Driving control device and program

Abstract

To further improve the safety of vehicles when traveling on inclined road surfaces. [Solution] The driving control device according to the embodiment includes a controller. The controller controls the driving of a vehicle that is moving by driving the wheels with a driving motor. The controller also detects the inclination angle of the road surface where the vehicle is located, and stops the vehicle if the detected inclination angle is greater than or equal to a threshold.

Description

Technical Field

[0001] The disclosed embodiments relate to a driving control device and a program.

Background Art

[0002] Conventionally, although vehicles such as electric wheelchairs travel at a relatively low speed, for example, when going downhill while moving forward, if the inclination angle of the road surface increases, the user's posture may become unstable.

[0003] Therefore, for example, a technique has been proposed to reduce the instability of the user's posture by controlling the upper limit of the driving vehicle speed to decrease as the inclination angle of the road surface increases, thereby improving safety (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above-described conventional technology, even when the inclination angle of the road surface increases, at least a non-zero value is set as the upper limit of the driving vehicle speed, allowing the vehicle to travel. Therefore, there is room for further improvement in the above-described conventional technology to further improve the safety when the vehicle travels on an inclined road surface.

[0006] One aspect of the embodiment is made in view of the above, and an object is to provide a driving control device and a program that can further improve the safety when a vehicle travels on an inclined road surface.

Means for Solving the Problems

[0007] A driving control device according to one embodiment includes a controller. The controller controls the driving of a vehicle that is driven by a driving motor that drives the wheels. The controller also detects the inclination angle of the road surface where the vehicle is located, and stops the vehicle if the detected inclination angle is greater than or equal to a threshold. [Effects of the Invention]

[0008] According to one embodiment, the controller of the driving control device stops the vehicle if the inclination angle of the vehicle on the road surface exceeds a threshold, thus preventing the vehicle from being able to travel on a steeply inclined road surface, even at a low speed. In other words, according to one embodiment, the safety of the vehicle when traveling on an inclined road surface can be further improved. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a diagram showing the schematic configuration of a vehicle according to this embodiment. [Figure 2] Figure 2 is a schematic diagram illustrating the driving control method according to the embodiment. [Figure 3] Figure 3 shows an example of the configuration of a driving control device according to an embodiment. [Figure 4] Figure 4 shows an example of tilt angle control information. [Figure 5] Figure 5 is a flowchart showing the processing procedure for the driving control process performed by the driving control device according to the embodiment, based on the road surface inclination angle. [Figure 6] Figure 6 shows an example of guidance recommending manual mode or failsafe mode. [Figure 7] Figure 7 shows an example of guidance explaining the manual push mode. [Figure 8] Figure 8 shows an example of guidance explaining failsafe mode. [Figure 9] Figure 9 is a flowchart showing the processing procedure for the manual push mode. [Figure 10]Figure 10 shows an example of guidance when the vehicle becomes capable of normal operation while in push mode. [Figure 11] Figure 11 is a flowchart showing the processing procedure for failsafe mode. [Figure 12] Figure 12 shows an example of guidance when normal driving becomes possible after being in failsafe mode. [Figure 13] Figure 13 is a timing chart for transitioning to manual mode. [Figure 14] Figure 14 is a timing chart for transitioning to failsafe mode. [Modes for carrying out the invention]

[0010] The embodiments of the driving control device and program disclosed herein will be described in detail below with reference to the attached drawings. However, the present invention is not limited to the embodiments described below.

[0011] Furthermore, in the following description, the vehicle V according to the embodiment is assumed to be a small vehicle such as an electric wheelchair, electric cart, or mobility scooter. Vehicle V is an electric vehicle that moves by driving its wheels with a drive motor.

[0012] Vehicle V, for example, has a legally limited maximum speed (e.g., 6 km / h) and is capable of traveling on sidewalks. In the embodiments of this disclosure (hereinafter referred to as "this embodiment" as appropriate), it is particularly effective for vehicle V to have three or more wheels (e.g., four wheels) and to have stability when stationary (less likely to tip over). In the case of vehicles with two wheels or the like, which have low stability when stationary, stopping the vehicle does not significantly improve stability, but in the case of vehicles with three or more wheels, stopping the vehicle can significantly improve stability. Note that vehicle V is not limited to the small electric vehicle described above or the low-speed vehicle capable of traveling on sidewalks described above. Vehicle V may be, for example, a passenger car or truck that travels on roadways.

