Vehicle Speed Control via Pitch Rate Torque Adjustment
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Solution Overview
Problem
Conventional vehicle speed control systems are ineffective in extreme terrain conditions and low-speed situations, leading to discomfort and potential vehicle damage due to abrupt acceleration and deceleration, and are often disabled by slip detection, which compromises control.
Innovation Solution
A vehicle control system that receives a pitch rate signal and adjusts torque applied to wheels based on terrain type, reducing torque during steep descents and applying braking to maintain stability and comfort, while continuing to manage speed even with wheel slip detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cruise control systems are used to maintain vehicle speed, then speed stability is improved on highways, but the system becomes ineffective and is automatically disabled in low-speed and extreme terrain conditions
Solution Approach 1:
The system dynamically adjusts the torque applied to wheels based on real-time pitch rate detection and terrain type identification. The torque adjustment is not fixed but varies continuously according to the vehicle's pitching motion and the detected terrain characteristics, enabling effective operation across diverse conditions from highways to extreme off-road environments
Solution Approach 2:
The system changes operational parameters (torque magnitude, braking force) based on detected pitch rate thresholds and terrain type. By monitoring pitch rate and comparing it against terrain-specific thresholds, the system automatically adjusts control parameters to maintain effectiveness across varying speed ranges and terrain conditions without automatic disablement
2Reliability
If torque is increased to maintain speed on steep gradients, then speed maintenance is improved, but abrupt acceleration and deceleration cause discomfort and potential vehicle damage
Solution Approach 1:
The system applies preliminary counteracting torque adjustments when pitch rate exceeds thresholds indicating upcoming steep gradients. By detecting the pitch motion before the vehicle completes the gradient transition, the system pre-adjusts torque to oppose the impending abrupt acceleration or deceleration, reducing harmful effects while maintaining speed control
Solution Approach 2:
The system continuously monitors pitch rate from sensors and uses this feedback to adjust torque in real-time. The closed-loop control compares detected pitch rate against thresholds and automatically modulates torque application to counteract abrupt speed changes, thereby maintaining speed stability while reducing discomfort and vehicle stress
Data Source
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AI summary
A vehicle control system for a vehicle having a plurality of wheels, the vehicle speed control system being operable to receive an input signal corresponding to a rate of change of an angle of pitch of the vehicle, pitch rate, the system being operable to command a change in an amount of torque applied to at least one of the plurality of wheels in dependence on the pitch rate.