Automated Driving Torque Control Without Downshift Shock
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Solution Overview
Problem
Existing in-vehicle control devices perform downshifting during automated driving even when the increase in requested driving force is due to slight gradients or curving, leading to gearshift shock and noise for drivers and passengers, thereby reducing drivability.
Innovation Solution
The in-vehicle control device prioritizes driving force increase from the electric motor over traditional engine-based downshifting, allowing for increased driving force without downshifting the transmission, thus suppressing gearshift shock and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If downshifting is performed to increase driving force during automated driving, then driving force is improved, but gearshift shock and noise increase, reducing drivability
Solution Approach 1:
The patent replaces the traditional mechanical downshifting approach with an electric motor-based driving force increase approach. When driving force increase is requested during automated driving, the system prioritizes increasing output from the electric motor rather than performing transmission downshifting, thereby eliminating gearshift shock and noise while maintaining improved driving force.
2Power
If downshifting is performed in response to predicted driving force increase, then driving force is improved, but unexpected gearshift shock occurs on slight gradients or curves, reducing drivability
Solution Approach 1:
The system substitutes electric motor control for mechanical downshifting control. The processor determines whether driving force increase is truly necessary by analyzing multiple parameters including vehicle speed, acceleration, gradient, and curve information. When increase is needed, it commands the electric motor to increase output rather than downshifting, eliminating unexpected gearshift events on slight gradients or curves.
Solution Approach 2:
The system uses feedback from multiple sensors (vehicle speed sensor, acceleration sensor, gradient sensor, curve information) to continuously monitor driving conditions and adjust electric motor output accordingly. This feedback mechanism allows the system to respond appropriately to actual driving needs without unnecessary downshifting events.
Data Source
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AI summary
An in-vehicle control device (40) is configured to be installed in a vehicle (20) including an engine (22), a transmission (30) configured to change speed of motive power of the engine (22) and perform output to a drive shaft (36) connected to a drive wheel, an electric motor (26) configured to input and output motive power to and from the drive shaft (36), a power storage device (29) configured to input and output electric power to and from the electric motor (26), and a steering device (34). The in-vehicle control device (40) includes a processor (41), and the processor (41) is configured to, at a time of driving force increase request when a driving force increase request is made to bring the vehicle (20) into a predetermined target state during the automated driving control, give priority to driving force increase from the electric motor (26) without downshifting the transmission (30), over driving force increase that involves downshifting the transmission (30).