Travel control device, travel control method, travel control program, and vehicle manufacturing method

Abstract

To improve production efficiency of a vehicle that uses a motor as a drive source.SOLUTION: A travel control device (10) comprises: a wheel speed acquisition unit (30) configured to acquire wheel speeds of tires (111, 112, 121, 122) of a base vehicle (100A) that can automatically travel using motors (89, 90) as drive sources in a manufacturing process of a vehicle (100); and a torque control unit (31) configured to calculate a request torque for making the base vehicle travel at a low speed on the basis of the acquired wheel speeds, and perform control such that the motors are driven with the calculated request torque.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a driving control device, a driving control method, a driving control program, and a vehicle manufacturing method. [Background technology]

[0002] Patent Document 1 discloses a manufacturing method for an automobile capable of automatic driving while recognizing and following a vehicle in front, the manufacturing method comprising: a first assembly process in which running parts including tires and wheels, a drive source that drives the wheels, a power supply device that supplies a power source for operating the drive source, a sensor for recognizing the vehicle in front, and a control device that controls the drive source so that the vehicle follows the vehicle in front based on information obtained from the sensor are assembled to a vehicle to be manufactured, thereby making the vehicle to be manufactured capable of automatic driving; a second assembly process in which, after the first assembly process, interior parts are assembled to the vehicle to be manufactured while causing the vehicle to automatically drive so as to follow an adjacent vehicle in front; and, after the second assembly process, an inspection process in which the completed vehicle to be manufactured is inspected. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-100179 A Summary of the Invention [Problem to be solved by the invention]

[0004] When manufacturing vehicles powered by a motor in a factory, production efficiency can be improved by assembling parts while the vehicle is automatically traveling at a low speed.

[0005] An object of the present disclosure is to provide a driving control device, a driving control method, a driving control program, and a vehicle manufacturing method that make it possible to improve the production efficiency of vehicles that are driven by a motor. [Means for solving the problem]

[0006] A driving control device according to a first aspect of the present disclosure includes a wheel speed acquisition unit that acquires, during a vehicle manufacturing process, the wheel speed of tires of a base vehicle capable of automatic driving using a motor as a driving source, and a torque control unit that calculates a required torque for driving the base vehicle at a low speed based on the acquired wheel speed, and controls the motor to be driven with the calculated required torque.

[0007] A driving control method according to a second aspect includes a process in which at least one processor executes a process for acquiring wheel speed of tires of a base vehicle capable of automatic driving using a motor as a driving source during a vehicle manufacturing process, calculating a required torque for driving the base vehicle at a low speed based on the acquired wheel speed, and controlling the motor to be driven with the calculated required torque.

[0008] A driving control program according to a third aspect causes at least one processor to execute processing including acquiring, during a vehicle manufacturing process, a wheel speed of tires of a base vehicle capable of automatic driving using a motor as a driving source, calculating a required torque for driving the base vehicle at a low speed based on the acquired wheel speed, and controlling the motor to be driven with the calculated required torque.

[0009] A vehicle manufacturing method according to a fourth aspect manufactures a vehicle by sequentially assembling parts to a base vehicle equipped with a driving control device according to the first aspect while the base vehicle is being driven autonomously. Effect of the Invention

[0010] According to the present disclosure, it is possible to improve the production efficiency of vehicles that are driven by a motor. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of a vehicle configuration. [Diagram 2] FIG. 1 is a configuration diagram of a vehicle management system. [Diagram 3] FIG. 2 is a block diagram showing a hardware configuration of a driving control device. [Figure 4] FIG. 2 is a diagram illustrating a functional configuration of a driving control device. [Diagram 5] 4 is a flowchart of a driving control process. [Figure 6] 4 is a flowchart of a low-speed driving control process. [Figure 7] 13 is a flowchart of a step estimation process. [Figure 8] FIG. 13 is a diagram showing a state in which a wheel comes into contact with a step. [Figure 9A] 1 is a graph showing a trajectory of a rotational axis of a wheel. [Figure 9B] 13 is a graph showing a trajectory angle. [Figure 10] 13 is a flowchart of a process for determining whether one or both wheels are climbing up. [Figure 11] 4 is a flowchart of a vehicle stop and travel restart determination process. [Figure 12] 4 is a flowchart of vehicle stopping control. [Figure 13] 13 is a graph showing a trajectory angle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and duplicated description will be omitted.

[0013] A schematic configuration of a vehicle 100 according to this embodiment is shown in the block diagram of Fig. 1. A vehicle cruise control device 10 according to this embodiment is mounted on the vehicle 100 and configured as a device for controlling the operation of the vehicle 100.

[0014] The vehicle 100 is equipped with a driving control device 10, four tires 111, 112, 121, 122, wheel speed sensors 81, 82, 83, 84, reduction gears 85, 86, drive shafts 87, 88, motors 89, 90 as drive sources, resolvers 91, 92, a brake oil pressure sensor 93, a longitudinal acceleration sensor 94, a lateral acceleration sensor 95, inverters 96, 97, current sensors 98, 99, a battery 110, and a brake ECU 120.

[0015] The vehicle 100 is structured to run by transmitting power from drive motors 89 and 90 to tires 111, 112, 121 and 122.

[0016] The motors 89 and 90 generate driving force at rotation speeds controlled by inverters 96 and 97, respectively. The driving forces generated by the motors 89 and 90 are then transmitted to four tires 111, 112, 121 and 122 via reduction gears 85 and 86 and drive shafts 87 and 88.

[0017] The reduction gears 85 and 86 reduce the rotation speed generated by the motors 89 and 90, respectively. The reduction gears 85 and 86 also function as differential gears (differential devices) that absorb the difference in rotation speed between the left and right tires when the vehicle 100 goes around a curve, etc.

[0018] The motors 89 and 90 also function as generators that regenerate braking energy generated when braking the vehicle 100 using regenerative braking, convert it into electrical energy, and charge the battery 110 .

