Gear Shift Detection via Motor Load Torque Calculation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for detecting shifting operations in vehicles with engine and pedal power, such as using torque sensors or multiple sensor types, are costly and prone to false detections due to engine speed changes from various causes.
Innovation Solution
Calculating engine load torque, which is derived from the inherent motor torque and engine speed, using existing sensors like current sensors, to recognize shifting processes without additional hardware, and adjusting threshold values based on acceleration signals to differentiate between shifting and terrain-related fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If torque sensors are used to detect gear shifts, then detection reliability is improved, but device cost increases significantly
Solution Approach 1:
The system uses existing sensors (current sensor, speed sensor) that are already present in the motor controller to detect gear shifts. The control unit calculates motor load torque from these existing measurements without requiring additional torque sensors, making the system self-sufficient and avoiding extra costs.
Solution Approach 2:
The invention uses motor load torque as an intermediary parameter to detect gear shifts. Instead of directly measuring torque with expensive sensors, the system calculates load torque from the relationship between motor speed and inherent torque, using this intermediate value to infer gear shift events.
2Device complexity
If engine speed changes are used to detect gear shifts, then detection simplicity is improved, but false detections increase due to other causes
Solution Approach 1:
The system monitors changes in motor load torque, which is derived from motor speed and inherent torque parameters. By tracking the time derivative of load torque and comparing it against threshold values, the system can distinguish genuine gear shift events from other speed variations, improving detection reliability while maintaining simplicity.
Solution Approach 2:
The control unit continuously calculates motor load torque based on current motor speed and inherent torque values, then compares the rate of change against predetermined threshold values. This feedback mechanism allows the system to reliably identify gear shifts while filtering out false positives from other operating conditions.
3Reliability
If multiple sensor types are used to detect switching operations, then detection reliability is improved, but device complexity and cost increase
Solution Approach 1:
The existing current sensor and speed sensor in the motor controller serve multiple functions: they control motor operation and simultaneously enable gear shift detection through load torque calculation. This multi-functionality eliminates the need for separate detection sensors while maintaining reliable switching detection.
Solution Approach 2:
The motor controller's existing sensing infrastructure is leveraged to perform both motor control and gear shift detection functions. The control unit processes data from existing sensors to calculate motor load torque and detect switching operations, making the system self-sufficient without additional hardware.
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
This method allows for reliable detection of shifting operations without additional sensors, reducing false positives and protecting the drive system by anticipating gear changes, thus enhancing driver comfort and reducing wear on the transmission.
Implementation Method 1
Due to the moment of inertia of the rotating parts of the motor, kinetic energy is absorbed in the rotating system when the speed increases, and kinetic energy is released from the rotating system when the speed of the rotating parts decreases.
Implementation Method 2
kinetic energy is absorbed in the rotating system when the speed increases, and kinetic energy is released from the rotating system when the speed of the rotating parts decreases
Implementation Method 3
the load torque, and thus also the motor current, drops during a switching operation. This is due to an increased back EMF generated by the acceleration of the rotating motor components.
Data Source
Figure 1
Figure 2a~2b
Figure 3a~3b
AI summary
The invention relates to a method for detecting a shift operation (SV) of a transmission of a vehicle (1) which can be driven by the engine force of a motor and/or by pedal force. According to the invention, the engine speed (nMotor) of the engine and the inherent engine torque (Tengineare measured, the engine load torque (Tload) is calculated from the modification of the engine speed (nengine) of the engine and the engine torque (Tengine), and the detection of the shift process is carried out based on the engine torque (Tload). The invention further relates to a shift detection device.