Automatic parking control device

1. An automatic parking control device applied to a vehicle that is equipped with a drive device and a brake device and is configured to execute an automatic parking control that automatically moves the vehicle to a target parking position, the drive device including an internal combustion engine and a torque converter and being configured to output a vehicle driving force transmitted to a wheel of the vehicle, the brake device being configured to generate a vehicle braking force applied to the wheel,

the automatic parking control including a driving force change cancellation control that controls the brake device so as to generate the vehicle braking force that cancels a change in the vehicle driving force associated with a change in actual idle speed of the internal combustion engine when a target idle speed changes in response to an idle speed change request,

the automatic parking control device comprising an electronic control unit configured, in the driving force change cancellation control, to:

execute a rotation prediction process to calculate a predicted idle speed change portion corresponding to a change portion of an idle speed obtained by advancing a change portion of the actual idle speed associated with a change in the target idle speed by a brake response delay time from a time point at which a target vehicle braking force is instructed to the brake device to a time point at which a change in the vehicle braking force starts;

execute a driving force prediction process to calculate a predicted driving force change portion corresponding to a change portion of the vehicle driving force according to the predicted idle speed change portion;

execute a braking force control process to calculate, as a change portion of the target vehicle braking force, a change portion of the vehicle braking force that cancels the predicted driving force change portion and instruct a calculated vehicle braking force change portion to the brake device; and

when the brake response delay time is longer than an engine response delay time being a response delay time of the actual idle speed with respect to the change in the target idle speed, execute a rotational speed control delay process to delay the change in the target idle speed, by a rotational speed control delay time, from a time point at which the idle speed change request is issued, the rotational speed control delay time being longer than or equal to a difference obtained by subtracting the engine response delay time from the brake response delay time.

2. The automatic parking control device according to claim 1 , wherein

the rotation prediction process includes at least one of a predicted rotational speed delay process, a rate limiting process, and a first-order delay process to calculate a waveform of the predicted idle speed change portion based on a waveform of the target idle speed,

the predicted rotational speed delay process delays a change start time point of the waveform of the predicted idle speed change portion so as to be delayed from a change start time point of the waveform of the target idle speed by a predicted rotational speed delay time corresponding to a difference obtained by subtracting the brake response delay time from the engine response delay time,

the rate limiting process delays a slope of the waveform of the predicted idle speed change portion so as to be equal to or smaller than a maximum slope of the change in the actual idle speed that can be generated by the internal combustion engine, and

the first-order delay process is applied to a waveform of the target idle speed without any of the predicted rotational speed delay process and the rate limiting process, or a waveform of the predicted idle speed change portion after at least one of the predicted rotational speed delay process and the rate limiting process.

3. The automatic parking control device according to claim 2 , wherein

the rotation prediction process includes all of the predicted rotational speed delay process, the rate limiting process, and the first-order delay process.

4. The automatic parking control device according to claim 2 , wherein

the rotation prediction process includes an interpolation process to calculate a final predicted idle speed change portion by interpolation for each time step based on the predicted idle speed change portion after at least one of the predicted rotational speed delay process, the rate limiting process, and the first-order delay process, and the change portion of the actual idle speed associated with the change in the target idle speed.

5. The automatic parking control device according to claim 2 , wherein

the predicted rotational speed delay time is longer when cooling water temperature of the internal combustion engine is lower.

6. The automatic parking control device according to claim 2 , wherein

the slope of the waveform of the predicted idle speed change portion after being limited by the rate limiting process is smaller when cooling water temperature of the internal combustion engine is lower.

7. An automatic parking control device applied to a vehicle that is equipped with a drive device and a brake device and is configured to execute an automatic parking control that automatically moves the vehicle to a target parking position, the drive device including an internal combustion engine and a torque converter and being configured to output a vehicle driving force transmitted to a wheel of the vehicle, the brake device being configured to generate a vehicle braking force applied to the wheel,

the automatic parking control including a driving force change cancellation control that controls the brake device so as to generate the vehicle braking force that cancels a change in the vehicle driving force associated with a change in actual idle speed of the internal combustion engine when a target idle speed changes in response to an idle speed change request,

the automatic parking control device comprising an electronic control unit configured, in the driving force change cancellation control, to:

execute a rotation prediction process to calculate a predicted idle speed change portion corresponding to a change portion of an idle speed obtained by advancing a change portion of the actual idle speed associated with a change in the target idle speed by a brake response delay time from a time point at which a target vehicle braking force is instructed to the brake device to a time point at which a change in the vehicle braking force starts;

execute a driving force prediction process to calculate a predicted driving force change portion corresponding to a change portion of the vehicle driving force according to the predicted idle speed change portion; and

execute a braking force control process to calculate, as a change portion of the target vehicle braking force, a change portion of the vehicle braking force that cancels the predicted driving force change portion and instruct a calculated vehicle braking force change portion to the brake device, wherein

the rotation prediction process includes at least one of a predicted rotational speed delay process, a rate limiting process, and a first-order delay process to calculate a waveform of the predicted idle speed change portion based on a waveform of the target idle speed,

the predicted rotational speed delay process delays a change start time point of the waveform of the predicted idle speed change portion so as to be delayed from a change start time point of the waveform of the target idle speed by a predicted rotational speed delay time corresponding to a difference obtained by subtracting the brake response delay time from an engine response delay time being a response delay time of the actual idle speed with respect to the change in the target idle speed,

the rate limiting process delays a slope of the waveform of the predicted idle speed change portion so as to be equal to or smaller than a maximum slope of the change in the actual idle speed that can be generated by the internal combustion engine, and

the first-order delay process is applied to a waveform of the target idle speed without any of the predicted rotational speed delay process and the rate limiting process, or a waveform of the predicted idle speed change portion after at least one of the predicted rotational speed delay process and the rate limiting process.

8. The automatic parking control device according to claim 7 , wherein

the rotation prediction process includes all of the predicted rotational speed delay process, the rate limiting process, and the first-order delay process.

9. The automatic parking control device according to claim 7 , wherein

the rotation prediction process includes an interpolation process to calculate a final predicted idle speed change portion by interpolation for each time step based on the predicted idle speed change portion after at least one of the predicted rotational speed delay process, the rate limiting process, and the first-order delay process, and the change portion of the actual idle speed associated with the change in the target idle speed.

10. The automatic parking control device according to claim 7 , wherein

the predicted rotational speed delay time is longer when cooling water temperature of the internal combustion engine is lower.

11. The automatic parking control device according to claim 7 , wherein

the slope of the waveform of the predicted idle speed change portion after being limited by the rate limiting process is smaller when cooling water temperature of the internal combustion engine is lower.