Monitoring device

Abstract

To appropriately detect a speed of a vehicle even during low-speed travel in synchronization with a transport speed of a conveyor.SOLUTION: A monitoring device being a monitoring device for monitoring a vehicle that travels autonomously using an electric motor as a power source, includes: a selection unit which selects one of a first method that acquires the vehicle speed using a detection value from a vehicle speed sensor that performs the output in synchronization with the rotation of wheels of the vehicle and a second method that acquires the vehicle speed using information related to the rotational speed of the electric motor installed in the vehicle, to acquire the vehicle speed according to the situation related to the vehicle speed; and a speed acquisition unit which acquires the vehicle speed through the method selected by the selection unit.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a monitoring device.

Background Art

[0002] Patent Document 1 describes a vehicle that is the object of manufacturing and travels remotely or autonomously in a manufacturing process for manufacturing a vehicle.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a manufacturing process, by running an unfinished vehicle, the unfinished vehicle may be moved between processes without using a conveyor. The unfinished vehicle travels at an extremely low speed in accordance with the conveyance speed of the conveyor. The inventors have found that when the traveling speed of the vehicle is extremely low, the reliability of the detection value of the vehicle speed sensor is low. For this reason, a technology capable of appropriately detecting the speed of the vehicle has been demanded even during low-speed traveling in accordance with the conveyance speed of the conveyor.

Means for Solving the Problems

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to the first aspect of the present disclosure, a monitoring device is provided. The monitoring device is a monitoring device that monitors a vehicle that travels by autonomous driving using an electric motor as a power source, and uses a detection value of a vehicle speed sensor that outputs in synchronization with the rotation of the wheels of the vehicle to obtain the speed of the vehicle. A first method, and a second method of obtaining the speed of the vehicle using information regarding the rotational speed of the electric motor provided in the vehicle, and according to the situation regarding the speed of the vehicle, any one of the methods is used to obtain the speed of the vehicle. And a speed acquisition unit that acquires the speed of the vehicle by the method selected by the selection unit. According to this aspect, whether to use the detection value of the vehicle speed sensor or the information regarding the rotational speed of the electric motor to obtain the speed of the vehicle is selected according to the situation regarding the speed of the vehicle. Therefore, whether the vehicle is traveling at a low speed or not, the speed of the vehicle can be appropriately detected. (2) In the monitoring device of the above aspect, when a predetermined condition indicating that the detection value of the vehicle speed sensor is highly reliable is satisfied, the selection unit selects the first method, and when the condition is not satisfied, The second method may be selected. According to this aspect, when the detection value of the vehicle speed sensor is highly reliable, the speed of the vehicle is obtained using the detection value of the vehicle speed sensor, and when the detection value of the vehicle speed sensor is not highly reliable, the rotational speed of the electric motor is used. The speed of the vehicle is obtained using the related information. Therefore, the reliability of detecting the speed of the vehicle can be ensured whether the vehicle is traveling at a low speed or not. (3) In the monitoring device of the above aspect, the condition may include indicating that the detection value of the vehicle speed sensor is equal to or higher than a predetermined speed. According to this aspect, since the higher the speed of the vehicle, the higher the reliability of the detection value of the vehicle speed sensor tends to be, the speed of the vehicle can be appropriately detected. (4) In the monitoring device of the above aspect, the vehicle is a vehicle that travels in a factory where a plurality of processes are executed to manufacture the vehicle, and the condition is that the vehicle is traveling in the current process of the vehicle. It may include that there is no speed limit. According to this embodiment, for a vehicle traveling in a factory, when a speed limit is imposed on the vehicle in a specific process, the vehicle will travel at a low speed. Therefore, the speed of the vehicle is obtained using information regarding the rotational speed of the electric motor. Thus, even when the vehicle is traveling at a low speed, the speed of the vehicle can be appropriately detected. (5) In the monitoring device according to the above embodiment, when the first method is selected, the control value for controlling the driverless operation of the vehicle may include at least a target value of the acceleration of the vehicle. (6) In the monitoring device according to the above embodiment, when the second method is selected, the control value for controlling the driverless operation of the vehicle may include at least a target value of the speed of the vehicle. According to this embodiment, due to disturbances caused by the driving environment of the vehicle, accelerations in the longitudinal direction and the lateral direction are applied to the vehicle. When the speed of the vehicle is equal to or higher than a predetermined speed, the changes in the accelerations in the longitudinal direction and the lateral direction tend to increase. Therefore, due to the changes in the accelerations in the longitudinal direction and the lateral direction, the driving of the vehicle may become unstable. Thus, by controlling the acceleration of the vehicle, the driving of the vehicle can be finely controlled.

[0007] Note that the present disclosure can be realized in various forms. For example, it can be realized in the forms of a remote operation system, a movement control device, a remote automatic driving method, and a manufacturing method of a moving body.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0009] A. First Embodiment: FIG. 1 is a conceptual diagram showing the configuration of the system 50 in the first embodiment. The system 50 is used in a factory FC that manufactures the vehicle 100. The vehicle 100 is a battery electric vehicle (BEV). The vehicle 100 runs using an electric motor as a power source. Also, the vehicle 100 is the subject of a plurality of processes executed at the factory FC. The system 50 includes one or more vehicles 100 as moving bodies, a server 200, and a plurality of external sensors 300. The server 200 is also referred to as a “monitoring device”. The external sensor 300 is a camera that photographs the vehicle 100. In the present disclosure, a “moving body” means an object that can move, for example, a vehicle or an electric vertical takeoff and landing aircraft (so-called flying car). The vehicle may be a vehicle that runs on wheels or a vehicle that runs on an endless track, for example, a passenger car, a truck, a bus, a two-wheeled vehicle, a four-wheeled vehicle, a tank, a construction vehicle, etc. The vehicle includes a battery electric vehicle (BEV), a gasoline vehicle, a hybrid vehicle, and a fuel cell vehicle. When the moving body is other than a vehicle, the expressions “vehicle” and “car” in the present disclosure can be appropriately replaced with “moving body”, and the expression “running” can be appropriately replaced with “moving”.