[0019] In this manner, the motors 89 and 90 are configured to function as electric motors as well as generators, and are called motor generators (MG).

[0020] In this embodiment, the vehicle 100 is described as a four-wheel drive vehicle that is provided with two motors 89, 90 and drives four wheels, namely, front wheels 111, 112 and rear wheels 121, 122. However, the present invention is not limited to such a case, and the technology disclosed herein can be similarly applied to a case where only the front wheels 111, 112 are driven, or a case where only the rear wheels 121, 122 are driven.

[0021] Also, instead of the two motors 89, 90, a so-called in-wheel motor may be provided for each of the tires 111, 112, 121, and 122. Also, an in-wheel motor may be provided only for the tires 111 and 112, which are the front wheels, or an in-wheel motor may be provided only for the tires 121 and 122, which are the rear wheels.

[0022] In addition, in this embodiment, the present invention is applied to an electric vehicle whose only driving sources are motors 89, 90, but the technology disclosed herein can also be applied to a hybrid vehicle equipped with a gasoline engine and a motor.

[0023] The wheel speed sensors 81, 82, 83, and 84 detect the wheel speeds, which are the rotational speeds of the tires 111, 112, 121, and 122, respectively, and output the detected wheel speeds to the cruise control device 10 as vehicle speed pulses.

[0024] The brake oil pressure sensor 93 detects the brake oil pressure generated when braking the vehicle 100, and outputs brake torque information to the driving control device 10. The brake ECU 120 performs brake control when braking the vehicle 100.

[0025] The longitudinal acceleration sensor 94 detects the longitudinal acceleration G of the vehicle 100. X The lateral acceleration sensor 95 is a G sensor that detects the lateral acceleration G of the vehicle 100 and outputs the detected acceleration G to the cruise control device 10. Y The G sensor detects the acceleration and output the detected acceleration to the cruise control device 10.

[0026] The resolvers 91 and 92 are provided to rotate together with the motors 89 and 90, and detect the motor rotation speed ω M It functions as a rotation speed detection unit that detects the rotation speed.

[0027] Further, current sensors 98, 99 are provided on the inverters 96, 97, respectively. The current sensors 98, 99 detect the motor currents flowing through the motors 89, 90, respectively, and output the detected motor currents to the driving control device 10 as information on the motor current values.

[0028] The driving control device 10 controls the driving of the vehicle 100 based on information input from various sensors and the like as described above, and calculates a required torque T MG The inverters 96 and 97 output the requested torque T MG Based on this, the drive control of the motors 89 and 90 is performed using power supplied from the battery 110.

[0029] In this embodiment, the motor 89, the inverter 96 that drives the motor 89, and the reduction gear 85 that reduces the rotational speed of the motor 89 are mounted on the vehicle 100 as an integrated drive unit 101. Similarly, the motor 90, the inverter 97, and the reduction gear 86 are mounted on the vehicle 100 as an integrated drive unit 102.

[0030] When manufacturing vehicle 100 in a factory, a basic vehicle 100A (see FIG. 2) equipped with the minimum parts required for autonomous driving is driven autonomously while parts are sequentially assembled onto basic vehicle 100A to manufacture the vehicle.

[0031] In this embodiment, the basic vehicle 100A includes at least one of a drive unit 101 and a drive unit 102, a battery 110 that supplies power to the inverters 96, 97, and the cruise control device 10.

[0032] Furthermore, to make the basic vehicle 100A automatically travel at low speeds, signals detected by sensors such as the longitudinal acceleration sensor 94 and the lateral acceleration sensor 95 are required, as described below. For this reason, the basic vehicle 100A may be equipped with the sensors in advance, but there are also cases where the sensors cannot be equipped from the beginning. In such cases, the sensors may be temporarily equipped on the basic vehicle 100A, and the temporarily equipped sensors may be removed after the vehicle 100 is completed.

[0033] FIG. 2 shows a vehicle management system 1 that manages the autonomous driving of a basic vehicle 100A when the vehicle 100 is manufactured in a factory.

[0034] As shown in FIG. 2, the vehicle management system 1 has a configuration in which a vehicle management device 2 and a plurality of cameras 3 installed in a factory are connected via a network 4.

[0035] The multiple cameras 3 are installed at positions where they can capture images of the multiple basic vehicles 100A that are automatically traveling within the factory.

[0036] The vehicle management device 2 analyzes images captured by the multiple cameras 3, grasps the positions of the multiple base vehicles 100A traveling automatically within the factory, and transmits the target vehicle speed and steering angle of each base vehicle 100A to each base vehicle 100A via the network 4 so that each base vehicle 100A can travel automatically along a predetermined course at an appropriate speed and interval. The vehicle management device 2 also instructs each base vehicle 100A to stop and resume traveling as necessary.

[0037] Fig. 3 is a block diagram showing a hardware configuration of the driving control device 10 of the vehicle 100. As shown in Fig. 3, the driving control device 10 includes a control unit 21. The control unit 21 is configured from a device including a general computer.

[0038] 3, the control unit 21 includes a central processing unit (CPU) 21A, a read only memory (ROM) 21B, a random access memory (RAM) 21C, and an input / output interface (I / O) 21D. The CPU 21A, the ROM 21B, the RAM 21C, and the I / O 21D are connected to each other via a bus 21E. The bus 21E includes a control bus, an address bus, and a data bus.

[0039] In addition, a communication unit 22 and a storage unit 23 are connected to the I / O 21D.

[0040] The communication unit 22 is an interface for communicating with the brake ECU 120 and the various sensors described above.

[0041] The storage unit 23 is configured with a non-volatile external storage device such as a hard disk, etc. As shown in Fig. 3, the storage unit 23 stores a driving control program 23A and the like.

[0042] The CPU 21A is an example of a computer. The term "computer" used here refers to a processor in a broad sense, and includes a general-purpose processor (e.g., a CPU) or a dedicated processor (e.g., a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic device, etc.).

