CVT Control Apparatus for Rapid Acceleration Response
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Solution Overview
Problem
Existing control techniques for vehicles with continuously variable transmissions fail to provide quick acceleration as expected by the operator after a rapid release of the accelerator pedal, leading to a difference in actual and expected acceleration and a risk of delay in vehicle acceleration.
Innovation Solution
A control apparatus that determines the operator's acceleration requirement, sets a restricted accelerator operation amount that increases with vehicle speed, and controls the speed ratio of the continuously variable transmission using a second restricted operation amount setting portion to decrease the accelerator operation amount at a lower rate than the actual decrease, and an upper limit stop processing portion to limit the operation amount, ensuring rapid acceleration without exceeding the actual operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the output torque of the vehicle drive power source and the speed ratio of the continuously variable transmission are controlled to follow the highest fuel economy line, then fuel economy is improved, but acceleration performance deteriorates
Solution Approach 1:
The control apparatus dynamically adjusts the target vehicle drive force based on the operating state of the vehicle drive power source. When the power source operates in a high-speed region beyond the highest fuel economy line, the system increases the target vehicle drive force to improve acceleration response, while maintaining fuel economy control in other operating regions
Solution Approach 2:
The system changes the control parameter (target vehicle drive force) based on the operating conditions. By monitoring the operating state of the vehicle drive power source and adjusting the target vehicle drive force accordingly, the system achieves both fuel economy and acceleration performance
2Speed
If the target vehicle drive force is temporarily increased to improve acceleration performance, then acceleration performance is improved, but initial acceleration shock is generated
Solution Approach 1:
The control apparatus detects rapid releasing actions of the vehicle accelerating member in advance and preemptively adjusts the target vehicle drive force to prevent excessive acceleration. By identifying the rapid release pattern and responding with controlled force adjustment, the system prevents both insufficient acceleration and harmful acceleration shocks
3Object-affected harmful factors
If the rates of increase and decrease of the actual amount of operation of the vehicle accelerating member are smoothed, then initial acceleration and deceleration shocks are mitigated, but acceleration response delay is generated
Solution Approach 1:
The control system dynamically adjusts the target vehicle drive force based on the detected operating state of the vehicle accelerating member. When rapid releasing action is detected, the system responds with appropriate force adjustment rather than applying fixed smoothing, thereby maintaining acceleration responsiveness while preventing harmful shocks
Data Source
AI summary
A control apparatus for a vehicle with a continuously variable transmission, having an acceleration requirement determining portion determining operator required acceleration, a first restricted accelerator operation amount setting portion setting an accelerating member restricted operation amount that increases with a running speed increase, when the determining portion has determined required vehicle acceleration, and a shift control portion controlling the transmission speed ratio on the restricted amount basis, the control apparatus having: a second restricted accelerator operation amount setting portion decreasing the restricted amount from a value immediately prior to an accelerating member rapid releasing action determination moment, at a rate lower than an accelerating member operation actual amount decrease rate after the rapid releasing action determination moment, and an upper limit stop processing portion to limit the restricted amount after a determination moment that the operator requires vehicle acceleration, the restricted amount is not larger than the actual operation amount.