[0010] Vehicle 100 can travel through autonomous driving. "Autonomous driving" means driving without relying on the driving operations of passengers. The driving operation means an operation related to at least one of "driving forward", "turning", and "stopping" of Vehicle 100. Autonomous driving is realized by automatic or manual remote control using a device located outside Vehicle 100, or by the autonomous control of Vehicle 100. A passenger who does not perform a driving operation may board Vehicle 100 while it is traveling through autonomous driving. Passengers who do not perform a driving operation include, for example, a person simply sitting on the seat of Vehicle 100, or a person performing work different from driving operations, such as assembly, inspection, and operation of switches, while boarding Vehicle 100. Note that driving by the driving operation of a passenger may be called "human-driven".

[0011] In this specification, "remote control" includes "full remote control" in which all the operations of Vehicle 100 are completely determined from outside Vehicle 100, and "partial remote control" in which a part of the operations of Vehicle 100 is determined from outside Vehicle 100. Also, "autonomous control" includes "full autonomous control" in which Vehicle 100 autonomously controls its own operations without receiving any information from a device outside Vehicle 100, and "partial autonomous control" in which Vehicle 100 autonomously controls its own operations using the information received from a device outside Vehicle 100.

[0012] Vehicle 100 is in a state during manufacturing and travels through factory FC where Vehicle 100 is manufactured by autonomous driving. The reference coordinate system of factory FC is the global coordinate system GC. That is, any position within factory FC is represented by the coordinates of X, Y, and Z in the global coordinate system GC. Factory FC includes a first location PL1, a second location PL2, and a third location PL3. The first location PL1, the second location PL2, and the third location PL3 are connected by a runway TR on which Vehicle 100 can travel. A plurality of external sensors 300 are installed along the runway TR in factory FC. The positions of each external sensor 300 in factory FC are adjusted in advance. Vehicle 100 moves from the first location PL1 to the second location PL2 through the runway TR by autonomous driving. Further, Vehicle 100 moves from the second location PL2 to the third location PL3 through the runway TR.

[0013] The first location PL1 is a place where the operation of assembling the vehicle 100 is carried out. For example, at the first location PL1, the operation of assembling parts is carried out by an assembly robot (not shown). The vehicle 100 assembled at the first location PL1 is in a state where it can run by autonomous driving, in other words, it is in a state where it can exhibit the three functions of "running", "turning", and "stopping" by autonomous driving. In the present embodiment, the vehicle 100 assembled at the first location PL1 travels from the first location PL1 to the second location PL2 by autonomous driving in the form of a platform having the configuration described below. Specifically, the vehicle 100 only needs to include at least a vehicle control device 110 and an actuator group 120 in order to exhibit the three functions of "running", "turning", and "stopping" by autonomous driving. When the vehicle 100 acquires information from the outside for autonomous driving, the vehicle 100 only needs to further include a communication device 130. That is, for the vehicle 100 that can move by autonomous driving, at least a part of the interior parts such as the driver's seat and dashboard may not be installed, at least a part of the exterior parts such as the bumper and fender may not be installed, and the body shell may not be installed. In this case, before the vehicle 100 is shipped from the factory FC, the remaining parts such as the body shell may be installed on the vehicle 100, or the vehicle 100 may be shipped from the factory FC in a state where the remaining parts such as the body shell are not installed on the vehicle 100, and then the remaining parts such as the body shell may be installed on the vehicle 100. Each part may be installed from any direction such as the upper side, lower side, front side, rear side, right side, or left side of the vehicle 100, and they may be installed from the same direction or from different directions respectively.

[0014] At the second location PL2, further parts are assembled to the vehicle 100 by an assembly robot (not shown). At the second location PL2, a body such as a body shell and a bonnet, interior parts such as seats and dashboards, and exterior parts such as bumpers and fenders are assembled to the vehicle 100 in the form of a platform by an assembly robot (not shown). At the third location PL3, functional parts are attached. The functional parts are, for example, a plurality of ECUs.

[0015] Figure 2 is a block diagram showing the schematic configuration of the system 50. The vehicle 100 includes a vehicle control device 110 for controlling each part of the vehicle 100, an actuator group 120 including one or more actuators driven under the control of the vehicle control device 110, a communication device 130 for communicating with an external device such as the server 200 by wireless communication, a vehicle speed sensor 140, and a rotation angle sensor 150. The actuator group 120 includes an actuator of a driving device for accelerating the vehicle 100, an actuator of a steering device for changing the traveling direction of the vehicle 100, and an actuator of a braking device for decelerating the vehicle 100.

[0016] The vehicle speed sensor 140 outputs a pulse signal in response to the rotation of the rotation axis of the wheel. The vehicle speed sensor 140 is a sensor that outputs in synchronization with the rotation of the wheels of the vehicle 100. The vehicle speed sensor 140 generates a pulse signal every time the rotation axis of the wheel rotates by a set angle such as 90 degrees or 180 degrees. The pulse signal output by the vehicle speed sensor 140 is also referred to as a vehicle speed pulse or a vehicle speed signal. The vehicle speed sensor 140 outputs the pulse signal to the processor 111.

[0017] The rotation angle sensor 150 detects the rotation angle of the output shaft of a motor (hereinafter referred to as a drive motor), which is an actuator that drives the drive shaft. As the rotation angle sensor 150, a resolver, an encoder, or the like is used. The rotation angle sensor 150 outputs a signal representing the detected rotation angle to the processor 111.

[0018] The vehicle control device 110 is configured by a computer including a processor 111, a memory 112, an input / output interface 113, and an internal bus 114. The processor 111, the memory 112, and the input / output interface 113 are connected to be communicable bidirectionally via the internal bus 114. An actuator group 120 and a communication device 130 are connected to the input / output interface 113. The processor 111 realizes various functions including functions as a vehicle control unit 115, a speed calculation unit 116, and a motor rotation speed calculation unit 117 by executing a program PG1 stored in the memory 112.

