Vehicle Drive-Force Control Apparatus State Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control apparatuses for vehicle drive-force transmitting apparatuses struggle to accurately determine the operation state of the second engagement device, leading to potential slippage in belt-type continuously-variable transmission mechanisms due to reliance on hydraulic pressure command values alone, without considering actual operational states or device failures.
Innovation Solution
A control apparatus that determines the operation state of the second engagement device by evaluating transition-completion conditions based on both the state of hydraulic control and rotational speed differences, allowing for precise identification of states such as fully released, fully engaged, releasing process, and engaging process states, and calculates input torque for the continuously-variable transmission mechanism accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the operation state of the second engagement device is determined only based on hydraulic pressure command values, then the control system is simple, but the determination accuracy is insufficient leading to potential slippage
Solution Approach 1:
The patent implements feedback by detecting the actual rotational speeds of the input and output rotary members and comparing the measured rotational speed difference against predetermined thresholds. This feedback mechanism enables accurate determination of the engagement device's operation state (fully released, releasing process, fully engaged, or disengaging process) based on real operational data rather than relying solely on hydraulic pressure command values, thereby preventing slippage while maintaining control system simplicity
Solution Approach 2:
The patent replaces the traditional mechanical/hydraulic state detection method with an electronic detection system that measures rotational speed difference. Instead of using complex hydraulic pressure sensors or mechanical position indicators, the system uses rotational speed sensors to detect the operational state of the engagement device, substituting a simpler electronic measurement approach that provides more accurate and reliable state determination
2Reliability
If the gear ratio control prioritizes prevention of excessive rotation of the secondary pulley, then the transmission mechanism is protected, but the gear ratio control accuracy deteriorates when engagement device state is misidentified
Solution Approach 1:
The patent applies preliminary action by establishing predetermined rotational speed difference thresholds that define the boundaries between different operation states of the engagement device. These thresholds are set in advance to clearly distinguish between fully released, releasing process, fully engaged, and disengaging process states. By having these thresholds pre-defined, the control system can accurately identify the current operation state and apply appropriate gear ratio control strategies, ensuring both transmission protection and control accuracy without conflict
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 approach enables accurate determination of the operation state of the second engagement device, preventing slippage and ensuring proper gear ratio control, thereby improving the reliability and efficiency of the drive-force transmission.
Implementation Method 1
a second engagement device whose operation state is to be switched among a plurality of states including a fully released state, a fully engaged state, a releasing process state and an engaging process state, by a hydraulic pressure which is supplied to the second engagement device and which is subjected to a hydraulic control
Implementation Method 2
a continuously-variable transmission mechanism including primary and secondary pulleys and a transfer element that is looped over the primary and secondary pulleys
Data Source
AI summary
A control apparatus for a vehicle drive-force transmitting apparatus that defines first and second drive-force transmitting paths between input and output rotary members. The second drive-force transmitting path is established by engagement of a second engagement device. The control apparatus includes an operation-state determining portion configured to determine which one of a plurality of states is established as an operation state of the second engagement device, by determining whether a plurality of transition-completion conditions, each of which is required to determine that a transition of the operation state of the second engagement device to a corresponding one of the plurality of states from another of the plurality of states has been completed, are satisfied or not, based on (α) a state of a hydraulic control executed to control a hydraulic pressure supplied to the second engagement device and (β) a rotational speed difference of the second engagement device.