Hybrid Drive Speed Synchronization Control
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Solution Overview
Problem
Hybrid vehicle drive systems experience deceleration issues when restarting due to differences in rotating speeds of rotary elements connected through coupling elements, leading to an unpleasant ride for the operator.
Innovation Solution
A control apparatus is implemented to manage the output torques of electric motors, ensuring the speed difference between rotary elements of the first and second differential mechanisms is reduced to a predetermined threshold before the coupling element is engaged during system restart, thereby minimizing deceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the coupling element is engaged to connect the rotary elements of the first and second differential mechanisms, then the drive system can be restarted and vehicle drive modes can be switched, but a difference in rotating speeds between the two rotary elements causes deceleration felt by the operator
Solution Approach 1:
The control apparatus performs preliminary speed synchronization by controlling the output torque of at least one electric motor before the coupling element is engaged. This reduces the rotating speed difference between the two rotary elements to a predetermined threshold or less, preventing the deceleration sensation during system restart while maintaining the ability to switch between drive modes
2Object-affected harmful factors
If the rotating speed difference between rotary elements is reduced before coupling element engagement, then operator comfort is improved, but control complexity increases
Solution Approach 1:
The control apparatus continuously monitors the rotating speeds of the two rotary elements and adjusts the output torque of the electric motor(s) based on the detected speed difference. This feedback control mechanism automatically maintains speed synchronization within the predetermined threshold, improving operator comfort without requiring complex manual intervention
Solution Approach 2:
The control apparatus utilizes the existing electric motors in the hybrid drive system to perform the speed synchronization function. By controlling the output torque of motors that are already part of the system, the invention achieves speed matching without adding separate synchronization mechanisms, thereby limiting the increase in overall system complexity
Data Source
AI summary
A hybrid drive apparatus and a control apparatus for controlling the hybrid drive apparatus, a hybrid drive apparatus including a differential device made of a first differential mechanism and second differential mechanism, including four rotary components; and an engine, a first electric motor, second electric motor and an output rotary member, which are respectively connected to four rotary components, wherein one of the four rotary components consists of a rotary element of the first differential mechanism and a rotary element of the second differential mechanism which are selectively connected to each other through a coupling element, and the control apparatus controlling at least one of output torques of the first and second electric motors, to reduce a difference between rotating speeds of the rotary elements of the first and second differential mechanisms selectively connected to each other through the coupling element, to a value not larger than a predetermined threshold value, before the coupling element is brought into an engaged state when the drive system is re-started after the drive system is once placed in an off state.