Vehicle running gear

Abstract

To provide a vehicle travel device which can prevent increase in an energy amount consumed to travel of an own vehicle when a distance between a preceding vehicle and a subsequent vehicle becomes short during execution of autonomous acceleration / deceleration control.SOLUTION: A vehicle travel device 10 executes autonomous acceleration / deceleration control of starting coasting control when a distance between a vehicle and a preceding vehicle 200 decreases and reaches a lower limit value, starts acceleration control when the distance with the preceding vehicle increases and reaches an upper limit value, and thereby autonomously controlling acceleration / deceleration of the own vehicle 100 so that the distance with the preceding vehicle is settled within a predetermined range. When a subsequent vehicle exists, and a distance between the preceding vehicle and the subsequent vehicle becomes a predetermined distance or less, during execution of the autonomous acceleration / deceleration control, the vehicle travel device stops the autonomous acceleration / deceleration control, and autonomously controls acceleration / deceleration of the own vehicle so that the distance with the preceding vehicle is kept to be a target distance.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a vehicle running device.

Background Art

[0002] There is known a vehicle running device that executes follow-up running control to run the host vehicle so as to follow a preceding vehicle. Also, as follow-up running control, there is known a vehicle running device that executes autonomous acceleration / deceleration control to reduce the amount of energy consumed in running the host vehicle by causing the host vehicle to coast when decelerating the host vehicle (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] During the execution of the above-described autonomous acceleration / deceleration control, when the distance between the preceding vehicle and the following vehicle is short, while preventing the host vehicle from approaching the preceding vehicle or the following vehicle too closely, if the host vehicle is caused to coast or the host vehicle is accelerated, the coasting and acceleration of the host vehicle will be frequently repeated, and as a result, the amount of energy consumed in running the host vehicle will increase.

[0005] An object of the present invention is to provide a vehicle running device capable of preventing an increase in the amount of energy consumed in running the host vehicle when the distance between the preceding vehicle and the following vehicle is short during the execution of autonomous acceleration / deceleration control.

[0006] The vehicle running gear according to the present invention includes a control device that performs autonomous acceleration and deceleration control, which autonomously controls the acceleration and deceleration of the vehicle so that the distance between the vehicle and the preceding vehicle remains within the predetermined preceding vehicle distance range. This control device starts coasting control to allow the vehicle to coast when the distance between the vehicle and the preceding vehicle decreases and reaches the lower limit of a predetermined preceding vehicle distance range, and starts acceleration control to accelerate the vehicle when the distance between the vehicle and the preceding vehicle increases and reaches the upper limit of the predetermined preceding vehicle distance range. Furthermore, the control device is configured to stop the autonomous acceleration and deceleration control and execute control to autonomously control the acceleration and deceleration of the vehicle so that the distance between the vehicle and the preceding vehicle remains within the predetermined preceding vehicle distance range if a following vehicle is present and the distance between the preceding vehicle and the following vehicle falls below a predetermined distance while the autonomous acceleration and deceleration control is being executed.

[0007] During autonomous acceleration and deceleration control, if there is a following vehicle, it is undesirable for the vehicle to get too close to the following vehicle. On the other hand, when there is a following vehicle and the distance between the preceding vehicle and the following vehicle is short, if the vehicle is allowed to coast or accelerate based on the distance between the vehicle and the preceding vehicle while preventing it from getting too close to the following vehicle, coasting and acceleration control will be repeated frequently, which will increase the amount of energy consumed by the vehicle's movement.

[0008] According to the present invention, when the distance between the preceding vehicle and the following vehicle falls below a predetermined distance, instead of autonomous acceleration and deceleration control, a control system is implemented that autonomously controls the acceleration and deceleration of the vehicle so that the distance between the vehicle and the preceding vehicle is maintained at a target distance. Therefore, it is possible to prevent an increase in the amount of energy consumed by the vehicle's movement when the distance between the preceding vehicle and the following vehicle decreases while autonomous acceleration and deceleration control is being performed.

[0009] Furthermore, in the vehicle running device according to the present invention, the control device may be configured to start acceleration control when the distance between the vehicle and the following vehicle decreases and reaches the lower limit of a predetermined following vehicle distance range, if a following vehicle is present during the execution of the autonomous acceleration / deceleration control, and to end acceleration control when the distance between the vehicle and the following vehicle increases and reaches the upper limit of the predetermined following vehicle distance range.