[0013] FIG. 1 is a diagram showing a schematic configuration of a vehicle V according to an embodiment. Further, FIG. 2 is a schematic explanatory diagram of a driving control method according to the embodiment. The driving control method according to the embodiment is executed by a controller 12 (see FIG. 3) included in a driving control device 10 mounted on the vehicle V.

[0014] As shown in FIG. 1, the vehicle V includes a driving control device 10, a motor 22, and an electromagnetic brake 23. The motor 22 corresponds to an example of a "driving motor". Further, the vehicle V includes a manual brake 5, an inclination sensor 6, and an HMI (Human Machine Interface) unit 7.

[0015] The vehicle V travels by driving the wheels with the motor 22. The driving control device 10 performs driving control of such a vehicle V. The driving control device 10 is a computer such as a VCU (Vehicle Control Unit) for example.

[0016] A plurality of motors 22 are provided. The motors 22 are provided on the left and right rear wheels respectively for example. The motor 22 is an in-wheel motor. The motor 22 generates a driving force for driving the rear wheels when a driving current is supplied from a battery (not shown). The controller 12 of the driving control device 10 controls the supply of the driving current to such a motor 22.

[0017] The electromagnetic brake 23 is provided in the vicinity of the motor 22. The electromagnetic brake 23 mechanically locks the motor 22 so as not to rotate by being electrically turned on. The electromagnetic brake 23 is provided as a lock mechanism that inserts and removes a lock pin by a solenoid actuator for example. Hereinafter, turning on electrically may be referred to as "turning on". Similarly, turning off may be referred to as "turning off".

[0018] Alternatively, the electromagnetic brake 23 may be configured to mechanically lock the motor 22 so that it cannot rotate when electrically switched off, the opposite of the configuration described above. Below, we will mainly describe an example in which the motor 22 is locked by turning on the electromagnetic brake 23.

[0019] On the other hand, the brake lever for operating the manual brake 5 is provided, for example, near the handle of the vehicle V. The manual brake 5 is a mechanism that brakes the wheels of the vehicle V in accordance with the force applied by the user riding in the vehicle V. The manual brake 5 is a friction brake that brakes the wheels by frictional force corresponding to the force applied when the user grips the brake lever, for example, and is provided separately from the electromagnetic brake 23.

[0020] The tilt sensor 6 is a sensor that detects the tilt of the vehicle body V. The tilt sensor 6 is installed, for example, near the rear axle of the vehicle V, and detects the tilt of the vehicle body V in the longitudinal direction. The tilt sensor 6 may also be installed, for example, within the driving control unit 10 (VCU).

[0021] The HMI unit 7 is a user interface responsible for inputting and outputting information related to the vehicle V's operation. The HMI unit 7 is implemented by an input / output device equipped with a display device, such as a touch panel display. The HMI unit 7 may also include hardware switches, microphones, etc., as input interfaces. Furthermore, the HMI unit 7 may also include speakers, etc., as output interfaces.

[0022] In such a vehicle V, the controller 12 of the driving control device 10 detects the longitudinal tilt of the vehicle V detected by the tilt sensor 6 as the road surface tilt angle, as shown in Figure 2. Then, depending on this tilt angle, the controller 12 performs driving control to ensure safety, by basically reducing the upper limit speed of the vehicle V as the tilt angle increases. Hereinafter, this basic driving control in response to the road surface tilt angle may be referred to as "normal driving control".

[0023] However, if, for example, the road surface inclination angle exceeds the vehicle V's guaranteed range, it is preferable to stop the vehicle V and use inclination-specific driving control to move the vehicle V to a position where the road surface is at least at a safe inclination angle, rather than continuing to drive the vehicle V with normal driving control.

[0024] Therefore, in the driving control method according to this embodiment, the controller 12 stops the vehicle V when the road surface inclination angle is greater than or equal to a threshold. Specifically, as shown in Figure 2, the controller 12 detects the inclination angle of the road surface where the vehicle V is located, and if the inclination angle is greater than or equal to a threshold, it stops the vehicle V and turns on the electromagnetic brake 23 (step S1).

[0025] In step S1, the controller 12 stops the vehicle V by setting the aforementioned upper speed limit to zero. This ensures safety, for example, on road surfaces with an incline exceeding the guaranteed range. In addition, by turning on the electromagnetic brake 23, the vehicle V can be stopped reliably, further improving safety.

