JP7708019B2 - Control device - Google Patents

Description

This disclosure relates to a control device that controls a vehicle that can be remotely driven.

Patent Document 1 discloses an information processing device for suppressing malfunctions that occur when the equipment state of the remote driving device and the equipment state of the remotely driven vehicle do not match when remote driving of the remotely driven vehicle is started by the remote driving device. The information processing device acquires first equipment state information that indicates the equipment state of the remotely driven vehicle that is the subject of remote driving. Then, the remote driving device is controlled based on second equipment state information that indicates the equipment state of the remote driving device and the first equipment state information.

JP 2019-174993 A

When a remote operator remotely drives a remote vehicle that has a transmission, the gears of the remote vehicle may be changed in response to changes in vehicle speed. When a gear change occurs, the acceleration changes even if the accelerator input amount is kept constant, making it difficult for the remote operator to control the vehicle speed, and there is a risk that the vehicle behavior of the remote vehicle may become unstable.

The present disclosure aims to improve the stability of vehicle behavior in a remote vehicle that has a transmission.

The present disclosure relates to a control device that controls a vehicle that is remotely driven by a remote operator and has a transmission that changes gears by changing gear positions.
The control device suppresses the execution of gear shifts while the vehicle is being remotely driven, more so than when the vehicle is not being remotely driven.

The technology disclosed herein can reduce the difficulty that shifting makes in controlling a remote vehicle with a transmission, thereby improving the stability of vehicle behavior.

4 is a time chart for explaining the relationship between gear speed, vehicle speed, and acceleration. 4 is an example of an engagement table to be followed by a transmission mounted on a vehicle according to the present embodiment. 4 is an example of a shift line map used by the control device according to the present embodiment.

An embodiment of the present disclosure will be described with reference to the attached drawings.

1. Overview A remote driving system for a remote operator to remotely drive a vehicle is known. Remote vehicles that are targets of remote driving include remotely driven vehicles and autonomous vehicles. For autonomous vehicles, for example, when it is determined that autonomous driving is difficult, the vehicle may be targeted for remote driving by a remote operator. The remote driving system includes a remote terminal on the remote operator's side and a vehicle terminal on the remote vehicle that is the target of remote driving. Information is transmitted and received between the remote terminal and the vehicle terminal via a communication network. Information acquired from on-board sensors such as a camera, radar, and GPS is transmitted from the vehicle terminal to the remote terminal. The remote operator inputs operation information by operating input devices such as an accelerator and brake provided on the remote terminal based on the information received by the remote terminal. Operation information such as the accelerator, brake, and steering angle input by the remote operator is transmitted from the remote terminal to the vehicle terminal, and the remote vehicle is remotely driven.

Among such remote vehicles, there are vehicles with a transmission that changes gears by changing the gears. When a gear change occurs, the acceleration changes with respect to the accelerator input amount by the remote operator. Figure 1 shows the gear, vehicle speed, and acceleration transitions of a remote vehicle with a transmission in a time chart. The remote operator, who starts remote driving at time T1, operates the input device so that the accelerator input amount is constant. If the gear is not changed, the acceleration with respect to the accelerator input amount does not change, so the vehicle speed increases at a constant acceleration from T1 to T2. At T2, the vehicle speed increases to V2, and the transmission changes gears, changing the gear from the first gear to the second gear. As a result, the acceleration changes due to the gear change from T2 to T3, and the acceleration is no longer constant. In addition, the acceleration with respect to the accelerator input amount changes due to the difference in driving force before and after the gear change, so the acceleration is smaller from T3 onwards than between T1 and T2.

Unlike when a driver is in the vehicle and operating it, in a remote vehicle, the remote operator cannot feel the change in acceleration caused by gear changes. Therefore, if the gear of the remote vehicle is changed while remote driving is being performed, it becomes difficult for the remote operator to control the vehicle speed as desired, and the vehicle's behavior may become unstable. In addition, in a remote driving system, communication delays are likely to occur because information is sent and received between the remote terminal and the vehicle terminal via a communication network. When communication delays occur, a time delay occurs in the vehicle's behavior in response to the remote operator's operation, making it even more difficult for the remote operator to grasp the appropriate amount of operation.

The control device of the present disclosure is a device that controls a remote vehicle having a transmission in order to prevent such situations and increase the stability of the vehicle behavior. The control device may be a device included in a remote terminal, or a device included in a vehicle terminal. The control device suppresses the implementation of gear shifts while remote driving is being performed by a remote operator, compared to when remote driving is not being performed, making gear shifts less likely to occur. An embodiment of the control device is described below.

2. First embodiment In the first embodiment, the control device stops shifting while the remote vehicle is being remotely driven. The transmission forms each gear stage by engaging the clutch and brake according to, for example, the engagement table illustrated in FIG. 2. When the control device is not controlling, for example, the transmission forms a first gear stage by engaging the clutch C1 and the brake B2, and when the vehicle speed increases and reaches a vehicle speed at which upshifting is performed, the transmission performs an upshift from the first gear stage to the second gear stage by releasing the brake B2 and engaging the brake B1 and the clutch C1. Alternatively, for example, the transmission forms a fourth gear stage by engaging the clutch C2 and the brake B1, and when the vehicle speed decreases and reaches a vehicle speed at which downshifting is performed, the transmission performs a downshift from the fourth gear stage to the third gear stage by releasing the brake B1 and engaging the clutch C1 and the clutch C2.

