Vehicle air conditioning control method and vehicle air conditioning device
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
When restoring the compressor capacity from a minimized state during fuel cutting in vehicles, there is a variation in the torque profile of load torque, leading to unstable engine torque control and potential discomfort for vehicle occupants due to fluctuating deceleration rates.
Innovation Solution
The discharge capacity of the air-conditioning compressor is set to a minimum capacity during fuel cutting, then temporarily increased to an upper limit capacity, and after a predetermined time, adjusted to match the cabin state, stabilizing the torque profile and deceleration rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the compressor capacity is minimized during fuel cutting, then fuel economy is improved and engine load is reduced, but when the capacity is restored to normal operation, torque profile variation occurs causing unstable engine torque control and occupant discomfort
Solution Approach 1:
The control method applies preliminary action by pre-adjusting the compressor capacity in a staged manner before full restoration is needed. When transitioning from fuel cutting to normal operation, the compressor capacity is first increased to an intermediate level, then after a predetermined time elapsed, further adjusted to the target capacity. This preliminary staged adjustment prevents sudden torque profile variations that would cause engine torque control instability and occupant discomfort.
2Speed
If the compressor capacity is restored quickly to normal operation, then air conditioning responsiveness is improved, but torque profile variation causes unstable deceleration rate and occupant discomfort
Solution Approach 1:
The control method segments the compressor capacity restoration process into distinct stages: first transitioning from minimum capacity to an intermediate capacity level, then after a predetermined time elapsed, transitioning to the target capacity. This segmentation of the restoration process prevents sudden large changes in compressor load, thereby avoiding torque profile variations that would cause unstable deceleration rates and occupant discomfort, while still achieving relatively quick overall restoration.
Data Source
AI summary
During control of an air-conditioning for a vehicle, when a torque to the engine is outputted that satisfies a total value of drive torques of the vehicle and an air-conditioning compressor, a minimum discharge capacity is set when fuel to the engine is cut. An assessment is made as to whether or not the discharge capacity needs to be changed from the minimum discharge capacity in accordance with the state inside the cabin. The discharge capacity is changed from the minimum discharge capacity to an upper limit capacity that is allowed during normal operation upon accessing that the discharge capacity needs to be changed from the minimum discharge capacity. After a predetermined time elapses following the changing of the discharge capacity, the discharge capacity is changed from the upper limit capacity to a discharge capacity that corresponds to the state inside the cabin.