[0010] According to the present invention, the vehicle accelerates when the distance between the vehicle and the following vehicle decreases, thereby ensuring the driving safety of the vehicle.

[0011] The components of the present invention are not limited to the embodiments described below with reference to the drawings. Other objects, features, and incidental advantages of the present invention will be readily apparent from the description of the embodiments. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a diagram showing a vehicle running gear according to an embodiment of the present invention. [Figure 2] Figure 2(A) shows a scenario where there is a preceding vehicle in front of the vehicle and a following vehicle behind the vehicle, while Figure 2(B) shows a scenario where there is no preceding vehicle in front of the vehicle and a following vehicle behind the vehicle. [Figure 3] Figure 3 is a flowchart showing the routine executed by a vehicle running device according to an embodiment of the present invention. [Figure 4] Figure 4 is a flowchart showing the routine executed by a vehicle running device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0013] Hereinafter, a vehicle running device according to an embodiment of the present invention will be described with reference to the drawings. As shown in Figure 1, the vehicle running device 10 according to an embodiment of the present invention is mounted on the vehicle 100. Hereinafter, the vehicle running device 10 will be described using the case where the operator of the vehicle 100 is a person who is riding in the vehicle 100 and driving the vehicle 100 (i.e., the driver of the vehicle 100) as an example.

[0014] However, the operator of the vehicle 100 may be a person who operates the vehicle 100 remotely without riding in the vehicle 100 (i.e., a remote operator of the vehicle 100). If the operator of the vehicle 100 is a remote operator, the vehicle running gear 10 is installed on the vehicle 100 and on the remote control equipment installed outside the vehicle 100 for remote operation of the vehicle 100, and the functions of the vehicle running gear 10 described below are shared between the vehicle running gear 10 installed on the vehicle 100 and the vehicle running gear 10 installed on the remote control equipment.

[0015] The vehicle running gear 10 is equipped with an ECU (Electronic Control Unit) 90. The ECU 90 mainly consists of a microcomputer. The microcomputer includes a CPU, ROM, RAM, non-volatile memory, and interfaces. The CPU is configured to perform various functions by executing instructions, programs, or routines stored in the ROM. In this example, the vehicle running gear 10 is equipped with one ECU, but as will be described later, it may be equipped with multiple ECUs and configured to have each of the ECUs perform the various processes described later.

[0016] The vehicle running gear 10 performs autonomous acceleration and deceleration control as an automatic driving control. Autonomous acceleration and deceleration control is a control that drives the vehicle 100 by autonomously controlling the drive unit 20 and the braking unit 30 to accelerate and decelerate the vehicle 100, and in this example, it is inter-vehicle distance control and driving speed control. In this example, the drive unit 20 is equipped with an internal combustion engine 21 and a motor 22, and the braking unit 30 is equipped with a hydraulic brake unit 31.

[0017] Inter-vehicle distance control is a control function that is executed when a preceding vehicle 200 is present in front of the vehicle 100, as shown in Figure 2(A). It is an autonomous acceleration / deceleration control that autonomously accelerates and decelerates the vehicle 100 based on the target preceding vehicle distance DFtgt.

[0018] The preceding vehicle 200 is another vehicle traveling ahead of the vehicle 100 and within a predetermined distance (preceding vehicle detection distance DFth) from the vehicle 100. The vehicle running device 10 detects the preceding vehicle 200 based on the surrounding detection information IS, which will be described later.

[0019] Furthermore, the target distance between vehicles DFtgt is the distance between vehicles DF set by the driver as the control target by the distance control system. The distance between vehicles DF is the distance between the vehicle 100 and the vehicle 200 ahead. The vehicle running gear 10 acquires the distance between vehicles DF based on the surrounding detection information IS, which will be described later.

[0020] On the other hand, as shown in Figure 2(B), the driving speed control is a control that is executed when there is no preceding vehicle 200 in the direction of the vehicle 100, and is an autonomous acceleration and deceleration control that autonomously accelerates and decelerates the vehicle 100 based on the set speed Vset. The set speed Vset is the driving speed of the vehicle 100 (vehicle speed Vego) set by the driver as the control target by the driving speed control. The vehicle running device 10 acquires the vehicle speed Vego by the vehicle speed detection device 40.

