CVT Torque Control via Power Boundary Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wheeled vehicles with continuously variable transmissions (CVTs) face overheating issues due to excessive torque and power, leading to potential damage, especially during high-load conditions or when operating beyond the designed power capacity.
Innovation Solution
A method involving a control unit that determines the CVT ratio and current power output of the motor, adjusts the torque setting based on pre-determined power boundaries, and controls the engine to operate within safe conditions by reducing torque output when excessive power is applied, using a throttle valve to manage air supply and limit engine torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the motor operates at high power output beyond the designed capacity, then the vehicle can overcome heavy loads and difficult terrain, but the CVT generates excessive heat leading to potential damage
Solution Approach 1:
The control unit continuously monitors the CVT ratio and motor power output, comparing the current power against pre-determined power boundaries specific to each CVT ratio. When the motor power exceeds the safe boundary, the system automatically reduces torque output to prevent CVT overheating, creating a closed-loop feedback control mechanism that dynamically adjusts power delivery based on real-time operating conditions
Solution Approach 2:
The system changes the operating parameters of the motor by adjusting torque output based on the determined torque setting. When power exceeds the power boundary, the control unit modifies the torque parameter to a reduced value that corresponds to safe CVT operating conditions, thereby preventing overheating while maintaining operational capability
2Force
If the CVT operates at high torque settings for extended periods, then the vehicle maintains high pulling capability, but the belt and pulleys overheat and may become damaged
Solution Approach 1:
The system performs preliminary action by pre-determining power boundaries for each CVT ratio before operation. The control unit has already calculated and stored the maximum safe power levels for different transmission ratios, allowing it to proactively prevent overheating by detecting when current power approaches these pre-established limits and reducing torque before dangerous temperature levels are reached
Solution Approach 2:
The control unit acts as an intermediary between the motor and the CVT system. It mediates the power transmission by monitoring the interaction between motor output and CVT ratio, and when necessary, intervenes to reduce torque output to protect the CVT belt and pulleys from excessive heat generation during high-torque operation
3Productivity
If the motor delivers excessive power to the CVT, then the vehicle can achieve higher performance, but the CVT components may be damaged due to sustained high stress and heat
Solution Approach 1:
The control unit implements continuous feedback monitoring of motor power output and CVT ratio, comparing real-time performance against pre-determined power boundaries. When power exceeds safe levels, the system automatically provides feedback-driven torque reduction to maintain CVT durability, creating a self-regulating mechanism that balances performance with component protection
Solution Approach 2:
The system dynamically adjusts the torque setting based on real-time operating conditions. Rather than using a fixed torque limit, the control unit continuously determines appropriate torque settings based on the current CVT ratio and power boundary, allowing the vehicle to optimize performance within safe operational limits while adapting to changing driving conditions
Data Source
AI summary
A method for controlling a motor of a vehicle and the vehicle are presented. The vehicle includes the motor, a control unit, a continuously variable transmission (CVT) comprising a primary pulley, a secondary pulley, and a belt looped around the primary and secondary pulleys, the belt transmitting torque between the primary and secondary pulleys and at least one ground engaging member operatively connected to the secondary pulley. The method is performed at least in part by the control unit. The method comprises determining a CVT ratio of the CVT; determining a current power output of the motor; determining a power boundary based in part on the CVT ratio; determining, when the current power output of the motor is greater than the power boundary, a torque setting based at least in part on the CVT ratio; and controlling the motor to operate under conditions corresponding to the torque setting.