Powertrain Torque Feedback for Downhill Target Speed Control
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Solution Overview
Problem
Vehicles traveling downhill, especially when towing a trailer or hauling heavy loads, experience excessive brake applications due to uncontrollable acceleration, leading to undesirable driving conditions.
Innovation Solution
A powertrain torque control system that detects braking behavior to set a target speed and applies torque feedback to limit acceleration, maintaining the target speed while descending downhill.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the driver uses brakes to control vehicle speed while descending downgrade, then the vehicle speed can be reduced, but the number of brake applications increases and driving stability deteriorates
Solution Approach 1:
The patent replaces the mechanical braking system with a powertrain torque control system. The controller applies negative torque through the powertrain (engine or motor) to counteract gravity-induced acceleration on downgrades, substituting the need for repeated brake applications with a smoother torque-based speed control mechanism.
Solution Approach 2:
The system continuously monitors vehicle speed and acceleration through sensors, compares actual values with target values, and adjusts powertrain torque accordingly. This closed-loop feedback control maintains vehicle speed without requiring multiple brake interventions, improving driving stability.
2Speed
If the driver applies brakes frequently to maintain target speed on downhill, then speed control is achieved, but brake wear increases and energy is lost
Solution Approach 1:
The system converts the harmful effect of gravity-induced acceleration into a beneficial regenerative braking effect. By applying negative torque through the powertrain, the engine acts as a generator to recover energy that would otherwise be wasted as heat in the brakes, reducing both brake wear and energy loss.
Solution Approach 2:
Instead of continuous brake application, the system uses periodic torque adjustments through the powertrain control. The controller modulates powertrain torque in controlled intervals to maintain speed, replacing continuous brake engagement with intermittent torque management that reduces energy dissipation.
3Device complexity
If the vehicle allows natural acceleration on downgrade, then no powertrain intervention is needed, but the vehicle speed exceeds the target speed and brake applications increase
Solution Approach 1:
The system performs preliminary speed control by applying powertrain torque before the vehicle acceleration becomes excessive. The controller proactively manages torque to prevent speed from exceeding the target, avoiding the need for reactive brake applications and reducing overall system complexity.
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
Reduces the number of brake applications by controlling vehicle acceleration, enhancing downhill driving stability and comfort.
Implementation Method 1
The downhill speed control may include applying powertrain torque feedback to limit an acceleration of the vehicle to hold the target speed of the vehicle while descending downgrade
Data Source
AI summary
Systems and methods related to downhill target speed acceleration control are provided. A powertrain torque control system includes a logic device configured to detect a braking behavior to set a target speed of a vehicle to descend downgrade. The logic device is further configured to activate a downhill speed control of the vehicle based on the detected braking behavior. The downhill speed control may include applying powertrain torque feedback to limit an acceleration of the vehicle to hold the target speed of the vehicle while descending downgrade. Associated methods and vehicles are also provided.