibration damping control.