[0019] The vehicle control unit 115 can run the vehicle 100 by controlling the actuator group 120 using a travel control signal received from the server 200. The travel control signal is a control signal for running the vehicle 100. In the present embodiment, the travel control signal includes the acceleration and the steering angle of the vehicle 100 as parameters. Alternatively, the travel control signal may include the speed of the vehicle 100 as a parameter instead of or in addition to the acceleration of the vehicle 100.

[0020] Also, the vehicle control unit 115 periodically transmits the travel speed of the vehicle 100 calculated by the speed calculation unit 116 described later to the server 200. The vehicle control unit 115 periodically transmits the rotation speed of the output shaft of the drive motor calculated by the motor rotation speed calculation unit 117 described later to the server 200.

[0021] The speed calculation unit 116 calculates the travel speed of the vehicle 100 using a pulse signal received from the vehicle speed sensor 140.

[0022] The motor rotation speed calculation unit 117 calculates the rotation speed of the output shaft of the drive motor using a signal representing the rotation angle received from the rotation angle sensor 150.

[0023] The server 200 is constituted by a computer including a processor 201, a memory 202, an input / output interface 203, and an internal bus 204. The processor 201, the memory 202, and the input / output interface 203 are communicably connected bidirectionally via the internal bus 204. A communication device 205 for communicating with various external devices of the server 200 is connected to the input / output interface 203. The communication device 205 can communicate with the vehicle 100 by wireless communication and can communicate with each external sensor 300 by wired communication or wireless communication.

[0024] The memory 202 stores in advance a program PG2, a reference route RR indicating a route along which the vehicle 100 should travel, a detection model DM described later, and the like. By executing the program PG2 stored in the memory 202, the processor 201 realizes various functions including functions as a selection unit 210, a speed acquisition unit 230, a position estimation unit 240, and a remote control unit 250.

[0025] The selection unit 210 selects which of a first method and a second method to use as a method for acquiring the speed of the vehicle 100. The first method is a method of acquiring the speed of the vehicle 100 using the detection value of the vehicle speed sensor 140. The second method is a method of acquiring the speed of the vehicle 100 using the rotational speed of the output shaft of the drive motor of the vehicle 100 as information regarding the rotational speed of the drive motor provided in the vehicle 100.

[0026] The speed acquisition unit 230 acquires the detection value of the vehicle speed sensor 140 or the rotational speed of the output shaft of the drive motor of the vehicle 100 according to the method selected by the selection unit 210.

[0027] The position estimation unit 240 estimates the position and orientation of the vehicle 100 using the detection result output from the external sensor 300. Alternatively, the position estimation unit 240 may estimate only one of the position and orientation of the vehicle 100 using the detection result output from the external sensor 300. In this case, for example, the other of the position and orientation of the vehicle 100 is determined using the travel history of the vehicle 100 or the like.

[0028] The remote control unit 250 acquires the detection results from the sensors, generates a driving control signal for controlling the actuator group 120 of the vehicle 100 using the detection results, and transmits the driving control signal to the vehicle 100, thereby driving the vehicle 100 by remote control. The remote control unit 250 may generate and output not only the driving control signal but also, for example, control signals for controlling actuators that operate various auxiliary machines provided in the vehicle 100 and various equipment such as wipers, power windows, and lamps. That is, the remote control unit 250 may operate such various equipment and various auxiliary machines by remote control. In this specification, "remote control" includes "complete remote control" in which all of the operations of the vehicle 100 are completely determined from outside the vehicle 100 and "partial remote control" in which a part of the operations of the vehicle 100 is determined from outside the vehicle 100.

[0029] The external sensor 300 is a sensor located outside the vehicle 100. The external sensor 300 is a sensor that captures the vehicle 100 from outside the vehicle 100. The external sensor 300 includes a communication device (not shown) and can communicate with other devices such as the server 200 by wired communication or wireless communication. Specifically, the external sensor 300 is constituted by a camera installed within the premises of a factory. The camera as the external sensor 300 captures a captured image including the vehicle 100 and outputs the captured image as a detection result.

[0030] FIG. 3 is a flowchart showing the processing procedure for the driving control of the vehicle 100. The processing in FIG. 3 is executed by the processor 201 of the server 200 that functions as the position estimation unit 240 and the remote control unit 250, and the processor 111 of the vehicle 100 that functions as the vehicle control unit 115. The processing shown in FIG. 3 is repeatedly executed, for example, at predetermined time intervals from the time when the vehicle 100 starts driving by remote control.

[0031] In step 1, the processor 201 of the server 200 acquires the vehicle position information of the vehicle 100 by using the detection result output from the external sensor 300. The vehicle position information is the position information that serves as the basis for generating the driving control signal. In this embodiment, the vehicle position information includes the position and orientation of the vehicle 100 in the global coordinate system GC of the factory FC. Specifically, in step 1, the processor 201 acquires the vehicle position information by using the captured image obtained from the camera which is the external sensor 300.

[0032] Specifically, in step 1, the processor 201, for example, detects the outer shape of the vehicle 100 from the captured image, calculates the coordinates of the measurement points of the vehicle 100 in the coordinate system of the captured image, that is, the local coordinate system, and converts the calculated coordinates into the coordinates in the global coordinate system GC, thereby acquiring the position of the vehicle 100. The outer shape of the vehicle 100 included in the captured image can be detected, for example, by inputting the captured image into a detection model DM that utilizes artificial intelligence. The detection model DM is prepared, for example, inside or outside the system 50 and is stored in advance in the memory 202 of the server 200. Examples of the detection model DM include a learned machine learning model that is learned to realize either semantic segmentation or instance segmentation. As this machine learning model, for example, a convolutional neural network (hereinafter referred to as CNN) learned by supervised learning using a learning dataset can be used. The learning dataset has, for example, a plurality of training images including the vehicle 100 and a label indicating whether each region in the training image is a region indicating the vehicle 100 or a region indicating other than the vehicle 100. During the learning of the CNN, it is preferable that the parameters of the CNN are updated by backpropagation (error backpropagation method) so as to reduce the error between the output result by the detection model DM and the label. Also, the processor 201 can acquire the orientation of the vehicle 100, for example, by estimating based on the direction of the movement vector of the vehicle 100 calculated from the position change of the feature points of the vehicle 100 between the frames of the captured image by using the optical flow method.

