Automatic Mechanical Braking for Electric Vehicle Speed Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The electric propulsion system in vehicles may fail to maintain a desired speed under certain conditions, such as downhill driving or icy roads, necessitating a mechanical braking system that can be automatically applied to ensure speed control.
Innovation Solution
A mechanical braking system with four brake controllers, two for the front wheels and two for the rear wheels, is automatically activated by an alarm signal from the electric propulsion system, using a gain control circuit to ensure that brake signals for the front wheels are equal to or less than those for the rear wheels, thereby maintaining vehicle speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the electric propulsion system operates in retard mode to maintain desired speed, then energy efficiency is improved by using electric braking, but the system fails to maintain desired speed under certain conditions such as downhill driving or icy roads
Solution Approach 1:
The system dynamically switches between electric braking mode and mechanical braking mode based on real-time operating conditions. The controller monitors vehicle speed, desired speed, and road conditions to determine when to transition from electric propulsion system retard mode to mechanical braking system engagement, ensuring optimal performance across varying conditions.
Solution Approach 2:
The system changes the braking mechanism parameter from electric braking to mechanical braking based on detected operating conditions. When the electric propulsion system cannot maintain desired speed (detected via alarm signal), the system transitions to mechanical braking, effectively changing the braking parameter to suit the current operational requirements.
2Reliability
If manual mechanical braking is applied after alarm signal, then speed control can be achieved, but the driver must be aware of desired speed and apply braking appropriately, increasing operational complexity
Solution Approach 1:
The mechanical braking system operates automatically upon receipt of the alarm signal from the electric propulsion system. The controller self-manages the braking application without requiring driver intervention, eliminating the need for the driver to monitor desired speed and manually apply braking, thus reducing operational complexity while maintaining speed control reliability.
Solution Approach 2:
The system uses feedback from the alarm signal generated by the electric propulsion system to trigger automatic mechanical braking. The controller continuously monitors the alarm signal status and automatically adjusts mechanical braking application based on this feedback, creating a closed-loop control system that maintains speed without driver intervention.
3Speed
If brake signals for front wheels are not controlled relative to rear wheels, then braking response may be faster, but uneven braking distribution can cause vehicle instability or sliding
Solution Approach 1:
The gain control circuit applies different brake signal characteristics to front and rear wheels based on their specific roles in vehicle dynamics. The circuit ensures front wheel brake signals are controlled to be equal to or less than rear wheel brake signals, creating a localized quality difference in braking force distribution that maintains vehicle stability while achieving effective speed control.
Data Source
AI summary
A mechanical braking system is provided for a vehicle having an electric propulsion system which is utilized for retard speed regulation. While the retard speed regulation is normally performed via electric braking, in some conditions the electric braking is not able to maintain a desired speed for the vehicle. In this condition, upon receipt of a signal from the electric propulsion system, the mechanical braking system is automatically activated so as to maintain the vehicle at the desired speed.