Vehicle Speed Control System for Off-Road Traction
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Solution Overview
Problem
Existing vehicle speed control systems are ineffective in congested traffic conditions and off-road environments due to minimum speed requirements, wheel slip events, and inability to maintain progress in varying terrains, leading to increased driver workload and reduced vehicle composure.
Innovation Solution
A system that automatically controls vehicle speed by applying brakes to wheels with lower traction and engaging cross-axle locking mechanisms to maintain target speed and reduce wheel slip, using sensors to monitor wheel speeds, surface friction, and steering angles to optimize resistance and traction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a minimum speed requirement is imposed on cruise control systems to reduce the likelihood of low speed collision, then safety is improved, but the system becomes ineffective in congested traffic conditions and off-road environments where low speed operation is necessary
Solution Approach 1:
The patent implements dynamic speed threshold adjustment where the minimum speed threshold is not fixed but adapts based on detected driving conditions. The system monitors wheel slip events and terrain characteristics, automatically lowering the speed threshold when off-road conditions or congested traffic are detected, thereby maintaining safety while enabling effective operation in previously restricted conditions.
Solution Approach 2:
The system changes the parameter of minimum speed threshold based on operating conditions. By detecting wheel slip events and terrain type, the system dynamically adjusts the speed parameter at which cruise control becomes active, allowing it to operate effectively in congested traffic and off-road environments while maintaining safety in normal conditions.
2Reliability
If cruise control systems are automatically disabled when wheel slip events are detected to maintain safety, then collision risk is reduced, but the system becomes ineffective in off-road conditions where wheel slip is common and progress maintenance is critical
Solution Approach 1:
The system dynamically adjusts its response to wheel slip events based on the detected terrain type. In off-road conditions, the system recognizes that wheel slip is normal and expected, so it maintains cruise control operation despite slip events. In contrast, on paved roads, wheel slip triggers system disablement to prevent unsafe operation.
Solution Approach 2:
The system changes the parameter of wheel slip tolerance based on terrain detection. When off-road terrain is detected, the system increases the acceptable level of wheel slip, allowing cruise control to remain active. This enables the system to maintain progress in off-road conditions while still responding appropriately to dangerous slip events on paved surfaces.
3Loss of energy
If traditional cruise control systems maintain vehicle speed by coasting after accelerator release, then fuel efficiency is improved, but the system cannot maintain progress in off-road conditions where continuous traction control is necessary
Solution Approach 1:
The system dynamically switches between coasting and active torque application based on terrain type and wheel slip detection. In normal road conditions, the system allows coasting for fuel efficiency. In off-road conditions, it maintains active torque control to ensure continuous progress, automatically adapting to the operational requirements of different terrains.
Solution Approach 2:
The system changes the parameter of engine torque application based on detected conditions. In off-road mode, the system maintains positive torque even when the accelerator is released, preventing vehicle stall and ensuring progress. In normal conditions, it reduces torque to enable coasting and improve fuel efficiency.
4Reliability
If cross-axle locking mechanisms are engaged to prevent wheel slip and maintain traction, then vehicle composure and traction are improved, but the mechanism increases resistance to wheel rotation which can affect vehicle speed and energy consumption
Solution Approach 1:
The system dynamically engages and disengages the cross-axle locking mechanism based on real-time detection of wheel slip events and terrain conditions. The mechanism is activated only when wheel slip is detected, providing traction assistance precisely when needed, and disengaged when traction is sufficient, minimizing energy consumption from continuous engagement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances vehicle composure and reduces driver workload by maintaining target speed in varying conditions, preventing wheel slip, and improving traction, especially in off-road and congested environments.
Implementation Method 1
apply a brake to a wheel of an axle to reduce a difference in speed between respective wheels of said axle
Implementation Method 2
controlling cross-axle locking means of an axle of the vehicle to cause an increase in resistance to relative rotation of wheels of the axle
Data Source
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AI summary
The invention relates to an automatic speed control. In line with the invention, the speed control remains active even if wheel slip is detected. To ensure traction, a differential (135,137) may be locked. As alternative or in addition, wheel brakes (114B, 115B) may be applied. The automatic speed control is maintained. The invention finds use in offroad drive.