[0043] The driving control program 23A may be stored in a non-volatile non-transitory recording medium, or may be distributed via a network and appropriately installed in the driving control device 10, thereby being stored in the storage unit 23. The driving control program 23A may also be appropriately updated by so-called OTA (Over The Air).

[0044] Examples of non-volatile non-transient recording media include CD-ROMs (Compact Disc Read Only Memory), magneto-optical disks, HDDs (Hard Disk Drives), DVD-ROMs (Digital Versatile Disc Read Only Memory), flash memories, memory cards, and the like.

[0045] Fig. 4 is a block diagram showing a functional configuration of the CPU 21A of the cruise control device 10. As shown in Fig. 3, the CPU 21A functionally includes a wheel speed acquisition unit 30, a torque control unit 31, a step estimation unit 32, a determination unit 33, a target vehicle speed acquisition unit 34, a steering angle acquisition unit 35, a steering angle control unit 36, and a weight acquisition unit 37.

[0046] The driving control device 10 has functions other than those shown in FIG. 4, but functions other than those related to this embodiment are omitted in FIG.

[0047] During the manufacturing process of the vehicle 100, the wheel speed acquisition unit 30 acquires the wheel speeds of the tires 111, 112, 121, 122 of the basic vehicle 100A that is capable of automatic travel using motors 89, 90 as drive sources from the wheel speed sensors 81, 82, 83, 84.

[0048] The torque control unit 31 calculates a required torque T for running the base vehicle 100A at a low speed based on the acquired wheel speed. MG Calculate the required torque T MG The motors 89 and 90 are controlled to be driven at a speed of 1 kph (1 km / h) or more and 2 kph (2 km / h) or less in this embodiment.

[0049] The step estimating unit 32 estimates the height of the step with which the tires 111, 112, 121, and 122 are in contact.

[0050] The determination unit 33 determines, based on the amount of change per unit time of the trajectory angle, which is the angle that the trajectory of the rotation center axis of the tires 111, 112, 121, 122 makes with respect to the road surface, and the height of the step, at least one of whether the base vehicle 100A has been pushed to cause the stopped base vehicle to automatically drive, and whether the base vehicle 100A has been pushed to stop the automatically driving base vehicle 100A. In this case, when it is determined that the base vehicle 100A has been pushed to cause the stopped base vehicle 100A to automatically drive, the torque control unit 31 determines the required torque T MG If it is determined that the basic vehicle 100A is pushed in order to stop the basic vehicle 100A during automatic driving, the required torque T MG Calculate.

[0051] In addition, the torque control unit 31 performs control to stop a diagnostic fail-safe function that performs abnormality diagnosis of the vehicle 100 before the basic vehicle 100A is made to run autonomously in the manufacturing process.

[0052] The target vehicle speed acquisition unit 34 acquires a low target vehicle speed from the vehicle management device 2. The torque control unit 31 calculates a required torque T MG Calculate.

[0053] The steering angle acquisition unit 35 acquires the steering angle from the vehicle management device 2. The steering angle control unit 36 ​​controls the steering angle of the basic vehicle 100A based on the acquired steering angle. This allows the basic vehicle 100A to run on a predetermined course in the manufacturing process.

[0054] The weight acquisition unit 37 acquires the weight of the base vehicle 100A transmitted from the vehicle management device 2 every time a part is assembled to the base vehicle 100A. In this case, the torque control unit 31 calculates the required torque T MG Calculate.

[0055] When the vehicle management device 2 instructs the torque control unit 31 to perform low-speed driving control to automatically drive the vehicle 100 at a constant low speed, the torque control unit 31 determines a required torque T for driving the basic vehicle 100A at a low speed based on the wheel speed estimated by the wheel speed acquisition unit 30. MG Calculate the required torque T MG The motors 89 and 90 are driven by feedback control. The feedback control may be so-called PI feedback control, PD feedback control, or PID feedback control.

[0056] By performing such low-speed driving control, it becomes possible to automatically drive the basic vehicle 100A at the manufacturing site and perform assembly.

[0057] On the other hand, when normal driving control is instructed instead of low-speed driving control, the torque control unit 31 generates a driver requested torque to be output to the motors 89, 90 based on the accelerator opening degree of the accelerator operation by the driver, and calculates the generated driver requested torque as requested torque T MG and outputs the signal to inverters 96 and 97.

[0058] The CPU 21A reads and executes a driving control program 23A stored in the storage unit 23, thereby functioning as each of the functional units shown in FIG.

[0059] Next, a driving control process executed by the CPU 21A of the control unit 21 will be described with reference to Fig. 5. The driving control process shown in Fig. 5 is executed when the system of the vehicle 100 is turned on, and is repeatedly executed until the system is turned off. In addition, the following describes a case where the tires 111, 112 are driven by the motor 89, that is, a case where the vehicle is front-wheel driven.

[0060] In step S100, the CPU 21A determines whether the low-speed driving control flag is ON. In this embodiment, when the vehicle 100 is to be automatically driven at a constant low speed without requiring accelerator or brake operation, such as when the basic vehicle 100A is to be automatically driven at a manufacturing site for assembly, the low-speed driving control flag is set to ON by the vehicle management device 2 and notified to the driving control device 10. On the other hand, when normal driving control is to be performed by the driver's accelerator and brake operation rather than low-speed driving control, the low-speed driving control flag is set to OFF by the vehicle management device 2 and notified to the driving control device 10.

[0061] If the low speed running control flag is ON, the process proceeds to step S101, and if the low speed running control flag is OFF, the process proceeds to step S103.

[0062] In step S101, the CPU 21A stops the diagnostic fail-safe function. The diagnostic fail-safe function is a safety function that performs abnormality diagnosis and performs control such as stopping the vehicle 100 when some abnormality occurs. When performing low-speed traveling control, the diagnostic fail-safe function is stopped to prevent erroneous detection of an abnormality.

