Cruise Control Torque Integral Adjustment on Changing Road Grades
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Solution Overview
Problem
Existing vehicle control systems during cruise control mode experience unstable behavior due to delays in torque response to road gradient changes, particularly on high-gradient roads, leading to potential vehicle instability.
Innovation Solution
A vehicle control device with a controller that switches between normal and cruise control modes, using integral control to adjust torque command values based on road gradient changes, executing an integrated-value adjustment process when transitioning between road types to reduce torque deviation and stabilize vehicle speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If integral control is used to maintain vehicle speed at target speed, then vehicle speed stability is improved, but torque response delay occurs on high-gradient roads leading to unstable behavior
Solution Approach 1:
The controller predicts road gradient changes before they significantly affect vehicle speed and preemptively adjusts torque command values. By detecting gradients in advance and preparing torque adjustments beforehand, the system eliminates response delays while maintaining speed stability during cruise control mode.
Solution Approach 2:
The control system dynamically adapts torque command values based on real-time road gradient conditions. When uphill or downhill gradients are detected, the controller automatically modifies torque output to compensate for gravitational effects, ensuring both rapid response and stable speed maintenance without fixed delay.
2Stability of the object's composition
If torque is quickly adjusted in response to road gradient changes, then vehicle stability is improved, but torque deviation increases causing shocks and excessive acceleration or deceleration
Solution Approach 1:
The controller calculates and applies gradual torque adjustments that cushion against sudden gradient changes. By preparing compensatory torque values in advance and applying them smoothly, the system prevents shocks and excessive acceleration/deceleration while maintaining vehicle stability during road gradient transitions.
Solution Approach 2:
The control system applies periodic, incremental torque adjustments rather than single large changes. This rhythmic modulation of torque commands smooths out deviations, eliminating shocks while maintaining stable vehicle speed during cruise control operation on varying terrain.
Data Source
AI summary
A vehicle control device includes a controller configured to control operation of a driving motor that is to output a driving force for a vehicle. The controller is switchable between a normal mode of controlling acceleration/deceleration based on a driver's acceleration/deceleration operation, and a cruise control mode of maintaining the vehicle speed at a target speed without the acceleration/deceleration operation. The controller is configured to, during the cruise control mode, calculate a torque command value for the motor by using integral control based on an integrated value of a deviation between the vehicle speed and the target speed, and execute an integrated-value adjustment process if the controller determines that the vehicle entered a flat road or an uphill road from a downhill road or a downhill road from a flat road or an uphill road. The process adjusts the integrated value to reduce an absolute value of the integrated value.