Travel control device, travel control method, and storage medium

Abstract

The present application provides a kind of driving control device, driving control method and storage medium that can reduce the occurrence of jolt when driving.The driving control device of the present application includes target speed calculation unit, keep speed setting unit, control speed setting unit and drive control unit.The driving control device sets specific driving speed as control driving speed and keep driving speed when there is no accelerator operation.In addition, the driving control device sets the detected driving speed as control driving speed and keep driving speed after calculating the target driving speed that exceeds the specific driving speed when setting control driving speed and keep driving speed as specific driving speed.Furthermore, the driving control device sets control driving speed as keep driving speed if the calculated target driving speed is below keep driving speed when control driving speed and keep driving speed are not set as specific driving speed.

Description

Technical Field

[0001] This invention relates to a driving control device, a driving control method, and a storage medium, and particularly to a driving control device, a driving control method, and a storage medium for an automatic transmission vehicle. Background Technology

[0002] Conventional methods for controlling the movement of electric vehicles, such as those described in Patent Document 1, include torque control and speed control. In torque control, control is performed by simply determining a torque command value based on the accelerator's operating amount, and then using this torque command value to operate the motor. Therefore, the calculation of the torque command value does not utilize feedback control, but rather only open-loop control. Thus, in this torque control, the torque command value changes according to changes in the accelerator's operating amount; if the accelerator's operating amount changes within a positive range, the torque command value also changes within a positive range. That is, if the accelerator is used for forward movement, the motor always performs power operation and does not perform regenerative braking.

[0003] On the other hand, in the aforementioned speed control, firstly, the target driving speed is calculated based on the accelerator's operating amount, and then a torque command value is calculated based on the target driving speed. Simultaneously, for example, proportional-integral (PI) control is used to correct the torque command value, thereby eliminating the deviation between the actual driving speed and the calculated target driving speed. Furthermore, in this speed control, the motor is configured such that if the calculated target driving speed is lower than the actual driving speed, a regenerative braking action is performed to reduce the driving speed. Thus, speed control can propel the vehicle at the speed desired by the driver. However, in speed control, the motor exhibits the following behavior: if road surface irregularities cause rapid increases or decreases in accelerator operating amount, the motor can instantly switch between power operation and regenerative braking. In this case, the vehicle will experience a "bumpy" motion, such as leaning forward or backward. Therefore, compared to torque control, speed control offers a less satisfying driving experience in this regard.

[0004] In addition, in speed control, such as Figure 5A As shown, if a driver accelerates the vehicle with the accelerator engaged at 100%, and then reduces the accelerator engagement to 50% at 5 km / h, and continues driving at 5 km / h, if the driver unexpectedly reduces the accelerator excessively at 5 km / h (e.g., reducing the accelerator engagement to 30%), the vehicle may decelerate to a speed slower than 5 km / h. Furthermore, if... Figure 5BAs shown, if a driver releases the accelerator from 100% (0% accelerator operation) to decelerate the vehicle to 5 km / h, and then depresses the accelerator to 50% to maintain the same speed, and continues driving at 5 km / h, if the accelerator is pressed too lightly (e.g., to 30% accelerator operation), the vehicle may decelerate to a speed slower than 5 km / h. As described above, when this unexpected speed occurs, the driver needs to readjust the accelerator operation, and each adjustment may cause a bump. In the case of loading and unloading vehicles such as forklifts, this bumpiness worsens the riding experience compared to regular vehicles and increases the likelihood of goods falling off the forks, thus becoming particularly problematic.

[0005] [Existing Technical Documents]

[0006] [Patent Literature]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2003-267698 Summary of the Invention

[0008] [The problem the invention aims to solve]

[0009] Therefore, the problem to be solved by the present invention is to provide a driving control device, driving control method and storage medium that can reduce the occurrence of bumps during driving.

[0010] [Technical means to solve the problem]

[0011] To address the aforementioned issues, the present invention provides a driving control device for a vehicle, the vehicle comprising an accelerator, a drive unit, and a driving speed detection unit for detecting driving speed.

[0012] The driving control device includes:

[0013] The target speed calculation unit calculates the target travel speed based on the accelerator operation amount;

[0014] The speed setting unit sets and controls the driving speed.