[0063] In step S102, the CPU 21A executes the low speed traveling control shown in FIG.

[0064] On the other hand, in step S103, the CPU 21A starts a diagnostic fail-safe function. That is, when the normal driving control is executed, the diagnostic fail-safe function is started, and if any abnormality occurs during the normal driving control, a safety function such as stopping the vehicle 100 is activated.

[0065] In step S104, the CPU 21A executes normal driving control, that is, controls the vehicle 100 so that the vehicle 100 drives in response to the accelerator operation and the brake operation of the driver.

[0066] Next, details of the low-speed driving control in step S102 will be described with reference to Fig. 6. In this embodiment, the low-speed driving control in Fig. 6 is executed in the manufacturing process of the vehicle 100 when parts are sequentially assembled while a basic vehicle 100A equipped with the driving control device 10 automatically drives along a predetermined course to manufacture the vehicle 100.

[0067] In step S200, the CPU 21A, as the target vehicle speed acquisition unit 34, determines whether or not the target vehicle speed has been acquired from the vehicle management device 2. If the target vehicle speed has been acquired, the process proceeds to step S201, and if the target vehicle speed has not been acquired, the process waits until the target vehicle speed is acquired.

[0068] In step S201, the CPU 21A calculates the required torque T corresponding to the target vehicle speed acquired in step S200, for example, 1 kph. MG to the inverter 96. As a result, the base vehicle 100A starts traveling at the target vehicle speed, and the worker begins assembling the necessary parts. After the base vehicle 100A starts traveling, if the vehicle management device 2 instructs the base vehicle 100A to stop traveling, the base vehicle 100A stops traveling, and if the vehicle management device 2 instructs the base vehicle 100A to resume traveling, the base vehicle 100A resumes traveling.

[0069] In step S202, the CPU 21A, functioning as the wheel speed acquisition unit 30, acquires the wheel speeds of the tires 111 and 112 from the wheel speed sensors 81 and .

[0070] In step S203, the CPU 21A functions as the step estimation unit 32 and executes the step estimation process shown in FIG.

[0071] In step S204, the CPU 21A, functioning as the determination unit 33, executes the vehicle stop and travel restart determination process shown in FIG.

[0072] In step S205, the CPU 21A, functioning as the torque control unit 31, executes a required torque calculation process shown in FIG.

[0073] After the base vehicle 100A starts traveling, the vehicle management device 2 transmits a steering angle to the base vehicle 100A so that the base vehicle 100A travels along a predetermined traveling course.

[0074] Therefore, in step S206, the CPU 21A, as the steering angle acquisition unit 35, determines whether or not the steering angle has been acquired from the vehicle management device 2. If the steering angle has been acquired from the vehicle management device 2, the process proceeds to step S207, and if the steering angle has not been acquired from the vehicle management device 2, the process proceeds to step S208.

[0075] In step S207, the CPU 21A, functioning as the steering angle control unit 36, controls the steering mechanism of the tires 111, 112 so that the steering angle of the tires 111, 112 becomes the steering angle acquired in step S206.

[0076] When the manufacture of the vehicle 100 is completed, the vehicle management device 2 turns off the low speed driving control flag and notifies the driving control device 10 of this.

[0077] In step S208, CPU 21A determines whether the low speed running control flag has been turned OFF. If the low speed running control flag is ON, that is, if the manufacture of vehicle 100 has not been completed and low speed running control is to be continued, the process returns to step S202 and repeats the processes of steps S202 to S207. On the other hand, if the low speed running control flag has been turned OFF, the process proceeds to step S209.

[0078] In step S209, the CPU 21A stops the traveling of the vehicle 100 whose production has been completed. MG The output of the power to the inverter 96 is stopped, and the vehicle 100 is stopped.

[0079] Next, the step estimation process in step S203 will be described in detail with reference to FIG.

[0080] In step S300, the CPU 21A calculates the maximum value h maxSpecifically, first, the vertical load Fz is calculated. The vertical load Fz is a force applied downward to the tires 111, 112. The vertical load Fz is calculated as the total value of the forces applied to the tires 111, 112 by the following formula.

[0081] JPEG2025066577000002.jpg19128...(1)

[0082] "m" in the first term on the right-hand side of the above equation (1) is the current weight of the base vehicle 100A. The weight m of the base vehicle 100A gradually increases as parts are successively assembled as the manufacturing process progresses. The vehicle management device 2 knows the current weight m of the base vehicle 100A from a predetermined production plan. For this reason, in step S300, the vehicle management device 2 is requested to transmit the current weight m of the base vehicle 100A, and this is acquired. Note that the vehicle management device 2 may transmit the current weight m of the base vehicle 100A to the driving control device 10 every time the weight of the base vehicle 100A changes.

[0083] "g" is the gravitational acceleration. "l" is the length of the wheelbase of the base vehicle 100A. "lr" is the length in the front-rear direction from the center of gravity of the base vehicle 100A to the central axis of rotation of the rear wheels (tires 121, 122). "G X " is the acceleration in the direction of travel of the basic vehicle 100A, i.e., the front-rear direction, and can be obtained from the front-rear acceleration sensor 94. cg " is the height from the road surface to the center of gravity of the base vehicle 100A. The first term on the right side of the above equation (1) represents the downward component of the force applied to each of the tires 111, 112 as the dynamic load when the base vehicle 100A is running.

[0084] The second term on the right side of the above formula (1) is "d S " is the damping coefficient of the damper (not shown) of the basic vehicle 100A. spd " is the running speed along the longitudinal direction of the base vehicle 100A. V spdcan be calculated based on the wheel speed acquired in step S202 of FIG. old " is the value of the trajectory angle θ calculated in the previous control cycle. When the process of FIG. 7 is executed for the first time, θ old For example, 0 is used as the value of . The second term on the right side of the above equation (1) represents the force applied to each of the tires 111 and 112 in association with the expansion and contraction of the damper.