In the first embodiment, the control device prohibits both upshifting when the vehicle speed increases and downshifting when the vehicle speed decreases, and fixes the gear to the gear when remote driving is started. For example, if the gear is first gear when remote driving is started, the clutch C1 and the brake B2 are maintained in an engaged state so that a gear change does not occur even if the vehicle speed increases and reaches a vehicle speed at which the vehicle is upshifted to second gear. Alternatively, for example, if the gear is fourth gear when remote driving is started, the clutch C2 and the brake B1 are maintained in an engaged state so that a gear change does not occur even if the vehicle speed decreases and reaches a vehicle speed at which the vehicle is downshifted to third gear.

In the first embodiment, no gear changes are performed during remote driving, preventing changes in driving force caused by gear changes that would make it difficult for the remote operator to control the vehicle speed. This improves the stability of vehicle behavior.

3. Second embodiment In the second embodiment, the control device also suspends gear shifting while remote driving is being performed. However, in the second embodiment, an upper limit vehicle speed is set for each gear stage, and the suspension of gear shifting is canceled when the traveling vehicle speed exceeds the upper limit vehicle speed. From the viewpoint of component durability, there is a vehicle speed that is desirable not to exceed for each gear stage. The upper limit vehicle speed is a vehicle speed that is set in advance in consideration of such a vehicle speed that is desirable not to exceed. When the vehicle speed increases to the upper limit vehicle speed, the suspension of gear shifting by the control device is canceled, and an upshift is performed. In this way, it is possible to prevent component failure caused by traveling at high speed in a low gear.

In the second embodiment, downshifting is also stopped when the vehicle speed decreases. This is because there is little risk of component failure due to driving at low speed in high gear, and therefore there is little need to set a lower limit vehicle speed for each gear from the standpoint of component durability. In addition, since the upper limit vehicle speed is set to a vehicle speed higher than the vehicle speed at which upshifting occurs normally when remote driving is not being performed, upshifting is also less likely to occur during remote driving than normal. Therefore, even in the second embodiment, the frequency of gear changes can be reduced and the stability of vehicle behavior can be increased.

4. Third embodiment In the third embodiment, the control device also controls the vehicle so that gear shifting is less likely to occur while remote driving is being performed. In the third embodiment, the control device changes the shift line map during remote driving and controls the vehicle so that gear shifting occurs according to a shift line map for remote driving that is different from that used in normal driving. The shift line map for remote driving is a shift line map in which the upshift lines are shifted to the high-speed side and the downshift lines are shifted to the low-speed side compared to the shift line map used in normal driving.

In the third embodiment, gear shifting is not completely stopped even during remote driving. However, by changing the gear shift diagram, gear shifting occurs at a higher speed than normal when the vehicle speed increases, and at a lower speed than normal when the vehicle speed decreases, making gear shifting less likely than normal. In this way, it is possible to reduce situations where gear shifting makes it difficult for the remote operator to control the vehicle speed as desired, while preventing low gears from being used at high vehicle speeds, which could lead to component failure, and high gears from being used at low vehicle speeds, which could result in excessively weak driving force.

Figure 3 shows an example of an upshift line among the shift line diagrams that are changed. The dashed line shows the upshift line in normal operation, and the solid line shows the upshift line during remote operation. By moving the upshift line during remote operation to the higher speed side than the upshift line in normal operation, when the vehicle speed increases, gear changes are performed at a higher vehicle speed than normal, thereby reducing the frequency of gear changes. Note that in the shift line diagram shown in Figure 3, the upshift line during remote operation is simply the normal upshift line shifted to the higher speed side, but the upshift line during remote operation and the upshift line in normal operation may be shift lines of different shapes.

Although not shown, the downshift line during remote driving is changed to a shift line that is the normal downshift line shifted to the lower speed side. This allows gear changes to be performed at a lower vehicle speed than normal when the vehicle speed decreases, reducing the frequency of gear changes. The downshift line during remote driving may simply be the normal downshift line shifted to the lower speed side, or may be a shift line with a different shape than the normal downshift line.

In the third embodiment, the frequency of gear changes can also be reduced during remote driving. This reduces the number of situations in which the remote operator has difficulty controlling the vehicle at the desired speed, and increases the stability of the vehicle's running. At the same time, by not completely ceasing gear changes, it is possible to prevent an excessive decrease in driving force caused by running at a low speed in a high gear, and component failure caused by running at a high speed in a low gear.

Claims (1)

A control device that controls a vehicle that is a target of remote driving by a remote operator and has a transmission that changes gears by changing gear positions,
While the remote driving of the vehicle is being performed, a gear shift is performed according to a remote driving gear shift map that is different from a normal gear shift map that is used when the remote driving is not being performed,
The remote driving shift line map is a shift line map in which the up-shift line is shifted to the high-speed side and the down-shift line is shifted to the low-speed side compared to the normal shift line map.
Control device.