[0015] The speed setting unit sets the driving speed; and

[0016] The drive control unit drives the drive unit to control the vehicle's speed.

[0017] When the accelerator is not in operation, a specific driving speed is set to control and maintain the driving speed.

[0018] When the controlled driving speed and the maintained driving speed are set to a specific driving speed, after calculating the target driving speed that exceeds the specific driving speed, the detected driving speed is set as the controlled driving speed and the maintained driving speed.

[0019] If the controlled driving speed and the maintained driving speed are not set to a specific driving speed, and the calculated target driving speed is below the maintained driving speed, then the controlled driving speed will be kept at the maintained driving speed.

[0020] The driving control device is preferably...

[0021] The specific driving speed is 0 km / h.

[0022] The preferred driving control device is...

[0023] The specific driving speed is below the driving speed during creeping.

[0024] The driving control device is preferably...

[0025] When the controlled driving speed and the maintained driving speed are not set to a specific driving speed, if the calculated target driving speed exceeds the maintained driving speed, the target driving speed is set as the controlled driving speed. As a result, if the driving speed increases and exceeds the maintained driving speed, the maintained driving speed is updated to the controlled driving speed.

[0026] The driving control device is preferably...

[0027] The drive unit is a motor.

[0028] The drive control unit causes the motor to perform a regenerative action during deceleration.

[0029] The driving control device, for example

[0030] The vehicle is an industrial vehicle.

[0031] The driving control device, for example

[0032] The vehicle is a loading and unloading vehicle.

[0033] To address the aforementioned problem, the driving control method of the present invention is a driving control method that enables a vehicle to travel at a controlled driving speed. The vehicle includes an accelerator, a drive unit, and a driving speed detection unit for detecting the driving speed.

[0034] The driving control method, wherein:

[0035] The target speed is calculated based on the accelerator input.

[0036] When the accelerator is not in operation, a specific driving speed is set to control and maintain the driving speed.

[0037] When the controlled driving speed and the maintained driving speed are set to a specific driving speed, after calculating the target driving speed that exceeds the specific driving speed, the detected driving speed is set as the controlled driving speed and the maintained driving speed.

[0038] If the controlled driving speed and the maintained driving speed are not set to a specific driving speed, and the calculated target driving speed is below the maintained driving speed, then the controlled driving speed will be kept at the maintained driving speed.

[0039] The preferred driving control method is,

[0040] When the controlled driving speed and the maintained driving speed are not set to a specific driving speed, if the calculated target driving speed exceeds the maintained driving speed, the target driving speed is set as the controlled driving speed. As a result, if the driving speed increases and exceeds the maintained driving speed, the maintained driving speed is updated to the controlled driving speed.

[0041] To solve the aforementioned problem, the present invention provides a computer-readable storage medium storing a driving control program, wherein:

[0042] The driving control program enables the computer to function as the driving control device.

[0043] [The effects of the invention]

[0044] The driving control device, driving control method, and storage medium of the present invention can reduce the occurrence of bumps during driving. Attached Figure Description

[0045] Figure 1 This is a side view of a forklift according to one embodiment of the present invention.

[0046] Figure 2 This is a functional block diagram illustrating a driving control device according to one embodiment of the present invention.

[0047] Figure 3A and Figure 3B This is a diagram illustrating a driving control method according to one embodiment of the present invention. Figure 3A When indicating acceleration, Figure 3B Indicates deceleration.

[0048] Figure 4 This is a flowchart illustrating a driving control method according to an embodiment of the present invention.

[0049] Figure 5A and Figure 5B This is a diagram illustrating existing driving control methods. Figure 5A When indicating acceleration, Figure 5B Indicates deceleration.