[0033] In step 2, the processor 201 of the server 200 determines the target position to which the vehicle 100 should next head. In this embodiment, the target position is represented by the coordinates of X, Y, and Z in the global coordinate system GC. In the memory 202 of the server 200, a reference route RR, which is the route along which the vehicle 100 should travel, is pre-stored. The route is represented by a node indicating the starting point, a node indicating a passing point, a node indicating the destination, and links connecting each node. The processor 201 determines the target position to which the vehicle 100 should next head using the vehicle position information and the reference route RR. The processor 201 determines the target position on the reference route RR ahead of the current position of the vehicle 100.

[0034] In step 3, the processor 201 of the server 200 generates a driving control signal for driving the vehicle 100 toward the determined target position. The processor 201 calculates the driving speed of the vehicle 100 from the change in the position of the vehicle 100 and compares the calculated driving speed with the target speed. Overall, when the driving speed is lower than the target speed, the processor 201 determines the acceleration so that the vehicle 100 accelerates, and when the driving speed is higher than the target speed, the processor 201 determines the acceleration so that the vehicle 100 decelerates.

[0035] Also, when the vehicle 100 is located on the reference route RR, the processor 201 determines the steering angle and acceleration so that the vehicle 100 does not deviate from the reference route RR. When the vehicle 100 is not located on the reference route RR, in other words, when the vehicle 100 has deviated from the reference route RR, the processor 201 determines the steering angle and acceleration so that the vehicle 100 returns to the reference route RR.

[0036] In step 4, the processor 201 of the server 200 transmits the generated driving control signal to the vehicle 100. The processor 201 repeats obtaining the position of the vehicle 100, determining the target position, generating the driving control signal, and transmitting the driving control signal at a predetermined cycle.

[0037] In step 5, the processor 111 of the vehicle 100 receives the driving control signal transmitted from the server 200. In step 6, the processor 111 of the vehicle 100 controls the actuator group 120 using the received driving control signal, thereby driving the vehicle 100 at the acceleration and steering angle represented by the driving control signal. The processor 111 repeats the reception of the driving control signal and the control of the actuator group 120 at a predetermined cycle. According to the system 50 in this embodiment, the vehicle 100 can be driven by remote control, and the vehicle 100 can be moved without using conveying equipment such as a crane or a conveyor.

[0038] In this embodiment, the vehicle 100 in the manufacturing process state travels inside the factory FC. Among the plurality of processes executed on the vehicle 100, as described above, there is a process in which parts are assembled while the vehicle 100 itself travels without using a conveyor. In such a case, the running of the vehicle is controlled so that the running speed of the vehicle 100 becomes the same as the conveying speed of the conveyor.

[0039] When the remote control unit 250 generates a driving control signal for controlling the actuator group 120 of the vehicle 100, it is necessary to detect the speed of the vehicle 100 during running. Here, when the running speed of the vehicle 100 is low, the output interval of the pulse signal output by the vehicle speed sensor 140 is coarse. For this reason, since the resolution of the pulse signal becomes low, the detection accuracy of the speed of the vehicle obtained based on the pulse signal tends to be low.

[0040] Therefore, in this embodiment, as a method for obtaining the speed of the vehicle 100, a method selected from either the first method or the second method is used.

[0041] FIG. 4 is a flowchart showing a procedure for obtaining the speed of the vehicle 100. The process shown in FIG. 4 starts immediately after the vehicle 100 starts running. For example, when the process at the first location PL1 is carried out, the process shown in FIG. 4 is executed immediately after the vehicle 100, which has become in the form of a platform capable of autonomous driving, starts running. The process shown in FIG. 4 is executed by the processor 201 that functions as the selection unit 210, the speed acquisition unit 230, and the position estimation unit 240.

[0042] In step 11, the processor 201 identifies the current position of the vehicle 100. Here, the processor 201 acquires process information representing the current process where the vehicle 100 is located in order to identify the current position of the vehicle 100. For example, the processor 201 acquires process information representing the process where the vehicle 100 is located from a higher-level server (not shown). After each process is carried out, for example, it is assumed that the operator uses a terminal device to output a notification of the end of the process to the higher-level server. Therefore, the processor 201 can inquire of the higher-level server about the current process where the vehicle 100 is located. Also, the processor 201 may estimate the position of the vehicle 100 using the detection result output from the external sensor 300 in order to identify the current position of the vehicle 100. Alternatively, the processor 201 may identify the current position of the vehicle 100 using the process information supplied from the higher-level server and the detection result output from the external sensor 300.

[0043] In step 12, the processor 201 acquires information on the target speed of the vehicle 100. The target speed is the driving speed that the vehicle 100 should maintain when driving at the current position. For example, the processor 201 can acquire the target speed, which is the driving speed that the vehicle 100 should maintain at each point on the driving route to the target point, based on the speed profile. The speed profile defines the driving speed that the vehicle 100 should maintain at each point on the driving route to the target point. The speed profile is pre-stored in the memory 202. The processor 201 acquires information on the target speed at the current position based on the speed profile. It is assumed that the vehicle 100 is controlled to drive while maintaining the target speed.

[0044] In step 13, as a method for the processor 201 to acquire the speed of the vehicle 100, the processor 201 selects either the first method or the second method. As described above, the first method is a method of acquiring the speed of the vehicle 100 by using the detection value of the vehicle speed sensor 140. The second method is a method of acquiring the speed of the vehicle 100 by using the rotational speed of the output shaft of the drive motor of the vehicle 100 as information on the rotational speed of the drive motor provided in the vehicle 100.

