Engine Speed Governor for Manual Transmission Take-Off
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current vehicle take-off strategies, particularly in vehicles with manual gearboxes and small engines, are challenging due to steep torque maps that lead to engine stalling or racing issues, making it difficult for drivers to smoothly accelerate from stationary positions, especially in traffic jams or during parking maneuvers.
Innovation Solution
Transforming the accelerator pedal depression into a speed setpoint, which is then regulated by a PID-type speed regulator to generate an engine torque setpoint, ensuring the engine speed remains stable and preventing stalling or racing, without requiring modifications to the engine components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a steep take-off torque map is used to prevent engine stalling, then the engine can generate sufficient torque for vehicle take-off, but the driver lacks progressiveness when depressing the accelerator pedal and the engine tends to rev up too much or stall
Solution Approach 1:
The patent introduces a clutch slip ratio as an intermediary parameter between the accelerator pedal position and the engine torque output. During take-off, the clutch slip ratio modulates the torque transmission, allowing the engine to operate at higher RPMs without directly transmitting excessive torque to the wheels. This mediator enables progressive driver control while maintaining sufficient engine power for take-off.
Solution Approach 2:
The patent dynamically adjusts the torque map based on clutch slip conditions. Instead of using a fixed steep torque map, the system modifies the torque output in real-time according to the clutch engagement state. This dynamic adjustment allows the engine torque to be progressive and controllable during take-off, preventing both stalling and excessive revving.
2Ease of operation
If a progressive non-take-off torque map is used for smooth acceleration, then the driver has better control during normal operation, but the engine does not generate sufficient torque for dynamic take-off
Solution Approach 1:
The patent implements a dynamic torque map that switches between progressive and steep characteristics based on vehicle speed and clutch engagement state. At low speeds during take-off, the map provides progressive torque for driver control. At higher speeds during normal operation, the map transitions to a steeper characteristic for dynamic acceleration, combining the benefits of both maps.
Solution Approach 2:
The patent segments the torque map into different regions based on vehicle operating conditions. The take-off phase uses one torque characteristic while the non-take-off phase uses another. This segmentation allows the system to optimize for either driver control or dynamic power delivery depending on the specific operating condition.
3Use of energy by moving object
If small engines are used to reduce consumption, then fuel efficiency is improved, but vehicle take-offs become difficult
Solution Approach 1:
The patent uses the clutch slip mechanism as an intermediary to amplify the effective torque delivery of small engines. By allowing controlled slip during take-off, the system enables small engines to deliver sufficient torque to the wheels without requiring the engine itself to produce excessive power, thus maintaining fuel efficiency while improving take-off performance.
Solution Approach 2:
The patent changes the operational parameters of the clutch system during take-off to optimize small engine performance. By adjusting clutch engagement characteristics and slip ratios, the system maximizes torque transmission efficiency, allowing small engines to achieve adequate take-off performance without increasing engine displacement or power output.
Data Source
Figure 1~2
Figure 3
AI summary
The method involves providing a speed setpoint (Wcons) with respect to a parameter selected among a depression angle of an accelerator pedal (1) of a vehicle and a depression speed of the pedal, to a support on the pedal, and transmitting the speed setpoint to a speed limiter. A torque setpoint (C) is provided via the limiter to a heat engine (4) such that the engine presents a speed (Wmes) equal to the speed setpoint. The speed setpoint is equal to sum of an idle speed of the vehicle and an intermediate speed value issued from a cartography that is function of depression of the pedal.