[0085] Next, the trajectory angle θ is calculated. Here, the trajectory angle θ is explained. The "trajectory angle" is the angle that the trajectory of the rotational center axis of the tire 111 etc. forms with the road surface.

[0086] 8 is a schematic diagram showing a state in which the tire 111 is on a road surface RD. A step ST that serves as a wheel stopper is provided on the road surface RD, and a part of the tire 111 is in contact with the step ST. If the basic vehicle 100A attempts to move further to the right (i.e., toward the step ST) from the state shown in FIG. 8, the tire 111 will run up onto the step ST.

[0087] The graph shown by the solid line in Fig. 9A represents the relationship between the travel distance (horizontal axis) of the base vehicle 100A and the height (vertical axis) of the rotation center axis AX of the tire 111 when the base vehicle 100A travels toward the right as described above. It can be said that this graph represents the trajectory of the rotation center axis AX while the base vehicle 100A is traveling. θ shown in Fig. 9A is the angle that the trajectory of the rotation center axis AX of the tire 111, etc. makes with the road surface, and represents the trajectory angle when the vehicle 100 is at the position X1. Such a trajectory angle θ can be defined corresponding to each position of the base vehicle 100A.

[0088] As mentioned above, the "path angle" refers to the angle that the path of the rotation axis AX of the tire 111, etc., makes with respect to the road surface, but the "path of the rotation axis AX" here refers to the path of the rotation axis AX when the vehicle 100 is viewed in its left-right direction (vehicle width direction). The path of the rotation axis AX as shown in the graph of FIG. 9A reflects to some extent the shape of the step ST indicated by the dashed line in the figure. The reason why the two shapes are different from each other is that the tire 111 is not a rigid body and is deformed when it hits the step ST.

[0089] The trajectory angle θ can be calculated by the following formula.

[0090] JPEG2025066577000003.jpg29125...(2)

[0091] On the right side of the above equation (2), "T M " is the motor torque of the motor 89, and "R" is the dynamic radius of the tire 111. M / R" indicates the driving force applied to the road surface by the driving wheels of the basic vehicle 100A. M can detect the motor torque generated in the motor 89 based on the motor current value detected by the current sensor 98.

[0092] Next, a locus angle θ′ when the tire 111 is an ideal disk is calculated from the locus angle θ by the following formula.

[0093] JPEG2025066577000004.jpg26117...(3)

[0094] Here, L is the contact length of the tire 111. The contact length L is the climb-over distance (x2-x1) in Figures 9A and 9B. The graph in Figure 9B shows an example of the change in the trajectory angle θ when the basic vehicle 100A climbs over a step ST as in Figure 9A.

[0095] "X1" shown in Figures 9A and 9B is the position of the base vehicle 100A when the tire 111 etc. contacts the step ST. Also, "X2" shown in Figures 9A and 9B is the position of the vehicle 100 when the tire 111 etc. leaves the road surface. This position corresponds to the inflection point in the graph of Figure 9A and the peak value in the graph of Figure 9B.

[0096] The "climbing distance" is the distance from X1 to X2, that is, the distance traveled by the basic vehicle 100A from when the tire 111 etc. contacts the step ST until the tire 111 etc. leaves the road surface. In other words, the "climbing distance" can be said to be the distance traveled by the vehicle 100 during the period from when the trajectory angle θ starts to increase to when it starts to decrease.

[0097] The climb-up distance defined in this manner correlates with the length (L1 in FIG. 8) of the portion of the tire 111, etc., that is in contact with the road surface RD when the basic vehicle 100A is parked on the flat road surface RD. For this reason, the lower the air pressure of the tire 111, etc., the longer L1 shown in FIG. 8 becomes, and the climb-up distance shown in FIGS. 9A and 9B also tends to become longer.

[0098] If the tire 111 is an ideal disk, the height h of the step ST can be calculated by the following formula.

[0099] JPEG2025066577000005.jpg35118...(4)

[0100] Here, θ in the above equation (4) is set to θ, which is the maximum value of the trajectory angle θ. max Then, the maximum height of the step ST is h max can be calculated.

[0101] Trajectory angle θ max can be calculated by the following formula:

[0102] θ max = κ × L (5)

[0103] Here, κ is the rate of change of the trajectory angle θ, and can be calculated by the following formula.

[0104] JPEG2025066577000006.jpg26131...(6)

[0105] Here, filter() is a function that performs a filter process to attenuate high-frequency components, and has a function of smoothing, i.e., easing, the amount of change in the trajectory angle θ. x is the vehicle speed.

[0106] From the above, the maximum height of the step ST is h max can be calculated by the following formula:

[0107] JPEG2025066577000007.jpg18134...(7)

[0108] In the following, the maximum height of the step ST is h max is simply referred to as the height h of the step ST.

[0109] In step S301, the CPU 21A executes a one-wheel or two-wheel climbing determination process shown in FIG.

[0110] As shown in Fig. 10, in step S400, the CPU 21A judges whether the step height h calculated in step S300 in Fig. 7 is equal to or less than a predetermined height. In this embodiment, the predetermined height is set to 2 cm as an example, but is not limited to this. If the step height h is equal to or less than the predetermined height, the process proceeds to step S401, and if the step height h is higher than the predetermined height, the process proceeds to step S402.

[0111] In step S401, a flag XKATARIN, which indicates whether one wheel or both wheels are attempting to go over a step ST, is set to 0. When the flag XKATARIN is 0, it indicates that both wheels are attempting to go over a step ST, and when the flag XKATARIN is 1, it indicates that one wheel is attempting to go over a step ST.

[0112] In step S402, the CPU 21A calculates a lateral G proportional value δ according to the following equation.

[0113] JPEG2025066577000008.jpg2779...(8)

[0114] Here, G y is the lateral G, that is, the acceleration in the left-right direction of the basic vehicle 100A, and can be obtained from the lateral acceleration sensor 95. K is a predetermined coefficient. Also, V x is the vehicle speed, r is the yaw rate, which can be obtained from a yaw rate sensor (not shown), and const is a predetermined coefficient for preventing the denominator from becoming zero.