[0045] In this embodiment, when the target speed obtained in step 12 is equal to or higher than a predetermined threshold value, the first method is selected. When the target speed obtained in step 12 is less than the predetermined threshold value, the second method is selected. The predetermined threshold value is, for example, 5 kilometers per hour. When the target speed is less than the predetermined threshold value, it is assumed that the vehicle 100 travels at a low speed. In the range less than the predetermined threshold value, the reliability of the traveling speed of the vehicle 100 calculated using the pulse signal output by the vehicle speed sensor 140 is low. The low speed refers to a speed at which the reliability of the traveling speed of the vehicle 100 calculated using the pulse signal output by the vehicle speed sensor 140 is less than a predetermined standard. The predetermined threshold value is set based on a speed at which the reliability of the traveling speed of the vehicle 100 calculated using the pulse signal output by the vehicle speed sensor 140 is less than a predetermined standard. Therefore, when the target speed is less than the predetermined threshold value, the second method is selected. When the target speed is equal to or higher than the predetermined threshold value, the first method is selected. The higher the speed of the vehicle 100, the higher the reliability of the detection value of the vehicle speed sensor 140 tends to be. For this reason, the speed of the vehicle 100 can be detected appropriately.

[0046] In step 14, when the first method is selected (step 14; YES), the process of step 15 is executed. On the other hand, when the first method is not selected, that is, when the second method is selected (step 14; NO), the process of step 16 is executed.

[0047] In step 15, the processor 201 obtains the speed of the vehicle 100 using the first method. The processor 201 obtains, as the traveling speed of the vehicle 100, the traveling speed calculated based on the pulse signal of the vehicle speed sensor 140 transmitted from the vehicle control unit 115. The obtained traveling speed of the vehicle 100 is used when generating a traveling control signal (see step 3 in FIG. 3).

[0048] In step 16, the processor 201 obtains the speed of the vehicle 100 using the second method. The processor 201 obtains the rotational speed of the output shaft of the drive motor transmitted from the vehicle control unit 115. Further, the processor 201 calculates the traveling speed of the vehicle 100 using the obtained rotational speed of the output shaft of the drive motor. The obtained traveling speed of the vehicle 100 is used when generating the traveling control signal (see step 3 in FIG. 3).

[0049] If the vehicle 100 has not finally reached the destination (step 17; NO), the process of step 11 is executed again. If the vehicle 100 has finally reached the destination (step 17; YES), the process of FIG. 4 is terminated.

[0050] In the present embodiment, when the reliability of the detection value of the vehicle speed sensor 140 is not high, the speed of the vehicle is obtained using information regarding the rotational speed of the electric motor. When the reliability of the detection value of the vehicle speed sensor 140 is not high, it includes the case where the vehicle 100 travels at a low speed. When the target speed of the vehicle 100 at the current position is low, the speed of the vehicle is obtained using information regarding the rotational speed of the drive motor. Also, when the reliability of the detection value of the vehicle speed sensor 140 is high, the speed of the vehicle is obtained using the detection value of the vehicle speed sensor 140.

[0051] As described above, when the traveling speed of the vehicle 100 is low, the resolution of the pulse signal output by the vehicle speed sensor 140 decreases. For this reason, the detection accuracy of the speed of the vehicle obtained based on the pulse signal tends to be low. On the other hand, when the traveling speed of the vehicle 100 is not low, the accuracy of the speed obtained based on the pulse signal output by the vehicle speed sensor 140 is higher than the accuracy of the speed obtained using the information regarding the rotational speed of the drive motor. This is because the vehicle speed sensor 140 directly reads the rotation of the wheels of the vehicle 100. The method of obtaining the speed based on the rotational speed of the drive motor does not directly detect the rotation of the wheels of the vehicle 100. Further, the rotational speed of the drive motor may include uncertain factors such as the occurrence of backlash and play of the gears of the vehicle 100, the change of the shift and the neutral range, and the rotational difference between the left and right tires during turning. For this reason, in the present embodiment, in a limited scenario where the vehicle 100 travels at a low speed, such as when the vehicle 100 in the manufacturing process travels at the same speed as the conveyance speed of the conveyor, and when the reliability of the detection value of the vehicle speed sensor 140 is not high, the speed of the vehicle is obtained using the information regarding the rotational speed of the drive motor.

[0052] As described above, it is possible to ensure the reliability of the detection of the speed of the vehicle both when traveling at a low speed and when not traveling at a low speed. Thus, whether to use the detection value of the vehicle speed sensor 140 or the information regarding the rotational speed of the drive motor to obtain the speed of the vehicle 100 is selected according to the situation regarding the speed of the vehicle 100. Therefore, it is possible to appropriately detect the speed of the vehicle both when traveling at a low speed and when not traveling at a low speed.

[0053] B. Second Embodiment: FIG. 5 is an explanatory diagram showing a schematic configuration of the system 50v in the second embodiment. In this embodiment, the system 50v is different from the first embodiment in that it does not include the server 200. Also, the vehicle 100v in this embodiment can travel by autonomous control of the vehicle 100v. Regarding other configurations, unless otherwise specified, they are the same as those in the first embodiment. The vehicle control device 110v is composed of a computer including a processor 111v, a memory 112v, an input / output interface 113, and an internal bus 114. Hereinafter, the description will focus on the configurations different from those in the first embodiment, and the description of the same configurations as those in the first embodiment will be omitted.

[0054] The memory 112v stores in advance a program PG1v, a reference route RR indicating the route along which the vehicle 100v should travel, a detection model DM, and the like.

[0055] In this embodiment, the processor 111v of the vehicle control device 110v functions as a vehicle control unit 115v, a speed calculation unit 116, a motor rotation speed calculation unit 117, a position estimation unit 123, a selection unit 128, and a speed acquisition unit 129 by executing the program PG1v stored in the memory 112v.

[0056] The position estimation unit 123 estimates the position and orientation of the vehicle 100v using the detection results output from the external sensor 300. Note that the communication device 130 can communicate with each external sensor 300 by wired communication or wireless communication. Alternatively, the position estimation unit 123 may estimate only one of the position and orientation of the vehicle 100v using the detection results output from the external sensor 300. In this case, for example, the other of the position and orientation of the vehicle 100v is determined using the driving history of the vehicle 100v or the like.

[0057] The vehicle control unit 115v can obtain the output results from the sensors, generate a driving control signal using the output results, output the generated driving control signal, and operate the actuator group 120 to make the vehicle 100v travel by autonomous control.