[0050] Explanation of symbols

[0051] 1: Forklift

[0052] 10: Wheels

[0053] 11: Vehicle body

[0054] 12: Mast

[0055] 13: Forklift

[0056] 14: Lifting Unit

[0057] 15: Accelerator

[0058] 16: Storage battery

[0059] 17: Motor (Drive Unit)

[0060] 18: Driving Speed ​​Detection Department

[0061] 2: Driving control device

[0062] 20: Target velocity calculation section

[0063] 21: Maintaining Speed ​​Setting Section

[0064] 22: Speed ​​setting control unit

[0065] 23: Drive Control Unit

[0066] Vo: Control driving speed

[0067] Vn: Driving speed

[0068] Va: Target speed

[0069] Vmax: Maximum driving speed

[0070] Vk: Maintain driving speed

[0071] O: Driver Detailed Implementation

[0072] Hereinafter, a driving control device 2, driving control method, and driving control program according to an embodiment of the present invention will be described with reference to the accompanying drawings. The vehicle in this embodiment is a battery-powered forklift 1, but the vehicle of the present invention is not limited to battery-powered vehicles. The vehicle of the present invention can be any type of vehicle with automatic transmission, such as an engine-powered vehicle. Furthermore, the forklift 1 is only one example; the vehicle of the present invention can also be other industrial vehicles or general vehicles.

[0073] <Forklift>

[0074] First, refer to Figure 1 and Figure 2 The structure of the forklift 1 in this embodiment will be described. Figure 1 As shown, the forklift 1 of this embodiment includes front and rear wheels 10, a body 11, a mast 12, forks 13, a lifting unit 14, an accelerator 15, a battery 16, and a motor 17 (see reference). Figure 2 Motor 17 corresponds to the "drive unit" of this invention. Furthermore, when this invention is applied to an engine-driven vehicle, the engine corresponds to the "drive unit" of this invention.

[0075] The vehicle body 11 is positioned across the front and rear wheels 10, and the mast 12 extends vertically and is located at the front of the vehicle body 11. The forks 13 are configured to rise and fall along the mast 12 via a lifting mechanism 14. The lifting mechanism 14 includes a hydraulic cylinder. The driver O accelerates or decelerates the forklift 1's travel speed Vn by operating an accelerator 15 under their foot. Furthermore, in this invention, "accelerator" is a concept encompassing an accelerator pedal and an accelerator lever.

[0076] The battery 16 is positioned approximately at the center of the vehicle body 11. The front wheels 10 are drive wheels, and drive shafts (not shown) connect the left and right front wheels 10 and the motor 17. The motor 17 is driven by electricity from the battery 16, and its driving torque drives the front wheels 10 via the drive shafts. The motor 17 switches between power operation and regenerative braking based on the input torque command value.

[0077] like Figure 2 As shown, the forklift 1 also includes a computer (not shown) and a travel speed detection unit 18. The computer is located inside the vehicle body 11.

[0078] The computer includes a storage unit, an arithmetic unit, and a memory (not shown). The storage unit stores a driving control program. This driving control program enables the computer to function as a driving control device 2.

[0079] The travel speed detection unit 18 is configured to detect the travel speed Vn of the forklift 1. For example, the travel speed detection unit 18 can also detect the travel speed Vn by detecting the rotational speed of the drive shaft, or by detecting the rotational speed of the motor 17. The travel speed detection unit 18 is not particularly limited in its method of detecting the travel speed Vn. The detected travel speed Vn is output to the travel control device 2.

[0080] <Travel Control Device>

[0081] Next, refer to Figure 2The structure of the driving control device 2 will be described below. The driving control device 2 includes a target speed calculation unit 20, a speed holding unit 21, a speed control unit 22, and a drive control unit 23.

[0082] The target speed calculation unit 20 calculates the target speed Va based on the accelerator input of the driver O. For example, the target speed calculation unit 20 can calculate the target speed using the following formula.

[0083] Formula: Va = Vmax × A

[0084] Va: Target driving speed [km / h]

[0085] Vmax: Maximum driving speed [km / h]

[0086] A: Accelerator operation rate [%)

[0087] In this embodiment, for simplicity, the maximum speed of the forklift 1 is set to 10 km / h. The target speed calculation unit 20 is assumed to be completely proportional to the accelerator operation amount, and calculates the target travel speed Va. Therefore, for example, when the accelerator operation amount is 100%, the target speed calculation unit 20 calculates the target travel speed Va as 10 km / h, and when the accelerator operation amount is 50%, the target travel speed Va is calculated as 5 km / h. The target travel speed Va calculated by the target speed calculation unit 20 is output to the speed setting unit 21 and the speed control unit 22.