[0115] When one wheel climbs over the step ST, the vehicle 100 tilts more than when both wheels climb over it, and this is detected as lateral G. Also, in order to cancel the lateral G generated when the basic vehicle 100A turns, it is determined whether one wheel or both wheels are attempting to climb over the step ST based on a lateral G proportional value δ obtained by comparing the lateral G with the lateral G calculated from the yaw rate r.

[0116] In step S403, CPU 21A determines whether the absolute value of lateral G proportional value δ calculated in step S402 is greater than a predetermined value, and if the absolute value of lateral G proportional value δ is greater than the predetermined value, proceeds to step S404, and if the absolute value of lateral G proportional value δ is equal to or less than the predetermined value, proceeds to step S401.

[0117] In step S404, the CPU 21A sets the flag XKATARIN to 1.

[0118] Returning to Fig. 7, in step S302, the CPU 21A determines whether or not the flag XKATARIN is 0. That is, it determines whether or not both wheels are about to climb over a step ST. If the flag XKATARIN is 0, this routine is terminated, and if the flag XKATARIN is 1, the process proceeds to step S303.

[0119] In step S303, the CPU 21A doubles the height h of the step ST according to the following formula: That is, when one wheel is going over the step ST, the height h of the step ST is set to double.

[0120] h = h × 2 (9)

[0121] Next, the details of the vehicle stop and travel restart determination process in step S204 in FIG. 6 will be described with reference to FIG.

[0122] In step S500, the CPU 21A judges whether the low-speed running control flag is ON. That is, it judges whether the execution of the low-speed running control in the manufacturing factory is permitted. Then, if the low-speed running control flag is ON, that is, if the execution of the low-speed running control in the manufacturing factory is permitted, the process proceeds to step S501, and if the low-speed running control flag is OFF, that is, if the execution of the low-speed running control in the manufacturing factory is not permitted, the process proceeds to step S503.

[0123] In step S501, the CPU 21A judges whether the height h of the step ST is higher than a first predetermined height. In the present embodiment, the first predetermined height is set to 13.5 cm as an example, but is not limited to this. If the height h of the step ST is higher than the first predetermined height, the process proceeds to step S502, and if the height h of the step ST is equal to or less than the first predetermined height, the process proceeds to step S504.

[0124] In step S502, the CPU 21A executes the vehicle stop control shown in FIG.

[0125] As shown in FIG. 12, in step S600, the CPU 21A sets the target vehicle speed to 0 kph.

[0126] In step S601, the CPU 21A calculates a feedback drive torque Tfb for performing PI feedback control so that the vehicle speed becomes the target vehicle speed set in step S600, that is, 0 kph, by the following equation.

[0127] JPEG2025066577000009.jpg1357...(10)

[0128] Here, e is the difference between the target vehicle speed and the actual vehicle speed. The actual vehicle speed can be obtained from the wheel speed sensors 81, 82. Kp is a proportional gain. Ki is an integral gain. Furthermore, Tfb is limited between a predetermined upper limit value and a predetermined lower limit value. The upper limit value is set to a value that provides a torque that does not cause injury even if a person collides with the basic vehicle 100A, for example. This ensures the safety of the worker. Note that, instead of the above equation (9), an equation for PD feedback control or an equation for PID feedback control may be used.

[0129] In step 602, the CPU 21A calculates a step correction torque TL that cancels the load torque according to the height h of the step ST, using the following equation.

[0130] TL = R × Fz × tan(θ) (11)

[0131] Here, since the target vehicle speed is 0 kph, the step correction torque TL is set to 0.

[0132] In step S603, the CPU 21A calculates the required torque T MG is calculated by the following formula and output to the inverter 96.

[0133] T MG =Tfb+TL+T slope (12)

[0134] Here, T slope is a gradient torque that is set according to the gradient of the road surface and is calculated by the following equation (13).

[0135] T slope = m × g × LPF(G x -G vspd , 0.5Hz) × R ··· (13)

[0136] Here, m is the current weight of the base vehicle 100A, and is obtained in step S300 of FIG. 7. g is the gravitational acceleration. x is the acceleration in the longitudinal direction of the basic vehicle 100A. vspd is the wheel acceleration calculated from the wheel speed detected by the wheel speed sensor 81 etc. R is the dynamic radius of the tire. LPF() is a low pass filter, and 0.5 Hz is the cutoff frequency.

[0137] In addition, the vehicle control device 2 outputs the gradient torque T slope In addition, when it is known in advance that the road surface on which the basic vehicle 100A is traveling has no gradient, the gradient torque T slope The calculation of may be omitted.

[0138] Returning to Fig. 11, in step S503, the CPU 21A sets the low-speed running flag XEX, which indicates whether the base vehicle 100A is running at a low speed, to OFF. When the low-speed running flag XEX is ON, it indicates that the base vehicle 100A is running at a low speed. On the other hand, when the low-speed running flag XEX is OFF, it indicates that the base vehicle 100A is stopped.

[0139] In step S504, the CPU 21A judges whether the height h of the step ST is higher than the second predetermined height. The second predetermined height is set to a height lower than the first predetermined height, and in this embodiment, it is set to 6.5 cm as an example, but is not limited to this. If the height h of the step ST is higher than the second predetermined height, the process proceeds to step S505, and if the height h of the step ST is equal to or lower than the second predetermined height, the routine ends.

[0140] In step S505, the CPU 21A determines whether or not the low speed travel flag XEX is OFF and Δθ is greater than a predetermined value, where Δθ is the amount of change in the trajectory angle θ per unit time.

[0141] 9B, the degree of increase in the trajectory angle θ from when the tire 111 etc. contacts the step ST at time X1 until when it leaves the road surface at time X2, that is, when attempting to go over the step ST, is relatively gradual. In contrast, for example, when the vehicle management device 2 issues an instruction to stop the vehicle and the basic vehicle 100A that is stopped is pushed by hand to resume traveling, the trajectory angle θ increases rapidly, as shown in FIG.