[0026] Then, if the controller 12 detects the immobile state after step S1 (i.e., the vehicle speed is zero and the electromagnetic brake 23 is on), it enters a standby state in which it can switch the vehicle V to push mode or fail-safe mode (step S2). In this standby state, if the user performs an operation to switch the vehicle V to push mode or fail-safe mode, the controller 12 switches the vehicle V to the respective mode corresponding to the user's operation.

[0027] As described above, vehicle V has a push mode and a fail-safe mode. The push mode is a mode in which the user can move vehicle V by pushing it. This makes it possible for the user to push vehicle V by hand to move it away from, for example, a steep slope. In a narrow sense, the push mode refers to the driving mode that is entered when the push button 4 (see Figure 3) is pressed by the user. However, in this embodiment, the push mode refers to the control state that is entered when the user chooses to use the push mode in a narrow sense to escape when the vehicle has stopped on an inclined road surface.

[0028] On the other hand, the fail-safe mode is a mode in which the user can move the vehicle V using the manual brake 5. Specifically, in fail-safe mode, the controller 12 sets the motor 22 to an unloaded state with an upper limit on its rotational speed, and the user can move the vehicle V by releasing the manual brake 5. This makes it possible for the user to move the vehicle V away from, for example, a steeply sloping road surface using only the manual brake 5.

[0029] In the standby state of step S2, if the user performs an operation to switch vehicle V to push mode, the controller 12 starts push driving control. Also, if the user performs an operation to switch vehicle V to failsafe mode, the controller 12 starts manual brake driving control. Specific examples of each of these driving controls will be described later using Figure 4 and subsequent figures.

[0030] Then, if the vehicle V can move to a road surface with a safe incline angle using the push mode or failsafe mode, the vehicle V returns from the push mode or failsafe mode (these modes will no longer be selected by the user). The controller 12 then drives the vehicle V using normal driving control.

[0031] As described above, in the driving control method according to this embodiment, the controller 12 of the driving control device 10 detects the inclination angle of the road surface on which the vehicle V is located, and stops the vehicle V if the detected inclination angle is greater than or equal to a threshold. As a result, the controller 12 stops the vehicle V if the inclination angle of the road surface on which the vehicle V is located exceeds a threshold, thus preventing the situation in which the vehicle V may be able to travel on a steeply inclined road surface, even at a low speed. In other words, the driving control method according to this embodiment can further improve the safety of the vehicle when it is traveling on an inclined road surface.

[0032] The configuration example of the driving control device 10 according to the embodiment will be described in more detail below. Figure 3 is a diagram showing the configuration example of the driving control device 10 according to the embodiment. As shown in Figure 3, the driving control device 10 comprises a storage unit 11 and a controller 12.

[0033] The storage unit 11 is implemented by a storage device such as ROM (Read Only Memory), RAM (Random Access Memory), flash memory, or disk drive. In the example shown in Figure 3, the storage unit 11 stores tilt angle control information 11a.

[0034] The inclination angle control information 11a is information that the controller 12, described later, refers to when performing driving control according to the inclination angle of the road surface. Figure 4 shows an example of the inclination angle control information 11a. As shown in Figure 4, the inclination angle control information 11a is map information that defines the upper limit speed according to the inclination angle of the road surface.

[0035] Based on the inclination angle control information 11a, the controller 12 controls the vehicle V to reduce its upper speed limit as the inclination angle of the road surface increases. Furthermore, if the inclination angle exceeds a threshold, the controller 12 controls the vehicle V to stop by setting the upper speed limit to zero.

[0036] The tilt angle control information 11a is defined, for example, as two-dimensional map information consisting of a Cartesian coordinate system with the tilt angle on the horizontal axis and the vehicle speed on the vertical axis. Figure 4 shows an example of tilt angle control information 11a in which, for example, the vehicle speed when moving forward is represented as a positive value and the vehicle speed when moving backward is represented as a negative value (actual vehicle speed is an absolute value), and the first quadrant where both the tilt angle and vehicle speed are positive values ​​is associated with the "forward downhill" state when the vehicle V moves forward down a slope.