[0021] Next, the operation of the vehicle running gear 10 will be explained in more detail. The vehicle running gear 10 executes the routine shown in Figure 3 at a predetermined calculation cycle. When the vehicle running gear 10 starts processing from step S300 of the routine shown in Figure 3, it proceeds to step S305 and determines whether the autonomous acceleration / deceleration control execution condition C0 is met. The autonomous acceleration / deceleration control execution condition C0 is the condition that the execution of autonomous acceleration / deceleration control is requested. The driver can request the execution of autonomous acceleration / deceleration control from the vehicle running gear 10 by operating the autonomous acceleration / deceleration control request operator 51 (driving support button).

[0022] When the vehicle traveling device 10 determines "Yes" in step S305, the process proceeds to step S310 to determine whether the first condition C1 is satisfied. The first condition C1 is a condition that the execution of the second autonomous acceleration / deceleration control (economy driving control) is not required. The driver can request the vehicle traveling device 10 to execute the second autonomous acceleration / deceleration control by operating the second autonomous acceleration / deceleration control request operator 52 (economy driving button). Also, in this example, the second autonomous acceleration / deceleration control is the second inter-vehicle distance control and the second traveling speed control, which will be described later.

[0023] When the vehicle traveling device 10 determines "Yes" in step S310, the process proceeds to step S315 to determine whether a preceding vehicle 200 exists. The vehicle traveling device 10 determines whether a preceding vehicle 200 exists based on the surrounding detection information IS.

[0024] The surrounding detection information IS is information provided from the surrounding information detection device 60. In this example, the surrounding information detection device 60 includes a radar sensor 61 and a camera sensor 62. The surrounding information detection device 60 provides the vehicle traveling device 10 with the information (radar detection information) of the surroundings of the host vehicle 100 acquired by the radar sensor 61 as the surrounding detection information IS. Also, the surrounding information detection device 60 provides the vehicle traveling device 10 with the image data (image information) of the surroundings of the host vehicle 100 acquired by the camera sensor 62 as the surrounding detection information IS.

[0025] When the vehicle traveling device 10 determines "Yes" in step S315, the process proceeds to step S320 to execute the first inter-vehicle distance control, and then the process proceeds to step S395 to temporarily end the processing of this routine.

[0026] The first inter-vehicle distance control is a control that maintains the distance DF between vehicles ahead at a target distance DFtgt, and in this example, it is one of the first autonomous acceleration / deceleration controls. More specifically, the first inter-vehicle distance control is a control that autonomously controls the drive unit 20 and the braking unit 30 to accelerate or decelerate the vehicle 100 so that the distance DF between vehicles ahead is maintained at a target distance DFtgt. Therefore, the first inter-vehicle distance control is a so-called follow-me driving control or adaptive cruise control.

[0027] On the other hand, if the vehicle running gear 10 determines "No" in step S315, it proceeds to step S325 to execute the first running speed control, and then proceeds to step S395 to terminate the processing of this routine.

[0028] The first driving speed control is a control that maintains the vehicle speed Vego at a set speed Vset, and in this example, it is one of the first autonomous acceleration / deceleration controls. More specifically, the first driving speed control is an autonomous acceleration / deceleration control that accelerates or decelerates the vehicle 100 by autonomously controlling the drive unit 20 and the braking unit 30 so that the vehicle speed Vego is maintained at the set speed Vset. Therefore, the first driving speed control is a so-called constant speed driving control or cruise control.

[0029] Furthermore, if the vehicle running gear 10 determines "No" in step S310, it proceeds to step S330 to determine whether or not a preceding vehicle 200 exists. That is, if the first condition C1 is not met in step S310, and therefore the second condition C2, which states that the execution of the second autonomous acceleration / deceleration control (economy driving control) is required, is met, the vehicle running gear 10 proceeds to step S330 to determine whether or not a preceding vehicle 200 exists.

[0030] If the vehicle running device 10 determines "Yes" in step S330, it proceeds to step S335 and executes the routine shown in Figure 4, as described later, to perform the second inter-vehicle distance control, and then proceeds to step S395 to terminate the processing of this routine.

[0031] The second inter-vehicle distance control is generally an autonomous acceleration / deceleration control that autonomously controls the acceleration and deceleration of the vehicle 100 so that the distance between the vehicle 100 and the preceding vehicle 200 (preceding inter-vehicle distance DF) remains within the predetermined preceding inter-vehicle distance range Rd. This is achieved by starting coasting control to allow the vehicle 100 to coast when the distance between the vehicle 100 and the preceding vehicle 200 (preceding inter-vehicle distance DF) increases and reaches the upper limit of a predetermined distance range (predetermined preceding inter-vehicle distance range Rd), and starting acceleration control (optimal acceleration control) to accelerate the vehicle 100 when the distance between the vehicle 100 and the preceding vehicle 200 (preceding inter-vehicle distance DF) decreases and reaches the lower limit of the predetermined preceding inter-vehicle distance range Rd (forward lower limit distance DFlower).

