Vehicle Motor Torque Control for Brake Failure Securing
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Solution Overview
Problem
Existing vehicle systems fail to optimally secure a vehicle at a stop when there is a loss of friction braking, particularly on hills or grades, where the vehicle may roll or not be properly held.
Innovation Solution
A method and system utilizing a processor to determine a loss in friction braking and provide propulsion torque from the vehicle's motor to secure the vehicle, including determining if the vehicle is stopped, communicating with the braking system, and shifting the park system to a park gear as necessary, with the ability to override automated controls and adjust torque based on rolling direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If friction brakes are used to secure the vehicle at a stop, then the vehicle can be held stationary, but the securing function fails when friction brake communication is lost
Solution Approach 1:
The motor serves as an intermediary component to provide backup securing function when the primary friction brake system fails. The motor provides propulsion torque to compensate for lost brake function, acting as a mediator between the control system and the vehicle's motion control needs.
Solution Approach 2:
The system changes the operational parameters of the motor from its normal propulsion function to a securing function by applying controlled propulsion torque in reverse or holding mode. This parameter change allows the motor to perform the securing function temporarily until the vehicle can be parked.
2Reliability
If the motor provides propulsion torque to secure the vehicle, then the vehicle remains stationary on slopes, but energy is consumed continuously
Solution Approach 1:
The motor torque application is dynamic rather than static - the motor provides torque only when needed (when brake failure is detected and vehicle speed is zero) and stops when the vehicle is secured in park gear. This dynamic operation reduces energy consumption compared to continuous torque application.
Solution Approach 2:
The system performs preliminary detection of brake system communication status and proactively engages the motor to provide securing torque before the vehicle can roll. This preliminary action prevents the need for higher corrective torque later, reducing overall energy consumption.
3Speed
If automated control actions are implemented for vehicle securing, then response time is reduced, but driver override capability is limited
Solution Approach 1:
The system incorporates feedback by continuously monitoring vehicle speed, park gear status, and driver inputs. When the driver attempts to accelerate or the vehicle speed becomes non-zero, the system receives feedback and automatically disengages the securing torque, providing both automated response and driver flexibility.
Solution Approach 2:
The automated securing system serves itself by automatically detecting brake failure, engaging motor torque, monitoring vehicle status, and disengaging when park gear is engaged - all without requiring driver intervention. The system only requires driver input when override conditions are met, balancing automation with control flexibility.
Data Source
AI summary
Methods and systems are for securing a vehicle. In an exemplary embodiment, the vehicle includes a body, a drive system, a braking system, and a processor. The drive system is configured to generate movement of the body, and includes a motor. The braking system includes friction brakes that provide friction braking. The processor is disposed onboard the vehicle, coupled to the motor, and is configured to at least facilitate: determining that a loss in friction braking has occurred while the vehicle is being stopped; and providing instructions to the motor for providing propulsion torque, thereby securing the vehicle at a stop, when it is determined that the loss in friction braking has occurred; wherein the motor is further configured to execute the instructions provided by the processor for providing the propulsion torque.