[0037] Therefore, in the example in Figure 4, the second quadrant, where the incline angle is negative and the vehicle speed is positive, corresponds to "forward uphill," where vehicle V is moving forward while going uphill. The third quadrant, where both the incline angle and vehicle speed are negative, corresponds to "reverse downhill," where vehicle V is moving backward while going downhill. The fourth quadrant, where the incline angle is positive and the vehicle speed is negative, corresponds to "reverse uphill," where vehicle V is moving backward while going uphill.

[0038] In the example in Figure 4, the relative magnitudes of the inclination angles are |a°|<|b°|<|c°|. Also, the maximum upper limit speed when moving forward is the legal speed limit of 6 km / h. In this case, when moving forward downhill, the controller 12 starts to reduce the upper limit speed from 6 km / h at an absolute value of the inclination angle |a°| (first threshold), and continues to reduce the upper limit speed as the absolute value of the inclination angle increases. The changed upper limit speed is at least greater than zero. Then, the controller 12 sets the upper limit speed to zero at an absolute value of the inclination angle |c°| (second threshold).

[0039] Furthermore, in the example in Figure 4, the absolute value of the maximum speed limit when reversing is lower than the absolute value of the maximum speed limit when moving forward. This is to ensure safety when the vehicle V is reversing. Also, in the example in Figure 4, the absolute value of the inclination angle at which the maximum speed limit begins to decrease when reversing is greater than the absolute value of the inclination angle |a°| at which the maximum speed limit begins to decrease when moving forward is greater than the absolute value of the inclination angle |b°|. This is to consider situations such as parking while reversing on an inclined surface. Therefore, in the example in Figure 4, when reversing downhill, the controller 12 further reduces the maximum speed limit even if the inclination angle is greater than the absolute value of |b°|, but does not reduce the maximum speed limit to zero. This is to prevent the vehicle V from coming to a complete stop even if parking is in progress. Note that although the maximum speed limit is not reduced to zero when reversing downhill, it may be reduced to zero, as in the case of moving forward downhill.

[0040] Furthermore, in the example shown in Figure 4, the controller 12 drives the vehicle V while maintaining the upper speed limit so that the vehicle V can reliably climb against the slope when moving forward or backward.

[0041] Returning to the explanation of Figure 3, the controller 12 corresponds to a so-called processor. The controller 12 is implemented by a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), etc. The controller 12 executes a program according to an embodiment not shown, stored in the memory unit 11, using RAM as the working area. The controller 12 can also be implemented by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0042] The controller 12 is connected to the battery 2, the accelerator 3, the push button 4, the manual brake 5, the tilt sensor 6, and the HMI unit 7. Additionally, the controller 12 is connected to a motor controller 21 corresponding to each drive wheel, and an electromagnetic brake 23.

[0043] A motor 22 is connected to each of the motor controllers 21. In this embodiment, for example, a motor controller 21-1, a motor 22-1, and an electromagnetic brake 23-1 are provided on the left rear wheel side of the vehicle V. Also, for example, a motor controller 21-2, a motor 22-2, and an electromagnetic brake 23-2 are provided on the right rear wheel side of the vehicle V.

[0044] These various devices connected to the controller 12 are connected to the controller 12 via an in-vehicle network such as CAN (Controller Area Network) or via direct wires.

[0045] Battery 2 supplies power to the driving control device 10 as well as various devices connected to the controller 12. The accelerator 3 is operated by the user, and the amount of that operation is output to the controller 12.

[0046] The push button 4 is a button switch that the user presses to switch to manual mode. The push button 4 may be located, for example, near the seat of the vehicle V. While the user continues to press the push button 4, or for a certain period of time after pressing it, or until the release operation is performed after pressing it, the controller 12 switches the vehicle V to manual mode, turns off the electromagnetic brake 23, and causes the motor controller 21 to put the motor 22 into an unloaded state (free rotation state).

[0047] The manual brake 5, tilt sensor 6, HMI unit 7, motor 22, and electromagnetic brake 23 have already been explained, so their explanation will be omitted here. The motor controller 21 controls the drive of the motor 22 based on instruction signals such as rotational speed from the controller 12. The motor controller 21 is, for example, an inverter and a control circuit that controls the inverter.

[0048] The controller 12 generates an instruction signal for the rotational speed of the motor 22 in response to the operation of the accelerator 3, and outputs the generated instruction signal to the motor controller 21. The controller 12 also generates an instruction signal to turn the electromagnetic brake 23 on or off, and outputs the generated instruction signal to the electromagnetic brake 23.