[0032] In other words, the second inter-vehicle distance control is generally a control that maintains the preceding inter-vehicle distance DF within a predetermined preceding inter-vehicle distance range Rd, which includes a target preceding inter-vehicle distance DFtgt. When the preceding inter-vehicle distance DF increases and reaches the upper limit of the predetermined preceding inter-vehicle distance range Rd (forward upper limit distance DFupper), optimal acceleration control is executed. When the preceding inter-vehicle distance DF decreases and reaches the lower limit of the predetermined preceding inter-vehicle distance range Rd (forward lower limit distance DFlower), coasting control is executed.

[0033] Furthermore, the second inter-vehicle distance control may be configured to control the start and end of optimal acceleration control based on the distance DF between the preceding vehicle, as described above, as well as the distance between the following vehicle 300 and the own vehicle 100 (distance DR between following vehicles).

[0034] In this case, the vehicle running gear 10 is configured to start optimal acceleration control when the following vehicle distance DR decreases and reaches the lower limit of a predetermined distance range (predetermined following vehicle distance range) (rear lower limit distance DRlower), and then permit the termination of optimal acceleration control when the following vehicle distance DR increases and reaches the upper limit of the predetermined following vehicle distance range (rear upper limit distance DRupper). In this case, the vehicle running gear 10 may also be configured to start coasting control when it permits the termination of optimal acceleration control, or it may be configured to continue optimal acceleration control when it permits the termination of optimal acceleration control and the preceding vehicle distance DF is smaller than the forward lower limit distance DFlower. In this case, if the preceding vehicle distance DF reaches the forward lower limit distance DFlower before it permits the termination of optimal acceleration control, the vehicle running gear 10 terminates optimal acceleration control and starts coasting control.

[0035] Furthermore, the following vehicle 300 is another vehicle traveling behind the own vehicle 100 and within a predetermined distance (following vehicle detection distance DRth) from the own vehicle 100. The vehicle driving device 10 detects the following vehicle 300 based on the surrounding detection information IS.

[0036] On the other hand, if the vehicle running device 10 determines "No" in step S330, it proceeds to step S340 to execute the second running speed control, and then proceeds to step S395 to temporarily terminate the processing of this routine.

[0037] The second speed control is a control that maintains the vehicle speed Vego within a predetermined speed range Rv, including the set speed Vset. When the vehicle speed Vego decreases and reaches the lower limit of the predetermined speed range Rv (lower speed Vlower), the drive unit 20 is controlled to accelerate the vehicle 100. When the vehicle speed Vego increases and reaches the upper limit of the predetermined speed range Rv (upper speed Vupper), the drive unit 20 is controlled to decelerate the vehicle 100.

[0038] In particular, the second speed control is a control system that accelerates the vehicle 100 by executing optimal acceleration control when the vehicle speed Vego decreases and reaches the lower limit speed Vlower, and decelerates the vehicle 100 by executing coasting control when the vehicle speed Vego increases and reaches the upper limit speed Vupper.

[0039] Optimal acceleration control is a control that controls the drive unit 20 so that power is output from the drive unit 20 with the highest energy efficiency, and in particular, a control that operates the internal combustion engine 21 at the optimal operating point (or an operating point near the optimal operating point).

[0040] On the other hand, coasting control is a control that controls the drive unit 20 so that the vehicle 100 travels by coasting.

[0041] Furthermore, if the vehicle running device 10 determines "No" in step S305, it proceeds directly to step S395 and terminates the processing of this routine.

[0042] Next, the routine shown in Figure 4 will be explained. When the vehicle running device 10 proceeds to step S335 of the routine shown in Figure 3, it starts processing from step S400 of the routine shown in Figure 4, proceeds to step S405, and determines whether or not a following vehicle 300 exists.

[0043] If the vehicle running gear 10 determines "Yes" in step S405, it proceeds to step S410 to determine whether the distance between the front and rear vehicles DX is less than or equal to a predetermined distance (predetermined distance between front and rear vehicles DXth).