[0142] Therefore, when the low-speed driving flag XEX is OFF and Δθ is greater than a predetermined value, it can be considered that during the manufacturing process, for example, the vehicle management device 2 has instructed the basic vehicle 100A to stop and the basic vehicle 100A has been stopped, and a worker has pushed the basic vehicle 100A with his hand to encourage it to resume driving.

[0143] Therefore, in step S505, if the low-speed travel flag XEX is OFF and Δθ is greater than the predetermined value, it is determined that the basic vehicle 100A has been pushed by an operator to restart travel, and the process proceeds to step S507. On the other hand, if the low-speed travel flag XEX is ON or Δθ is less than the predetermined value, the process proceeds to step S506.

[0144] In step S506, the CPU 21A determines whether the low-speed running flag XEX is ON and Δθ is greater than a predetermined value. If an operator manually pushes the base vehicle 100A while it is running at a low speed to stop it for some reason during the manufacturing process, the trajectory angle θ increases rapidly, similar to when the base vehicle 100A is restarted while stopped.

[0145] Therefore, when the low-speed driving flag XEX is ON and Δθ is greater than a predetermined value, it can be assumed that during the manufacturing process, while the base vehicle 100A is traveling at a low speed, a worker is trying to stop the base vehicle 100A by pushing it with his or her hand for some reason.

[0146] Therefore, if the low-speed travel flag XEX is ON and Δθ is greater than a predetermined value, it is determined that the basic vehicle 100A is traveling at a low speed and an operator is trying to stop the basic vehicle 100A by pushing it by hand for some reason, and the process proceeds to step S502. On the other hand, if the low-speed travel flag XEX is OFF or Δθ is equal to or less than the predetermined value, the process proceeds to step S507.

[0147] In step S507, the CPU 21A executes low-speed crossing control. The low-speed crossing control is basically the same as the stop control in Fig. 12, but the target vehicle speed set in step S600 is different. In the low-speed crossing control, the target vehicle speed obtained from the vehicle management device 2 in step S200 in Fig. 6, for example, 1 kph, is set.

[0148] In step S508, the CPU 21A sets the low speed running flag XEX, which indicates whether the base vehicle 100A is running at a low speed, to ON.

[0149] As described above, in this embodiment, in the manufacturing process of the vehicle 100, the wheel speed of the tires 111 of the base vehicle 100A that can run automatically using the motor 89 or the like as a drive source is obtained from the wheel speed sensor 81 or the like, and the required torque T for running the base vehicle 100A at a low speed is calculated based on the obtained wheel speed. MG Calculate the required torque T MG The motor 89 and the like are controlled to be driven.

[0150] This allows the vehicle 100 to be manufactured by assembling parts while the basic vehicle 100A is running autonomously, thereby making it possible to improve the production efficiency of the vehicle 100.

[0151] The present disclosure is not limited to the above-described embodiments, and various modifications and applications are possible without departing from the gist of the present disclosure.

[0152] The configuration of the driving control device 10 described in the above embodiment (see FIG. 1) is just one example, and it goes without saying that unnecessary parts may be deleted and new parts may be added without departing from the spirit of the present disclosure.

[0153] Furthermore, the processing flow of the driving control program 23A described in the above embodiment (see Figures 5 to 7, 10 to 12) is also one example, and it goes without saying that unnecessary steps may be deleted, new steps may be added, or the processing order may be rearranged within the scope of the present disclosure.

[0154] The control unit and the method described herein may be implemented by a special-purpose computer having a processor programmed to execute one or more functions embodied in a computer program. Alternatively, the device and the method described herein may be implemented by a special-purpose computer having a processor configured by dedicated hardware logic circuits. Alternatively, the device and the method described herein may be implemented by one or more special-purpose computers configured by a combination of a processor that executes a computer program and one or more hardware logic circuits. The computer program may also be stored in a computer-readable non-transitory tangible recording medium as instructions to be executed by the computer.

[0155] The following notes are disclosed regarding the technology of the present disclosure.