[0049] Furthermore, the controller 12 executes a driving control process according to the processing procedure shown in Figure 5, based on the road surface inclination angle detected by the inclination sensor 6. Next, this processing procedure will be explained.

[0050] Furthermore, when the controller 12 transitions to the standby state of step S2 described above during this processing procedure, it notifies the user via the HMI unit 7 that it recommends either manual mode or failsafe mode. In response to this notification, the controller 12 performs the respective driving controls for manual mode or failsafe mode according to the operation selected by the user. Hereafter, notifications made via the HMI unit 7 may be referred to as "guidance." Specific examples of guidance regarding manual mode or failsafe mode will be described later using Figures 6 to 8, 10 and 12.

[0051] Figure 5 is a flowchart illustrating the processing procedure for the driving control process performed by the driving control device 10 according to the embodiment, based on the road surface inclination angle. Figure 5 shows the processing procedure for the "forward downhill" case described above.

[0052] Although not shown in the illustration, the processing procedure shown in Figure 5 is initiated when the vehicle V is powered on, etc. In other words, the controller 12 executes the processing procedure shown in Figure 5 while the vehicle V is starting up.

[0053] First, the controller 12 detects the inclination angle of the road surface based on the sensor signal from the inclination sensor 6 (step S101). Then, the controller 12 determines whether or not the inclination angle is below a threshold (step S102).

[0054] If the inclination angle is less than a threshold (step S102, Yes), the controller 12 changes the upper limit speed according to the inclination angle (step S103) and performs normal driving control to drive the vehicle V according to the upper limit speed and the operation of the accelerator 3 (step S104).

[0055] The controller 12 then determines whether the power has been turned off, that is, whether the system of vehicle V has been turned off (step S105). If the power is not off (step S105, No), the controller 12 repeats the process from step S101. If the power is off (step S105, Yes), the controller 12 terminates the process.

[0056] Furthermore, if the inclination angle is greater than or equal to a threshold (step S102, No), the controller 12 stops the vehicle V from moving by setting the upper speed limit to zero (step S106). Then, the controller 12 turns on the electromagnetic brake 23 (step S107).

[0057] Then, the controller 12 guides the user through the HMI unit 7 to either manual mode or failsafe mode (step S108). Specific examples of step S108 are shown in Figures 6 to 8.

[0058] Figure 6 shows an example of guidance recommending manual mode or failsafe mode. Figure 7 shows an example of guidance explaining manual mode. Figure 8 shows an example of guidance explaining failsafe mode.

[0059] When the incline angle is above a threshold, the vehicle V is stopped, and the electromagnetic brake 23 is on, the controller 12 displays a message to the HMI unit 7, for example, as shown in Figure 6. Specifically, the controller 12 displays a message such as, "Please move the vehicle until it reaches a safe incline using either push mode or failsafe mode," allowing the user to select one of the two modes. This allows the controller 12 to guide the user on how to deal with the situation when the vehicle V stops on a steep incline, thereby contributing to improving the marketability of the vehicle V.

[0060] If the user selects, for example, the manual push mode, the controller 12 will guide the user on how to operate in manual push mode, as shown in Figure 7. Similarly, if the user selects the failsafe mode, the controller 12 will guide the user on how to operate in failsafe mode, as shown in Figure 8.

[0061] Returning to the explanation of Figure 5, the controller 12 determines the user's selected mode according to the guidance in step S108 (step S109). If the user selects the manual mode (step S109, manual mode), the controller 12 executes the manual mode processing (step S110). If the user selects the failsafe mode (step S109, failsafe mode), the controller 12 executes the failsafe mode processing (step S111).

[0062] The processing procedures for manual mode processing and failsafe mode processing will be explained in order. Figure 9 is a flowchart of the processing procedure for manual mode processing. As shown in Figure 9, in manual mode processing, the controller 12 first determines whether the user has turned on the manual button 4 in accordance with the guidance shown in Figure 7, for example (step S201).

[0063] If push button 4 is off (step S201, No), controller 12 repeats step S201. If push button 4 is turned on (step S201, Yes), controller 12 turns off the electromagnetic brake 23 (step S202) and releases the wheel lock.

[0064] Then, the controller 12 starts manual push-driving control (step S203). In manual push-driving control, the controller 12 puts the motor 22 into an unloaded state and instructs the motor controller 21 to control the motor 22 so that its rotational speed does not rise above a predetermined value. This makes it possible for the user to push the vehicle V by hand and move it slowly and safely.