[0058] The functions of the speed calculation unit 116 and the motor rotation speed calculation unit 117 are the same as those in the first embodiment.

[0059] Similar to the selection unit 210 in the first embodiment, the selection unit 128 selects which of the first method and the second method to use as a method for acquiring the speed of the vehicle 100v. The first method and the second method are the same as those in the first embodiment.

[0060] Similar to the speed acquisition unit 230 in the first embodiment, the speed acquisition unit 129 acquires the speed of the vehicle 100v by the method selected by the selection unit 210.

[0061] FIG. 6 is a flowchart showing the processing procedure of the running control of the vehicle 100v in the second embodiment. The processor 111v functioning as the position estimation unit 123 and the vehicle control unit 115v executes the processing of FIG. 6.

[0062] In step 101, the processor 111v acquires vehicle position information using the detection result output from the camera which is the external sensor 300. In step 102, the processor 111v determines the target position to which the vehicle 100v should next head. In step 103, the processor 111v generates a running control signal for running the vehicle 100v toward the determined target position. In step 104, the processor 111v controls the actuator group 120 using the generated running control signal, thereby running the vehicle 100v according to the parameters represented in the running control signal. The processor 111v repeats the acquisition of vehicle position information, determination of the target position, generation of the running control signal, and control of the actuator at a predetermined cycle. According to the system 50v in the present embodiment, the vehicle 100v can be run by the autonomous control of the vehicle 100v without remotely controlling the vehicle 100v by the server 200.

[0063] FIG. 7 is a flowchart showing a procedure for obtaining the speed of vehicle 100v. The process shown in FIG. 7 starts immediately after vehicle 100v starts running. For example, when the process at the first location PL1 is performed, the process shown in FIG. 7 is executed immediately after vehicle 100v, which has become a form of a platform capable of autonomous driving, starts running. The process shown in FIG. 7 is executed by a processor 111v that functions as a selection unit 128, a speed acquisition unit 129, and a position estimation unit 123.

[0064] In step 211, the processor 111v identifies the current position of vehicle 100v. Here, the processor 111v acquires process information representing the current process in which vehicle 100v is located in order to identify the current position of vehicle 100v. For example, the processor 111v acquires process information representing the process in which vehicle 100v is located from a higher-level server (not shown). Also, the processor 201 may estimate the position of vehicle 100v using the detection result output from the external sensor 300 in order to identify the current position of vehicle 100v. Alternatively, the processor 201 may identify the current position of vehicle 100v using the process information supplied from the higher-level server and the detection result output from the external sensor 300.

[0065] In step 212, the processor 111v acquires information on the target speed of vehicle 100v. For example, the processor 111v acquires information on the target speed at the current position based on the speed profile. The speed profile is stored in advance in the memory 112v.

[0066] In step 213, the processor 111v selects either the first method or the second method as a method for acquiring the speed of vehicle 100v.

[0067] In this embodiment, the processor 111v uses the process information acquired in step 211 to determine whether or not there is a speed limit imposed on the traveling speed in the current process where the vehicle 100v is located. It is assumed that the process information includes information indicating the process where the vehicle 100v is located, as well as information on whether or not there is a speed limit imposed on the traveling speed in that process. That there is a speed limit imposed on the traveling speed means that the vehicle 100v must travel at or below a predetermined speed. For example, when a plurality of workers assemble a plurality of parts on the vehicle 100v in the process, a speed limit is imposed on the traveling speed of the vehicle 100v. The predetermined speed is, for example, 3 kilometers per hour. When a speed limit is imposed on the traveling speed of the vehicle 100v, it is assumed that the vehicle 100v travels at a low speed. The predetermined speed is set based on a speed at which the reliability of the traveling speed of the vehicle 100 calculated using the pulse signal output by the vehicle speed sensor 140 is less than a predetermined standard. When there is a speed limit imposed on the traveling speed in the current process where the vehicle 100v is located, the processor 111v selects the second method as the method for acquiring the speed of the vehicle 100v. When the vehicle 100v is traveling at a low speed, the reliability of the traveling speed of the vehicle 100v calculated using the pulse signal output by the vehicle speed sensor 140 is low. Therefore, the second method is selected. Also, when there is no speed limit imposed on the traveling speed in the current process where the vehicle 100v is located, the processor 111v selects the first method as the method for acquiring the speed of the vehicle 100v.

[0068] In step 214, when the first method is selected (step 214; YES), the process of step 215 is executed. On the other hand, when the first method is not selected, that is, when the second method is selected (step 214; NO), the process of step 216 is executed.

[0069] In step 215, the processor 111v obtains the speed of the vehicle 100v using the first method. The processor 111v obtains the traveling speed calculated based on the pulse signal output by the vehicle speed sensor 140 as the traveling speed of the vehicle 100v. The obtained traveling speed of the vehicle 100v is used when generating a traveling control signal (see step 103 in FIG. 6).

[0070] In step 216, the processor 111v obtains the speed of the vehicle 100v using the second method. The processor 111v calculates the traveling speed of the vehicle 100v using the rotational speed of the output shaft of the drive motor calculated from the rotation angle of the drive motor output by the rotation angle sensor 150. The obtained traveling speed of the vehicle 100v is used when generating a traveling control signal (see step 103 in FIG. 6).

[0071] If the vehicle 100v has not finally reached the destination (step 217; NO), the process of step 211 is executed again. If the vehicle 100v has finally reached the destination (step 217; YES), the process of FIG. 7 is terminated.

