Vehicle Speed Control with External Force Compensation
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Solution Overview
Problem
Existing vehicle speed control systems fail to adequately compensate for external forces such as gravity and terrain resistance, leading to inconsistent acceleration and deceleration, which can result in overshooting or undershooting of target speeds and decreased user confidence.
Innovation Solution
A method and system that detect external forces acting on the vehicle and adjust the rate of change of net torque applied to the wheels to compensate for these forces, ensuring consistent acceleration and deceleration by applying a predetermined gain to the torque components, thereby maintaining the target speed across varying terrains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the vehicle accelerates or decelerates to reach target set-speed in known speed control systems, then the vehicle speed control function is provided, but external forces (gravity, rolling resistance, drag) are not sufficiently compensated for, causing overshooting or undershooting of target speed and inconsistent acceleration
Solution Approach 1:
The system performs preliminary detection of external forces (gravity, rolling resistance, drag) acting on the vehicle before executing speed control commands. By detecting these forces in advance and compensating for them in the torque calculation, the system prevents overshooting or undershooting of target speed, thereby improving both reliability and acceleration consistency.
2Adaptability or versatility
If the vehicle traverses varying terrains with different external forces, then the vehicle can operate in diverse environments, but the acceleration or deceleration becomes inconsistent with user expectation and prescribed acceleration profile
Solution Approach 1:
The system continuously monitors external forces acting on the vehicle (gravity, rolling resistance, drag) and uses this feedback information to dynamically adjust the torque applied to the wheels. This closed-loop control ensures that the vehicle maintains consistent acceleration profiles across varying terrains, improving reliability while preserving terrain adaptability.
Solution Approach 2:
The system changes the torque parameter dynamically based on detected external forces. By adjusting the torque magnitude in response to varying terrain conditions, the system maintains consistent acceleration behavior across different environments, resolving the contradiction between adaptability and profile consistency.
3Force
If external forces act on the vehicle during speed control, then the vehicle experiences natural acceleration or deceleration effects, but the net torque applied to wheels does not compensate for these forces, leading to undesirable acceleration beyond expectation
Solution Approach 1:
The system applies a counter-torque to compensate for external forces acting on the vehicle. By calculating the magnitude of external forces (gravity, rolling resistance, drag) and applying an opposing torque through the powertrain, the system neutralizes their effect and maintains precise acceleration control, improving reliability while accounting for external force effects.
Data Source
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AI summary
A method for operating a speed control system of a vehicle is provided. The method comprises detecting an external force acting on the vehicle wherein the external force has an accelerating or decelerating effect on the vehicle. The method further comprises automatically adjusting a rate of change of at least one component of a net torque being applied to one or more wheels of the vehicle to compensate for the accelerating or decelerating effect of the external force on the vehicle. A system for controlling the speed of a vehicle comprising an electronic control unit configured to perform the above-described methodology is also provided.