[0065] Then, the controller 12 detects the inclination angle during manual push-running control (step S204) and determines whether the inclination angle is below a threshold (step S205).

[0066] If the tilt angle falls below a threshold as the vehicle V moves (step S205, Yes), the controller 12 guides the user that normal driving is possible (step S206). A specific example is shown in Figure 10. Figure 10 shows an example of guidance when normal driving becomes possible in push mode.

[0067] In this case, as shown in Figure 10, the controller 12 displays to the HMI unit 7, for example, that the road surface has become a safe slope and that normal driving is possible if the user releases the push button 4. This allows the user to easily understand when normal driving is possible while in push mode, and also contributes to improving the marketability of the vehicle V.

[0068] Returning to the explanation of Figure 9, the controller 12 then determines whether the user has released their hand from the push button 4 and turned it off in response to step S206 (step S207). If the user has not released their hand (step S207, No), the controller 12 repeats step S207. If the user has released their hand (step S207, Yes), the controller 12 terminates the push-pull operation control (step S208), turns on the electromagnetic brake 23 (step S209), and terminates the push-pull mode processing.

[0069] Furthermore, if the inclination angle during manual push-run control is greater than or equal to a threshold (step S205, No), the controller 12 determines whether the user has released their hand from the push button 4 and turned it off, even though the inclination is still steep (step S210).

[0070] If the user does not release their hands (step S210, No), the controller 12 repeats the process from step S204. If the user releases their hands (step S210, Yes), the controller 12 temporarily terminates the manual push-driving control for safety reasons (step S211), turns on the electromagnetic brake 23 (step S212), and repeats the process from step S201.

[0071] Next, the fail-safe mode processing will be explained. Figure 11 is a flowchart showing the processing procedure for the fail-safe mode processing. As shown in Figure 11, in the fail-safe mode processing, the controller 12 first determines whether the user has turned on the manual brake 5 in accordance with the guidance shown in Figure 8, for example (step S301). Note that "turning on the manual brake 5" is a convenient expression for explanation purposes and refers to a state in which the user has applied the manual brake 5 so strongly that the rotation of the vehicle V's wheels stops. In other words, it refers to a state in which the vehicle speed is zero.

[0072] If manual brake 5 is not on (step S301, No), controller 12 repeats step S301. If manual brake 5 is on (step S301, Yes), controller 12 turns off electromagnetic brake 23 (step S302) and releases the wheel lock.

[0073] Then, the controller 12 starts manual brake driving control (step S303). In manual brake driving control, the controller 12 puts the motor 22 into an unloaded state and instructs the motor controller 21 to control the motor 22 so that its rotational speed does not rise above a predetermined value. At the same time, the controller 12 also turns off the accelerator control. This makes it possible for the user to move the vehicle V slowly and safely by releasing the manual brake 5.

[0074] Then, the controller 12 detects the tilt angle during manual brake driving control (step S304) and determines whether the tilt angle is less than a threshold (step S305).

[0075] If the tilt angle is greater than or equal to the threshold (step S305, No), the controller 12 repeats the process from step S304. Also, if the tilt angle falls below the threshold due to the movement of vehicle V (step S305, Yes), the controller 12 guides the user that normal driving is possible (step S306). A specific example is shown in Figure 12. Figure 12 is a diagram showing an example of guidance when normal driving becomes possible in failsafe mode.

[0076] In this case, as shown in Figure 12, the controller 12 displays to the HMI unit 7, for example, that normal driving is possible once the road surface has reached a safe slope and the vehicle has come to a stop using the manual brake 5. This allows the user to easily understand when normal driving becomes possible during failsafe mode, and also contributes to improving the marketability of the vehicle V.

[0077] Returning to the explanation of Figure 11, the controller 12 then determines whether the user has turned on the manual brake 5 in response to step S306, that is, whether the vehicle V has been stopped (step S307). If the vehicle V has not been stopped (step S307, No), the controller 12 repeats step S307. If the vehicle V has been stopped (step S307, Yes), the controller 12 terminates the manual brake driving control (step S308), turns on the electromagnetic brake 23 (step S309), and terminates the fail-safe mode processing.