[0072] As described above, in the present embodiment, when the traveling speed of the vehicle 100v is restricted, it is assumed that the vehicle 100v travels at a low speed. In this case, the reliability of the detection value of the vehicle speed sensor 140 is considered to be low. In this case, the speed of the vehicle is obtained using information regarding the rotational speed of the electric motor. When the traveling speed of the vehicle 100v at the current position is restricted, the speed of the vehicle is obtained using information regarding the rotational speed of the drive motor. Further, when the traveling speed of the vehicle 100v at the current position is not restricted, the traveling speed of the vehicle is not low. In this case, since the reliability of the detection value of the vehicle speed sensor 140 is high, the speed of the vehicle is obtained using the detection value of the vehicle speed sensor 140. For this reason, whether the vehicle is traveling at a low speed or not, the reliability of the detection of the speed of the vehicle can be ensured. Thus, which of the detection value of the vehicle speed sensor 140 or the information regarding the rotational speed of the drive motor is used to obtain the speed of the vehicle 100v is selected according to the situation regarding the speed of the vehicle 100v. For this reason, whether the vehicle is traveling at a low speed or not, the speed of the vehicle can be appropriately detected.

[0073] C. Other Embodiments: (C1) In the first embodiment, an example in which the condition for selecting the first method is that the target speed of the vehicle 100 is equal to or higher than a predetermined threshold value has been described. Further, in the second embodiment, an example in which the condition for selecting the first method is that there is no restriction on the traveling speed in the process where the vehicle 100 is located has been described. However, the condition for selecting the first method is not limited to these.

[0074] For example, in a configuration where the server 200 remotely controls the operation of the vehicle 100, when a failure occurs in another vehicle traveling around the vehicle 100, the server 200 may perform control to reduce the traveling speed of the vehicle 100 for a certain period of time from the occurrence of the failure. While being controlled to travel at a low speed in this way, the second method may be selected as a method for acquiring the speed of the vehicle 100. When a certain period of time has elapsed from the occurrence of the failure, for example, it is considered that the recovery work of the other vehicle in which the failure has occurred by the operator has been completed. Therefore, the server 200 controls the vehicle 100 to travel at the speed before changing to low speed again. In this case, the first method is selected as a method for acquiring the speed of the vehicle 100.

[0075] (C2) In the first embodiment, an example in which the condition for selecting the first method is that the target speed is equal to or higher than a predetermined threshold value has been described. However, even when the target speed is equal to or higher than a predetermined threshold value, for example, it is assumed that a certain period of time is required for the traveling speed of the vehicle 100 to reach the target speed after the vehicle 100 starts traveling. Therefore, the second method may be selected until a predetermined period of time has elapsed after the vehicle 100 starts traveling. After a predetermined period of time has elapsed after the vehicle 100 starts traveling, the second method may be selected.

[0076] (C3) In the first and second embodiments, when the second method is selected, the control value for controlling the autonomous driving of the vehicle 100 may include at least the target value of the vehicle speed. When the speed of the vehicle 100 is extremely low, the electric motor may be controlled to reach the target value of the speed, and it is not necessary to perform control taking into account the acceleration of the vehicle 100.

[0077] (C4) Also, in the first and second embodiments, when the first method is selected, the control value for controlling the autonomous driving of the vehicle 100 may include at least the target value of the acceleration of the vehicle 100.

[0078] Due to disturbances caused by the driving environment of the vehicle 100, accelerations in the longitudinal direction and lateral direction are applied to the vehicle. When the speed of the vehicle 100 is equal to or higher than a predetermined speed, changes in the accelerations in the longitudinal direction and lateral direction tend to increase. Therefore, due to the changes in the accelerations in the longitudinal direction and lateral direction, the driving of the vehicle 100 may become unstable. Thus, by controlling the acceleration of the vehicle 100, the driving of the vehicle 100 can be finely controlled.

[0079] (C5) In each of the above embodiments, the external sensor 300 is a camera. In contrast, the external sensor 300 may not be a camera, and for example, it may be a LiDAR (Light Detection And Ranging). In this case, the detection result output by the external sensor 300 may be three-dimensional point cloud data representing the vehicle 100. In this case, the server 200 or the vehicle 100 may acquire vehicle position information by template matching using the three-dimensional point cloud data as the detection result and reference point cloud data prepared in advance.

[0080] (C6) In the first embodiment above, the server 200 executes the process from the acquisition of vehicle position information to the generation of a driving control signal. In contrast, at least a part of the process from the acquisition of vehicle position information to the generation of a driving control signal may be executed by the vehicle 100. For example, it may be in the following forms (1) to (3).

[0081] (1) The server 200 may acquire vehicle position information, determine the target position to which the vehicle 100 should next head, and generate a route from the current position of the vehicle 100 represented by the acquired vehicle position information to the target position. The server 200 may generate a route to the target position between the current position and the destination, or may generate a route to the destination. The server 200 may transmit the generated route to the vehicle 100. The vehicle 100 may generate a driving control signal so that the vehicle 100 travels on the route received from the server 200, and control the actuator group 120 using the generated driving control signal.

[0082] (2) The server 200 may acquire vehicle position information and transmit the acquired vehicle position information to the vehicle 100. The vehicle 100 may determine the target position to which the vehicle 100 should next head, generate a route from the current position of the vehicle 100 represented in the received vehicle position information to the target position, generate a driving control signal so that the vehicle 100 travels on the generated route, and control the actuator group 120 using the generated driving control signal.

[0083] (3) In the forms (1) and (2) above, an internal sensor is mounted on the vehicle 100, and the detection result output from the internal sensor may be used for at least one of the generation of the route and the generation of the driving control signal. The internal sensor is a sensor mounted on the vehicle 100. The internal sensor may include, for example, a sensor that detects the motion state of the vehicle 100, a sensor that detects the operating state of each part of the vehicle 100, or a sensor that detects the environment around the vehicle 100. Specifically, the internal sensor may include, for example, a camera, LiDAR, millimeter-wave radar, ultrasonic sensor, GPS sensor, acceleration sensor, gyro sensor, etc. For example, in the form (1) above, the server 200 may acquire the detection result of the internal sensor and reflect the detection result of the internal sensor in the route when generating the route. In the form (1) above, the vehicle 100 may acquire the detection result of the internal sensor and reflect the detection result of the internal sensor in the driving control signal when generating the driving control signal. In the form (2) above, the vehicle 100 may acquire the detection result of the internal sensor and reflect the detection result of the internal sensor in the route when generating the route. In the form (2) above, the vehicle 100 may acquire the detection result of the internal sensor and reflect the detection result of the internal sensor in the driving control signal when generating the driving control signal.