[0088] The speed setting unit 21 sets the maintaining travel speed Vk. The forklift 1 is configured to maintain its travel speed Vn at a speed of Vk. The maintaining travel speed Vk set by the speed setting unit 21 is output to the control speed setting unit 22.

[0089] The speed setting unit 22 sets the control driving speed Vo. The set control driving speed Vo is then output to the drive control unit 23.

[0090] The drive control unit 23 drives the motor 17 to travel at the input control travel speed Vo. Specifically, the drive control unit 23 calculates a torque command value to eliminate the deviation between the control travel speed Vo and the travel speed Vn, and outputs the calculated torque command value to the motor 17. The motor 17 is configured to drive according to the input torque command value, thereby causing the forklift 1 to travel at the control travel speed Vo. The torque command value calculated by the drive control unit 23 can be positive or negative, and the motor 17 is configured such that if a positive torque command value is input, a power operation is performed; if a negative torque command value is input, a regenerative operation is performed.

[0091] <Driving Control Methods>

[0092] Next, refer to Figure 3A and Figure 3B as well as Figure 4 The driving control method of driving control device 2 will be explained in detail. Figure 3A and Figure 3B A diagram illustrating the driving control method of this embodiment. Figure 3A This indicates that the speed maintained after acceleration is maintained. Figure 3B This indicates that the speed was maintained after deceleration. For example... Figure 3A As shown, the driving control device 2 is configured such that if the accelerator 15 is decelerated during acceleration, the driving speed Vn at the time of deceleration is maintained. Furthermore, the driving control device 2 is as follows: Figure 3B As shown, it is configured as follows: if the foot leaves the accelerator 15 and the accelerator operation amount becomes 0%, then deceleration occurs; if the accelerator 15 is pressed during deceleration, then the driving speed Vn when the accelerator 15 is pressed is maintained.

[0093] The following is for reference Figure 3A and Figure 3B as well as Figure 4 The operation of the driving control device 2 will be explained in further detail. For example... Figure 4 As shown, Figure 4 The characters in the text represent the following items.

[0094] Vo: Control driving speed [km / h]

[0095] Vn: Detected driving speed [km / h]

[0096] Va: Target driving speed [km / h]

[0097] Vmax: Maximum driving speed [km / h]

[0098] Vk: Maintain driving speed [km / h]

[0099] A: Accelerator operation rate [%)

[0100] F: Accelerator ON / OFF indicator

[0101] First, refer to Figure 3A and Figure 4 The acceleration control and constant speed control of the driving control device 2, which accelerates from 0 km / h (stopped state) to 5 km / h, are explained.

[0102] (1) First, starting from a stopped state, the driver O depresses the accelerator 15, and the target speed calculation unit 20 calculates the target driving speed Va based on the accelerator operation amount (S41). Figure 3A As shown, the accelerator operation is 100%, therefore the target driving speed Va is calculated to be 10 km / h.

[0103] (2) Next, if the accelerator operation is not 0% (No in S42), the accelerator on / off flag is set to off when the vehicle stops (No in S43). Therefore, the accelerator on / off flag is set to on, the detected driving speed Vn (0 km / h here) is set to the maintained driving speed Vk, and the maintained driving speed Vk is set to the control driving speed Vo (S44). That is, if the accelerator 15 is pressed when the vehicle is at 0 km / h, the accelerator on / off flag is first set to on. At this time, the control driving speed Vo is set to 0 km / h, so the forklift 1 has not yet accelerated.

[0104] (3) Next, the target speed Va is calculated again by the target speed calculation unit 20 based on the accelerator operation amount (S41). Similarly, the target speed Va is calculated to be 10 km / h.

[0105] (4) Next, if the accelerator operation is not 0% (No in S42), the accelerator on / off flag is set to on (Yes in S43), and the target travel speed Va exceeds the maintained travel speed Vk (Yes in S45), the accelerator on / off flag is kept on, and the calculated target travel speed Va (10 km / h in this example) is set as the control travel speed Vo (S46). Thus, the drive control unit 23 controls the motor 17 to accelerate the forklift 1 so that the travel speed Vn becomes 10 km / h.