[0078] Returning to the explanation of Figure 5, after the completion of the push mode processing or failsafe mode processing, when the controller 12 detects an operation by the user to transition to the normal driving control state, for example, when the accelerator 3 is operated from a state where it is not being operated, or when the brake lever is released from an operated state (step S112), it turns off the electromagnetic brake 23 (step S113).

[0079] The controller 12 then determines whether the power has been turned off or not (step S105). If the power is not off (step S105, No), the controller 12 repeats the process from step S101. If the power is off (step S105, Yes), the controller 12 terminates the process.

[0080] Figure 5 shows the processing procedure for the "forward downhill" case described above, but the processing procedures for "forward uphill," "reverse downhill," and "reverse uphill" will also be explained. In the case of "forward uphill," the controller 12 acquires the inclination angle, but in accordance with the map information of the second quadrant of the inclination angle control information 11a shown in Figure 4, it does not change the upper limit speed even if the inclination angle changes, and performs normal driving control while maintaining the upper limit speed at, for example, 6 km / h. Similarly, in the case of "reverse uphill," the controller 12 performs normal driving control while maintaining the upper limit speed without changing it even if the inclination angle changes, in accordance with the map information of the fourth quadrant of Figure 4.

[0081] In the case of "reverse downhill," the controller 12 acquires the inclination angle and, according to the map information in the third quadrant of Figure 4, maintains the upper limit speed without changing it until the inclination angle is less than the absolute value |b°|, while performing normal driving control. On the other hand, if the absolute value of the inclination angle is |b°| or greater, the controller 12 begins to reduce the upper limit speed at the absolute value of |b°|, and reduces the upper limit speed further as the inclination angle increases. At this time, the controller 12 may perform control to make the changed upper limit speed a value greater than zero at a minimum, or it may perform control to make it zero at a minimum. If control is performed to make it zero, the controller 12 will execute steps S106 to S113 in Figure 5, as in the case of "forward downhill."

[0082] Next, we will explain the timing charts for transitioning to manual mode and failsafe mode, as explained using Figures 5 to 12. Figure 13 is the timing chart for transitioning to manual mode. Figure 14 is the timing chart for transitioning to failsafe mode.

[0083] Let's start by explaining the timing chart for transitioning to manual mode. As shown in Figure 13, during normal driving control, where the upper limit speed is changed according to the inclination angle, let's assume that at time T1 the inclination angle exceeds the threshold. In that case, the controller 12 sets the upper limit speed to zero at time T1 to stop the vehicle V and turns on the electromagnetic brake 23.

[0084] Furthermore, the controller 12 also provides guidance to the user regarding whether to use manual mode or failsafe mode (see Figure 6). Let's assume the user selects manual mode.

[0085] In this case, when the user turns on the push button 4 at time T2, the controller 12 turns on the push-pull control, i.e., starts the push-pull control at time T2. During the push-pull control, the controller 12 controls the motor 22 to be in an unloaded state and sets an upper limit on the rotation speed of the motor 22.

[0086] Then, during manual push-running control, as the vehicle V moves, if the inclination angle falls below a threshold at time T3, the controller 12 provides guidance to the user that normal running is possible (see Figure 10). In response, if the user releases the push button 4 between time T3 and time T4 to turn it off, the controller 12 turns on the electromagnetic brake 23 and locks the rotation of the motor 22.

[0087] Then, when the controller 12 detects an operation to transition to the normal driving control state at time T4, it turns off the electromagnetic brake 23 to release the push mode and returns to normal driving control, which performs normal driving control while changing the upper limit speed according to the inclination angle.

[0088] Next, when transitioning to fail-safe mode, as shown in Figure 14, if the inclination angle exceeds a threshold at time T11 during normal driving control, the controller 12 sets the upper speed limit to zero at time T11 to stop the vehicle V and turns on the electromagnetic brake 23.

[0089] Furthermore, the controller 12 also provides guidance to the user regarding whether to press the button manually or to use the failsafe mode (see Figure 6). Suppose the user selects the failsafe mode.

[0090] In this case, when the user turns on the manual brake 5 at time T12, the controller 12 turns on the manual brake driving control, i.e., starts the manual brake driving control at time T12. During manual brake driving control, the controller 12 controls the motor 22 to be in an unloaded state, with an upper limit on the rotational speed of the motor 22, and without accelerator control.