[0156] <Additional Notes> (Appendix 1) a wheel speed acquisition unit (30) that acquires wheel speeds of tires (111, 112, 121, 122) of a basic vehicle (100A) that is capable of self-propelling using a motor (89, 90) as a drive source during a manufacturing process of the vehicle (100); a torque control unit (31) that calculates a required torque for running the base vehicle at a low speed based on the acquired wheel speed, and controls the motor to be driven with the calculated required torque; A driving control device (10) equipped with the same. (Appendix 2) The basic vehicle includes at least a drive unit (101, 102) in which the motor, an inverter (96, 97) for driving the motor, and a reduction gear (85, 86) for reducing the rotation speed of the motor are integrated, a battery (110) for supplying power to the inverter, and the driving control device. 2. The driving control device according to claim 1. (Appendix 3) a step estimation unit (32) that estimates the height of a step with which the tire is in contact; a determination unit (33) that determines at least one of whether or not the base vehicle has been pushed to cause the base vehicle to automatically travel while stopped, and whether or not the base vehicle has been pushed to stop the base vehicle while automatically traveling, based on a change amount per unit time of a path angle, which is an angle that the path of the rotation center axis of the tire makes with respect to a road surface, and the height of the step, The torque control unit calculates the required torque for the base vehicle to automatically drive when it is determined that the base vehicle has been pushed in order to automatically drive the base vehicle while stopped, and calculates the required torque for stopping the base vehicle when it is determined that the base vehicle has been pushed in order to stop the base vehicle while automatically driving. 3. A driving control device according to claim 1 or 2. (Appendix 4) The torque control unit performs control to stop a diagnostic fail-safe function that performs an abnormality diagnosis of the vehicle before the basic vehicle is made to run automatically in the manufacturing process. 4. The driving control device according to claim 1 , (Appendix 5) a target vehicle speed acquisition unit (34) that acquires the low target vehicle speed from a vehicle management device (2); The torque control unit calculates a required torque for causing the base vehicle to travel at the acquired target vehicle speed. 5. The driving control device according to claim 1 . (Appendix 6) a steering angle acquisition unit (35) that acquires a steering angle from a vehicle management device; a steering angle control unit (36) that controls the steering angle of the base vehicle based on the acquired steering angle; 6. The travel control device according to any one of claims 1 to 5, comprising: (Appendix 7) a weight acquisition unit (37) that acquires a weight of the base vehicle transmitted from a vehicle management device every time a part is assembled to the base vehicle, The torque control unit calculates the required torque based on the weight of the base vehicle. 7. A driving control device according to any one of claims 1 to 6. (Appendix 8) The low speed is a speed of 1 kph or more and 2 kph or less. 8. The driving control device according to any one of claims 1 to 7. (Appendix 9) At least one processor (21A) In a vehicle manufacturing process, a wheel speed of a basic vehicle capable of automatic driving using a motor as a drive source is obtained; calculating a required torque for running the base vehicle at a low speed based on the acquired wheel speed, and controlling the motor to be driven at the calculated required torque; The driving control method includes the steps of: (Appendix 10) At least one processor has In a vehicle manufacturing process, a wheel speed of a basic vehicle capable of automatic driving using a motor as a drive source is obtained; calculating a required torque for running the base vehicle at a low speed based on the acquired wheel speed, and controlling the motor to be driven at the calculated required torque; A driving control program that causes a process including the above to be executed. (Appendix 11) A vehicle is manufactured by sequentially assembling parts to a base vehicle capable of automatic driving, the base vehicle being equipped with a driving control device according to any one of appendices 1 to 8, while the base vehicle is being automatically driven. A method for manufacturing a vehicle. [Explanation of symbols]

[0157] 2 vehicle management device, 3 camera, 4 network, 10 driving control device, 21 control unit, 23 memory unit, 23A driving control program, 30 wheel speed acquisition unit, 31 torque control unit, 32 step estimation unit, 33 judgment unit, 34 target vehicle speed acquisition unit, 35 steering angle acquisition unit, 36 steering angle control unit, 37 weight acquisition unit, 81, 82, 83, 84 wheel speed sensor, 85, 86 reduction gear, 89, 90 motor, 96, 97 inverter, 100 vehicle, 100A basic vehicle, 101, 102 drive unit, 110 battery, 111, 112, 121, 122 tire

Claims

1. a wheel speed acquisition unit (30) that acquires wheel speeds of tires (111, 112, 121, 122) of a basic vehicle (100A) that is capable of automatic travel using a motor (89, 90) as a drive source during a manufacturing process of the vehicle (100); a torque control unit (31) that calculates a required torque for running the base vehicle at a low speed based on the acquired wheel speed, and controls the motor to be driven with the calculated required torque; A driving control device (10) equipped with the device.

2. The basic vehicle includes at least a drive unit (101, 102) in which the motor, an inverter (96, 97) for driving the motor, and a reduction gear (85, 86) for reducing the rotation speed of the motor are integrated, a battery (110) for supplying power to the inverter, and the driving control device. The cruise control device according to claim 1.

3. a step estimation unit (32) for estimating the height of a step with which the tire is in contact; a determination unit (33) that determines at least one of whether or not the base vehicle has been pushed to cause the base vehicle to automatically travel while stopped, and whether or not the base vehicle has been pushed to stop the base vehicle during automatic travel, based on a change amount per unit time of a path angle, which is an angle that the path of the rotation axis of the tire makes with respect to a road surface, and the height of the step, The torque control unit calculates the required torque for the base vehicle to automatically drive when it is determined that the base vehicle has been pushed in order to automatically drive the base vehicle while stopped, and calculates the required torque for stopping the base vehicle when it is determined that the base vehicle has been pushed in order to stop the base vehicle while automatically driving. The cruise control device according to claim 1.

4. The torque control unit performs control to stop a diagnostic fail-safe function that performs an abnormality diagnosis of the vehicle before the basic vehicle is made to run automatically in the manufacturing process. The cruise control device according to claim 1.

5. A target vehicle speed acquisition unit (34) is provided for acquiring the low target vehicle speed from a vehicle management device (2), The torque control unit calculates a required torque for causing the base vehicle to travel at the acquired target vehicle speed. The cruise control device according to claim 1.

6. A steering angle acquisition unit (35) that acquires a steering angle from a vehicle management device; A steering angle control unit (36) that controls the steering angle of the base vehicle based on the acquired steering angle; The travel control device according to claim 1 , further comprising:

7. a weight acquisition unit (37) that acquires a weight of the base vehicle transmitted from a vehicle management device every time a part is assembled to the base vehicle, The torque control unit calculates the required torque based on the weight of the base vehicle. The cruise control device according to claim 1.

8. The low speed is equal to or higher than 1 kph and equal to or lower than 2 kph. The cruise control device according to claim 1.

9. At least one processor (21A) In a vehicle manufacturing process, a wheel speed of a basic vehicle capable of automatic driving using a motor as a drive source is obtained; calculating a required torque for running the base vehicle at a low speed based on the acquired wheel speed, and controlling the motor to be driven at the calculated required torque; The driving control method includes the steps of:

10. At least one processor, In a vehicle manufacturing process, a wheel speed of a basic vehicle capable of automatic driving using a motor as a drive source is obtained; calculating a required torque for running the base vehicle at a low speed based on the acquired wheel speed, and controlling the motor to be driven at the calculated required torque; A driving control program that causes a process including the above to be executed.

11. A vehicle is manufactured by sequentially assembling parts to a base vehicle capable of automatically traveling, the base vehicle being equipped with the travel control device according to any one of claims 1 to 8, while the base vehicle is automatically traveling. A method for manufacturing a vehicle.

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