[0106] (5) Furthermore, if the detected driving speed Vn exceeds the maintained driving speed Vk (yes in S47), then the driving speed Vn is set to the maintained driving speed Vk (S48). Thus, the maintained driving speed Vk is updated to the driving speed Vn during acceleration and increases. If the detected driving speed Vn is below the maintained driving speed Vk (no in S47), the maintained driving speed Vk is not changed.

[0107] (6) Next, when the driving speed Vn reaches 5 km / h, the driver O reduces the accelerator operation from 100% to 0 < 50%, and the target speed calculation unit 20 calculates the target driving speed Va based on the accelerator operation (S41). Furthermore, the maintained driving speed Vk at this time... Figure 4 The speed limit on S48 is set at 5 km / h. For example... Figure 3A As shown, the accelerator operation is 0 < 50%, so the target driving speed Va is calculated with a speed of 0 < 5 km / h.

[0108] (7) Next, if the accelerator operation is not 0% (No in S42), the accelerator on / off mark is set to on (Yes in S43). If the target driving speed Va does not exceed the maintained driving speed Vk (No in S45), the accelerator on / off mark is set (maintained) to on, and the control driving speed Vo is set (maintained) to the maintained driving speed Vk (S49). Therefore, since the maintained driving speed Vk is 5 km / h, the control driving speed Vo is set (maintained) to 5 km / h.

[0109] Therefore, by keeping the accelerator input at 0 < 50%, driver O can maintain the forklift 1's travel speed Vn at 5 km / h. As a result, unlike before, when driver O wants to maintain a specific travel speed Vn, a small amount of accelerator input is sufficient, making driving easier. Furthermore, driver O can maintain a constant speed by reducing the accelerator input when Vn reaches the desired speed, thus easily maintaining the desired travel speed.

[0110] Next, refer to Figure 3B and Figure 4 The deceleration control of the driving control device 2, which decelerates from 10 km / h to 5 km / h, is explained.

[0111] (1) First, at a point when the driving speed Vn is 10 km / h, the driver O removes his foot from the accelerator 15 (i.e., accelerator operation is 0%), and the target speed calculation unit 20 calculates the target driving speed Va based on the accelerator operation (S41). Figure 3B As shown, the accelerator operation is 0%, therefore the target driving speed Va is calculated to be 0 km / h.

[0112] (2) Next, since the accelerator operation amount is 0% (S42 is), the accelerator on / off mark is set to off, and the driving speed Vk and the driving speed Vo are set to 0 km / h (S50). As a result, the drive control unit 23 controls the motor 17 to reduce the driving speed Vn by making the driving speed Vn 0 km / h. Figure 4 In S50, "0" corresponds to the "specific driving speed" of the present invention. In this embodiment, the "specific driving speed" of the present invention is set to a speed of 0 km / h, but this is only one example. The "specific driving speed" of the present invention can also be set to a speed other than 0 km / h, as in the variations described below.

[0113] (3) Next, when the driving speed Vn reaches 5 km / h, the driver O depresses the accelerator 15 to reduce the accelerator operation amount to less than 50%, and the target driving speed Va is calculated by the target speed calculation unit 20 based on the accelerator operation amount (S41).

[0114] (4) Thus, the accelerator operation amount is not 0% (No in S42), and the accelerator on / off mark is not set to on (No in S43). Therefore, the accelerator on / off mark is set to on, the detected driving speed Vn (i.e., the speed of 5 km / h) is set to the maintained driving speed Vk, and the maintained driving speed Vk is set to the control driving speed Vo (S44). That is, if the accelerator 15 is decelerated, the driving speed Vn at the time of deceleration (when the accelerator is turned on) is set to the control driving speed Vo. Then, the driver O follows the same procedure as above. In this example, if the accelerator operation amount is kept at 0 < 50%, the driving speed Vn of the forklift 1 can be kept at 5 km / h.

[0115] Therefore, when driver O wants to reduce the driving speed Vn and sets the desired driving speed, he can take his foot off the accelerator 15 to slow down, and when he reaches the desired driving speed, he can press the accelerator 15 to drive at the desired speed.