[0091] Then, during manual braking control, as the vehicle V moves, if the tilt angle falls below a threshold at time T13, the controller 12 provides guidance to the user that normal driving is possible (see Figure 12). In response, if the user turns on the manual brake 5 between time T13 and time T14, the controller 12 turns on the electromagnetic brake 23 and locks the rotation of the motor 22.

[0092] Then, when the controller 12 detects an operation to transition to the normal driving control state at time T14, it turns off the electromagnetic brake 23 to release the fail-safe mode and returns to normal driving control, which performs normal driving control while changing the upper limit speed according to the inclination angle.

[0093] As described above, the driving control device 10 according to the embodiment includes a controller 12. The controller 12 controls the driving of a vehicle V that moves by driving its wheels with a motor 22 (corresponding to an example of a "driving motor"). The controller 12 also detects the inclination angle of the road surface where the vehicle V is located, and stops the vehicle V if the detected inclination angle is greater than or equal to a threshold.

[0094] Therefore, according to the driving control device 10 of the embodiment, the controller 12 stops the vehicle V when the inclination angle of the road surface above the vehicle V exceeds a threshold, thus avoiding a situation where the vehicle V could travel on a steeply inclined road surface, even at a low speed. In other words, according to the driving control device 10 of the embodiment, safety when the vehicle travels on an inclined road surface can be further improved.

[0095] In the embodiments described above, for example, Figure 6 shows an example of guidance that allows selection from either the push mode or the failsafe mode. However, the vehicle V may be configured to have only one of the two modes: the push mode or the failsafe mode. In this case, Figure 6 will provide guidance only for the push mode or only for the failsafe mode that the vehicle V has.

[0096] Further effects and modifications can be readily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents. [Explanation of Symbols]

[0097] 2 batteries 3 Accelerator 4 Push button 5. Manual brake 6. Tilt sensor 7 HMI section 10. Driving control device 11 Storage section 11a Tilt angle control information 12 controllers 21 Motor Controller 22 motors 23 Electromagnetic brake V Vehicle

Claims

1. It is equipped with a controller that controls the movement of a vehicle that moves by driving its wheels with a drive motor, The aforementioned controller, The aforementioned vehicle detects the inclination angle of a road surface, If the detected tilt angle is greater than or equal to a threshold, the vehicle is stopped. Driving control device.

2. The aforementioned controller, If the aforementioned inclination angle is greater than or equal to the first threshold, the vehicle's upper limit speed is reduced to a modified upper limit speed which is greater than zero. If the inclination angle is greater than or equal to a second threshold which is greater than the first threshold, the vehicle is stopped by setting the upper speed limit to zero. The driving control device according to claim 1.

3. The aforementioned controller, When the inclination angle is less than the threshold, the vehicle's upper speed limit is reduced as the inclination angle increases. When the inclination angle exceeds the threshold, the vehicle is stopped by setting the upper speed limit to zero. The driving control device according to claim 1.

4. The vehicle is equipped with an electromagnetic brake that locks the drive motor so that it cannot rotate, The controller stops the vehicle and locks the drive motor with the electromagnetic brake when the tilt angle is greater than or equal to the threshold. The driving control device according to claim 1.

5. The vehicle has a push mode that allows the vehicle to be moved by the user pushing it. The driving control device according to claim 4.

6. The controller, when the tilt angle is greater than or equal to the threshold, the vehicle is stopped, and the drive motor is locked by the electromagnetic brake, notifies the user to switch to the manual push mode. The driving control device according to claim 5.

7. The vehicle is equipped with a manual brake that applies braking force to the wheels in accordance with the force applied by the user, and has a fail-safe mode that moves the vehicle using the manual brake. The driving control device according to claim 4.

8. The controller, when the tilt angle is greater than or equal to the threshold, the vehicle is stopped, and the drive motor is locked by the electromagnetic brake, notifies the user to switch to the fail-safe mode. The driving control device according to claim 7.

9. The aforementioned controller, If the inclination angle is greater than or equal to the threshold, the vehicle is stopped, and during the vehicle's retreat, if the inclination angle falls below the threshold, the user is notified that normal driving is now possible. The driving control device according to claim 6 or 8.

10. A program to be executed by a computer that controls the movement of a vehicle that moves by driving its wheels with a motor, The aforementioned vehicle detects the inclination angle of a road surface, If the detected tilt angle is greater than or equal to a threshold, the vehicle is stopped. program.

Images