[0084] (C7) In the second embodiment described above, the vehicle 100v is equipped with an internal sensor, and the detection result output from the internal sensor may be used for at least one of the generation of the route and the generation of the driving control signal. For example, the vehicle 100v may acquire the detection result of the internal sensor and reflect the detection result of the internal sensor in the route when generating the route. The vehicle 100v may acquire the detection result of the internal sensor and reflect the detection result of the internal sensor in the driving control signal when generating the driving control signal.

[0085] (C8) In the second embodiment, the vehicle 100v acquires vehicle position information using the detection result of the external sensor 300. In contrast, the vehicle 100v is equipped with an internal sensor, and the vehicle 100v acquires vehicle position information using the detection result of the internal sensor, determines the target position that the vehicle 100v should head to next, generates a route from the current position of the vehicle 100v represented in the acquired vehicle position information to the target position, generates a driving control signal for driving on the generated route, and may control the actuator group 120 using the generated driving control signal. In this case, the vehicle 100v can travel without using the detection result of the external sensor 300 at all. Note that the vehicle 100v may acquire the target arrival time and traffic jam information from outside the vehicle 100v and reflect the target arrival time and traffic jam information in at least one of the route and the driving control signal. Also, all the functional configurations of the system 50v may be provided in the vehicle 100v. That is, the processing realized by the system 50v in the present disclosure may be realized by the vehicle 100v alone.

[0086] (C9) The vehicle 100 may be manufactured by combining a plurality of modules. A module means a unit composed of a plurality of parts grouped according to the parts and functions of the vehicle 100. For example, the platform of the vehicle 100 may be manufactured by combining a front module that constitutes the front part of the platform, a center module that constitutes the central part of the platform, and a rear module that constitutes the rear part of the platform. Note that the number of modules constituting the platform is not limited to three, and may be two or less or four or more. Further, in addition to the parts constituting the platform, or instead of these, the parts constituting a portion of the vehicle 100 different from the platform may be modularized. Further, each type of module may include any exterior parts such as "running" or a grille, and any interior parts such as a seat or a console. Further, not limited to the vehicle 100, any type of moving body may be manufactured by combining a plurality of modules. Such modules may be manufactured, for example, by joining a plurality of parts by welding, fixtures, or the like, or by integrally molding at least a part of the parts constituting the module by casting as one part. The molding method of integrally molding one part, particularly a relatively large part, is also called gigacasting or megacasting. For example, the above-mentioned front module, center module, and rear module may be manufactured using gigacasting.

[0087] (C10) Using the running of the vehicle 100 by autonomous driving to transport the vehicle 100 is also called "self-propelled transport". Further, the configuration for realizing self-propelled transport is also called "vehicle remote control autonomous driving transport system". Further, the production method of producing the vehicle 100 using self-propelled transport is also called "self-propelled production". In self-propelled production, for example, in the factory FC that manufactures the vehicle 100, at least a part of the transport of the vehicle 100 is realized by self-propelled transport.

[0088] (C11) In each of the above embodiments, some or all of the functions and processes implemented software may be implemented hardware. Conversely, some or all of the functions and processes implemented hardware may be implemented software. As the hardware for implementing the various functions in each of the above embodiments, for example, various circuits such as integrated circuits and discrete circuits may be used.

[0089] The present disclosure is not limited to the above-described embodiments, and can be implemented in various configurations without departing from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be appropriately replaced or combined in order to solve the above-described problems or to achieve some or all of the above-described effects. Further, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

Explanation of Reference Numerals

[0090] 50, 50v... system, 100, 100v... vehicle, 110, 110v... vehicle control device, 111, 111v... processor, 112, 112v... memory, 113... input / output interface, 114... internal bus, 115, 115v... vehicle control unit, 116... speed calculation unit, 117... motor rotation speed calculation unit, 120... actuator group, 123... position estimation unit, 128... selection unit, 129... speed acquisition unit, 130... communication device, 140... vehicle speed sensor, 150... rotation angle sensor, 200... server, 201... processor, 202... memory, 203... input / output interface, 204... internal bus, 205... communication device, 210... selection unit, 230... speed acquisition unit, 240... position estimation unit, 250... remote control unit, 300... external sensor, DM... detection model, FC... factory, GC... global coordinate system, PG1... program, PG1v... program, PG2... program, PL1... first location, PL2... second location, PL3... third location, RR... reference path, TR... runway

Claims

1. A monitoring device for monitoring a vehicle that travels by autonomous driving using an electric motor as a power source, a first method of obtaining the speed of the vehicle using a detection value of a vehicle speed sensor that outputs in synchronization with the rotation of the wheels of the vehicle, and a second method of obtaining the speed of the vehicle using information regarding the rotational speed of the electric motor provided in the vehicle, a selection unit that selects which method to use to obtain the speed of the vehicle according to the situation regarding the speed of the vehicle, a speed acquisition unit that acquires the speed of the vehicle by the method selected by the selection unit, comprising a monitoring device.

2. The monitoring device according to claim 1, wherein the selection unit selects the first method when a predetermined condition indicating that the detection value of the vehicle speed sensor is highly reliable is satisfied, and selects the second method when the condition is not satisfied, a monitoring device.

3. The monitoring device according to claim 2, wherein the condition includes that the detection value of the vehicle speed sensor is equal to or higher than a predetermined speed, a monitoring device.

4. The monitoring device according to claim 2, wherein the vehicle is a vehicle that travels within a factory where a plurality of processes are performed to manufacture the vehicle, and the condition includes that there is no limit on the traveling speed of the vehicle in the current process of the vehicle, a monitoring device.

5. The monitoring device according to claim 3, wherein when the first method is selected, the control value for controlling the autonomous driving of the vehicle includes at least a target value of the acceleration of the vehicle, a monitoring device.

6. A monitoring device according to any one of claims 3 to 5, when the second method is selected, the control value for controlling the driverless operation of the vehicle includes at least a target value of the speed of the vehicle, Monitoring device.

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