[0116] As described above, according to the driving control device 2, the driver O no longer needs to repeatedly fine-tune the accelerator operation around the desired speed in order to drive at the desired speed, as was done in the past. Therefore, according to the driving control device 2 of the present invention, the forklift 1 can reduce the occurrence of bumps during driving compared to the past. Furthermore, in the case of conventional vehicle speed control, a speed limit is set separately, and a speed control button is provided, etc., and the vehicle travels at the speed limit by pressing the button, etc. However, according to the driving control device 2, neither setting a speed limit nor providing a speed control button is necessary. The driving control device 2 can set the speed limit to any driving speed simply by operating the accelerator 15, and make the vehicle travel at a constant speed.

[0117] In addition, according to the driving control device 2, even if there are uneven road surfaces that cause the accelerator operation to increase or decrease during constant speed driving, the driving speed Vn will not increase or decrease due to the so-called dead zone of the accelerator 15 during constant speed driving, and can be kept stable.

[0118] The driving control device 2, driving control method, and driving control program according to one embodiment of the present invention have been described above, but the present invention is not limited to the described embodiment. For example, the driving control device, driving control method, and driving control program of the present invention can also be implemented through the following modifications.

[0119] <Variation Example>

[0120] This invention can be applied to vehicles exhibiting or suspected of exhibiting creeping behavior. In such cases, the "specific driving speed" of this invention can be set to 0 km / h, or it can be set to a speed below the speed at which creeping occurs. Furthermore, creeping behavior as described here refers to the phenomenon where the vehicle moves with the engine idling while the accelerator operation is at 0%. Vehicles suspected of exhibiting creeping behavior are those that, although not exhibiting creeping behavior, are set to move at low speeds while the accelerator operation is at 0%.

Claims

1. A driving control device for a vehicle, the vehicle including an accelerator, a drive unit, and a driving speed detection unit for detecting driving speed, characterized in that it includes: The target speed calculation unit calculates the target travel speed based on the accelerator operation amount; The speed setting unit sets and controls the driving speed. The speed setting unit sets the driving speed; and The drive control unit drives the drive unit to make the vehicle travel at the controlled driving speed. During driving, when the accelerator operation reaches 0%, the driving speed is reduced. When the accelerator starts operating, the maintained driving speed is set to the driving speed detected at the start of the accelerator operation, and the controlled driving speed is set to the maintained driving speed. During the operation of the accelerator, if the calculated target driving speed exceeds the maintained driving speed, the controlled driving speed is set to the target driving speed. Consequently, if the driving speed increases and exceeds the maintained driving speed, the maintained driving speed is updated to the target driving speed. During the operation of the accelerator, if the calculated target driving speed is below the maintained driving speed, the controlled driving speed is maintained at the maintained driving speed.

2. The driving control device according to claim 1, characterized in that: The drive unit is a motor. The drive control unit causes the motor to perform a regenerative operation during deceleration.

3. The driving control device according to claim 1, characterized in that: The vehicle in question is an industrial vehicle.

4. The driving control device according to claim 1, characterized in that: The vehicle in question is a loading and unloading vehicle.

5. A driving control method for causing a vehicle to travel at a controlled speed, the vehicle including an accelerator, a drive unit, and a speed detection device for detecting the driving speed, characterized in that: The target speed is calculated based on the accelerator input. During driving, when the accelerator operation reaches 0%, the driving speed is reduced. When the accelerator starts operating, the driving speed is set to the driving speed detected at the start of the accelerator operation, and the controlled driving speed is set to the maintained driving speed. During the operation of the accelerator, if the calculated target driving speed exceeds the maintained driving speed, the controlled driving speed is set to the target driving speed. Consequently, if the driving speed increases and exceeds the maintained driving speed, the maintained driving speed is updated to the target driving speed. During the operation of the accelerator, if the calculated target driving speed is below the maintained driving speed, the controlled driving speed is maintained at the maintained driving speed.

6. A computer-readable storage medium storing a driving control program, characterized in that: The driving control program enables the computer to function as the driving control device as described in claim 1.

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