Parking Lock Release Control Using Main Motor Torque Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle control devices face challenges in appropriately releasing the parking lock mechanism, particularly when meshing surface pressure is generated due to vehicle inclination or other factors, leading to insufficient torque output from the actuator to perform the release.
Innovation Solution
The vehicle control device includes an actuator drive control section, a main motor drive control section, and a stagnation determination section, which reduces the main motor torque based on detected sensor values to manage meshing surface pressure and ensure proper release of the parking lock, utilizing the main motor to compensate for the actuator's torque limitations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the actuator is used to drive the parking lever, then the parking lock can be released, but the actuator torque is insufficient when meshing surface pressure is generated
Solution Approach 1:
The patent combines the main motor and actuator into a unified drive system where the main motor provides primary torque for overcoming meshing surface pressure, while the actuator assists in precise positioning and final engagement. This merging allows the system to leverage both the high torque capability of the main motor and the precision control of the actuator, resolving the torque insufficiency issue while maintaining reliable parking lock release.
Solution Approach 2:
The control unit acts as an intermediary that coordinates between the main motor and actuator. It manages the torque distribution and timing, allowing the main motor to compensate for actuator torque limitations during high-resistance phases of parking lever movement, ensuring reliable release even when meshing surface pressure is generated.
2Reliability
If the main motor torque is increased to overcome meshing surface pressure, then the parking lock can be released, but heat generation in the main motor increases
Solution Approach 1:
The control unit implements periodic or pulsed torque application from the main motor rather than continuous high torque. By applying torque in controlled intervals and adjusting the duty cycle, the system can overcome meshing surface pressure when needed while allowing cooling periods that reduce overall heat generation in the main motor.
Solution Approach 2:
The control unit dynamically adjusts main motor torque parameters based on real-time conditions such as meshing surface pressure detection. By changing torque magnitude, duration, and application timing, the system achieves reliable parking lock release while optimizing heat generation through adaptive parameter control rather than fixed high torque settings.
3Volume of moving object
If the actuator is miniaturized, then the device size is reduced, but the torque output capability is further limited
Solution Approach 1:
The control unit serves as an intermediary that compensates for the reduced actuator torque through intelligent coordination with the main motor. It manages the torque distribution, timing, and sequencing, allowing the miniaturized actuator to operate within its reduced capability while the main motor provides the necessary torque augmentation to achieve the required parking lever movement.
Solution Approach 2:
The system merges the functions of torque generation and precision control between the main motor and miniaturized actuator. The main motor handles the high-torque requirements for overcoming meshing pressure, while the compact actuator handles precise positioning, creating a synergistic system that achieves both size reduction and sufficient torque output.
4Reliability
If the parking lever is driven with high torque, then the parking lock can be released from engaged state, but shock occurs when the parking lever collides with the parking gear
Solution Approach 1:
The control unit implements preliminary action by gradually increasing main motor torque before full engagement and preparing the system for the collision event. It pre-positioning the parking lever and controlling the approach speed, then manages the torque application to minimize impact shock while ensuring the parking lock is reliably released from the engaged state.
Solution Approach 2:
The control unit provides beforehand cushioning by controlling the torque application profile to reduce the impact of collision between the parking lever and parking gear. It manages the deceleration and torque reduction timing to cushion the impact, preventing harmful shock while maintaining reliable release functionality.
Data Source
AI summary
A vehicle control device includes an actuator drive control section that controls drive of an actuator, a main motor drive control section that controls drive of a main motor, and a stagnation determination section. The stagnation determination section determines a stagnation of the actuator based on a detected value of a sensor unit that detects a physical quantity that changes according to a drive state of the actuator. When performing a meshing surface pressure reduction control for reducing a meshing surface pressure generated at the meshing point between a parking gear and a parking lever by driving the main motor, the main motor drive control section decreases a main motor torque which is a torque of the main motor based on the detected value of the sensor unit.