[0044] The front-to-rear distance DX is the distance between the preceding vehicle 200 and the following vehicle 300, and is obtained based on surrounding detection information IS. Furthermore, the predetermined front-to-rear distance DXth should be set appropriately so as to ensure the driving safety of the vehicle 100. For example, if the second inter-vehicle distance control is configured to start optimal acceleration control when the following vehicle distance DR decreases and reaches the rear lower limit distance DRlower, and to start coasting control when the following vehicle distance DR increases and reaches the rear upper limit distance DRupper which is greater than the rear lower limit distance DRlower, then the predetermined front-to-rear distance DXth is set to a value greater than the sum of the rear upper limit distance DRupper and the front lower limit distance DFlower.

[0045] If the vehicle running device 10 determines "Yes" in step S410, it proceeds to step S415 to perform the first inter-vehicle distance control, and then proceeds to step S495 to terminate the processing of this routine.

[0046] On the other hand, if the vehicle running gear 10 determines "No" in step S410, it proceeds to step S420. Also, if the vehicle running gear 10 determines "No" in step S405, it proceeds to step S420.

[0047] When the vehicle running gear 10 proceeds to step S420, it determines whether the distance DF between vehicles is greater than or equal to the forward upper limit distance DFupper. If the vehicle running gear 10 determines "Yes" in step S420, it proceeds to step S425 to execute optimal acceleration control, and then proceeds to step S495 to terminate the processing of this routine.

[0048] On the other hand, if the vehicle running gear 10 determines "No" in step S420, it proceeds to step S430 to determine whether the distance DF between vehicles is less than or equal to the lower limit distance DFlower. If the vehicle running gear 10 determines "Yes" in step S430, it proceeds to step S435 to perform coasting control, and then proceeds to step S495 to temporarily terminate the processing of this routine.

[0049] On the other hand, if the vehicle running gear 10 determines "No" in step S430, it proceeds directly to step S495 and terminates the processing of this routine.

[0050] The above describes the operation of the vehicle running gear 10.

[0051] <Effects> During the execution of the second-stage distance control, if there is a following vehicle 300, it is undesirable for the vehicle 100 to get too close to the following vehicle 300. On the other hand, when there is a following vehicle 300 and the distance between the front and rear vehicles DX is short, if the vehicle 100 is allowed to coast or accelerate based on the distance between the preceding vehicle DF while preventing the vehicle 100 from getting too close to the following vehicle 300, coasting control and optimal acceleration control will be repeated frequently, which will result in a large amount of energy being consumed by the vehicle 100 during its movement.

[0052] According to the vehicle running gear 10, when the distance DX between the front and rear vehicles falls below a predetermined distance DXth, the first distance control is executed instead of the second distance control. Therefore, it is possible to prevent an increase in the amount of energy consumed by the vehicle 100 when the distance DX between the front and rear vehicles is shortened while the second distance control is being executed.

[0053] Furthermore, the present invention is not limited to the embodiments described above, and various modifications can be adopted within the scope of the present invention. [Explanation of Symbols]

[0054] 10...Vehicle running gear, 20...Drive system, 30...Braking system, 60...Surrounding information detection system, 61...Radar sensor, 62...Camera sensor, 90...ECU, 100...Own vehicle, 200...Preceding vehicle, 300...Following vehicle

Claims

1. A vehicle running gear includes a control device that performs autonomous acceleration and deceleration control, which autonomously controls the acceleration and deceleration of the vehicle so that the distance between the vehicle and the preceding vehicle remains within the predetermined preceding vehicle distance range, by starting coasting control to allow the vehicle to coast when the distance between the vehicle and the preceding vehicle decreases and reaches the lower limit of a predetermined preceding vehicle distance range, and starting acceleration control to accelerate the vehicle when the distance between the vehicle and the preceding vehicle increases and reaches the upper limit of the predetermined preceding vehicle distance range. The control device is configured to stop the autonomous acceleration / deceleration control when, during the execution of the autonomous acceleration / deceleration control, a following vehicle is present and the distance between the preceding vehicle and the following vehicle falls below a predetermined distance, and to autonomously control the acceleration / deceleration of the vehicle so that the distance between the vehicle and the preceding vehicle is maintained at a target distance. Vehicle running gear.

2. In the vehicle running device according to claim 1, The control device is configured such that, during the execution of the autonomous acceleration and deceleration control, if a following vehicle is present, it starts the acceleration control when the distance between the vehicle and the following vehicle decreases and reaches the lower limit of a predetermined following vehicle distance range, and then terminates the acceleration control when the distance between the vehicle and the following vehicle increases and reaches the upper limit of the predetermined following vehicle distance range. Vehicle running gear.

Images