JP6953166B2 - Automatic driving control device and automatic driving control method for electric vehicles - Google Patents

Description

The present invention relates to an automatic traveling control device and an automatic traveling control method for an electric vehicle, and more particularly to an apparatus and a method for controlling automatic approach traveling of an electric vehicle on a narrow road.

Conventionally, there has been provided a control technique in which an ultrasonic sensor is attached to the front of an electric wheelchair, an obstacle existing in the front is detected, and the obstacle is avoided by an automatic turning operation. An ultrasonic sensor is a sensor that detects the presence or absence of an obstacle and the distance to the obstacle based on the time it takes for the device to emit ultrasonic waves and receive the reflected wave from the obstacle.

The ultrasonic waves are emitted from the transducer in a beam shape with a certain spread. The shape of the beam is called the directivity of the ultrasonic sensor. The directivity of conventional ultrasonic sensors is not so sharp, and the half-value angle has a spread of about 20 to 30 degrees. Therefore, on a narrow road, even if there is a route wider than the width of the wheelchair, the wall of the route is detected as an obstacle and the route is detoured by the automatic turning operation. Therefore, there is a problem that it is not possible to enter a narrow road by automatic driving.

FIG. 15 is a diagram for explaining the above-mentioned conventional problem. FIG. 15 shows an example in which ultrasonic sensors are attached to three places in front of the electric wheelchair 100. One is installed in the center in the vehicle width direction, and two are installed near both ends in the vehicle width direction, both of which emit ultrasonic waves toward the front of the electric wheelchair 100. Further, in front of the electric wheelchair 100, there is a narrow road 200 having a path width slightly wider than the vehicle width of the electric wheelchair 100. In this case, since the directivity of the ultrasonic sensor is wide, the walls on both sides of the narrow path 200 are detected by the ultrasonic sensors at both ends. As a result, the wall of the narrow road 200 is recognized as one obstacle, and an automatic turning operation that bypasses the wall is performed, and as a result, the narrow road 200 cannot be entered.

In addition, even if it detects that there is an obstacle in the driving direction and stops driving, it is possible to drive the vehicle so that it is surely away from the obstacle without spending a lot of time and effort. Wheelchairs are known (see, for example, Patent Document 1). In the electric wheelchair described in Patent Document 1, when an obstacle is detected by an obstacle detection sensor during traveling, if the vehicle is instructed to travel in a direction other than the direction in which the detected obstacle exists, the obstacle is detected. Allows the vehicle to travel in a direction other than the direction in which the vehicle exists, and prohibits travel in that direction when instructed to travel in the direction in which the obstacle exists.

Japanese Unexamined Patent Publication No. 2003-334218

However, even if the technique described in Patent Document 1 is used, if a narrow road is detected as an obstacle, it is prohibited to proceed in the direction of the narrow road, so that it is not possible to enter the narrow road.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to enable automatic approach traveling even on a narrow road in automatic traveling control of an electric vehicle. do.

In order to solve the above-mentioned problems, in the present invention, distance sensors having a narrow directionality in which the spread angle of the transmitted signal is equal to or less than a predetermined value are installed near both ends in the vehicle width direction of the electric vehicle, and the respective distance sensors are installed. Sends a signal toward the front of the electric vehicle. Then, the turning motion of the electric vehicle to the left and right is controlled based on the left front distance and the right front distance to the obstacle detected by the distance sensors near both ends in the vehicle width direction.

According to the present invention configured as described above, the distance from the vicinity of the left end of the electric vehicle to the obstacle in the narrow region on the extension line to the front (the front distance on the left side) is determined by the left and right distance sensors having narrow directivity. , The distance from the vicinity of the right end of the electric vehicle to the obstacle in the narrow area on the extension line to the front (the front distance on the right side) is detected individually. Therefore, when the electric vehicle is traveling toward a narrow road, it is possible that the electric vehicle is traveling toward a narrow road instead of one obstacle due to the difference between the front distance on the left side and the front distance on the right side. It can be recognized that there is, and it becomes possible to automatically approach a narrow road by turning left and right.

It is a figure which shows the installation example of the distance sensor with respect to the electric wheelchair by 1st Embodiment. It is a block diagram which shows the functional structure example of the automatic driving control device by 1st Embodiment. It is a figure for demonstrating the condition for performing the turning operation to the left-right by the turning control part by 1st Embodiment. It is a figure for demonstrating the condition for stopping an electric wheelchair by the stop control unit by 1st Embodiment. It is a flowchart which shows the operation example of the automatic driving control apparatus by 1st Embodiment. It is a figure for demonstrating the problem in the case where an electric wheelchair is traveling at a position near a side wall on the right side in a narrow road. It is a figure which shows the other installation example of the distance sensor with respect to the electric wheelchair. It is a block diagram which shows the other functional configuration example of the automatic driving control apparatus by 1st Embodiment. It is a block diagram which shows the functional structure example of the automatic driving control device by 2nd Embodiment. It is a figure for demonstrating the operation example of the distance measurement error determination part and the turning control part by 2nd Embodiment. It is a flowchart which shows the operation example of the automatic driving control apparatus by 2nd Embodiment. It is a figure for demonstrating a problem when an electric wheelchair enters an acute angle with respect to a narrow road. It is a block diagram which shows the functional structure example of the automatic driving control device by 3rd Embodiment. It is a figure for demonstrating the operation example of the turning control part by 3rd Embodiment. It is a figure for demonstrating a conventional problem.

(First Embodiment)
Hereinafter, the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an installation example of a distance sensor for an electric wheelchair according to the first embodiment. As shown in FIG. 1, in the first embodiment, two first distance sensors 101L and 101R (corresponding to the distance sensors in the claims) are provided near both ends of the electric wheelchair 100 in the vehicle width direction. Signals are transmitted from the distance sensors 101L and 101R of No. 1 toward the front of the electric wheelchair 100, respectively.

The first distance sensors 101L and 101R are sensors having narrow directivity in which the spread angle of the transmitted signal is equal to or less than a predetermined value. For example, the laser range finder can be used as the first distance sensors 101L and 101R. The first distance sensor 101L installed near the left end of the electric wheelchair 100 detects the distance (front distance on the left side) from the vicinity of the left end of the electric wheelchair 100 to an obstacle in a narrow region on the extension line to the front. Further, the first distance sensor 101R installed near the right end of the electric wheelchair 100 detects the distance from the vicinity of the right end of the electric wheelchair 100 to an obstacle in a narrow region on the extension line forward (front distance on the right side). do.

Further, in the first embodiment, a second distance sensor 102C is further provided near the center of the electric wheelchair 100 in the vehicle width direction, and a signal is transmitted from the second distance sensor 102C toward the front of the electric wheelchair 100. ing. The second distance sensor 102C is for detecting an obstacle existing within the vehicle body width of the electric wheelchair 100, and for example, an ultrasonic sensor can be used.

FIG. 2 is a block diagram showing a functional configuration example of the automatic traveling control device according to the first embodiment mounted on the electric wheelchair 100. The automatic driving control device according to the first embodiment performs automatic driving control of the electric wheelchair 100, and has a functional configuration of the first distance detecting unit 11 (corresponding to the distance detecting unit within the claims). , A second distance detection unit 12, a turning control unit 13, a threshold value changing unit 14, a stop control unit 15, and a straight-ahead control unit 16.

Each of the above functional blocks 11 to 16 can be configured by any of hardware, DSP (Digital Signal Processor), and software. For example, when configured by software, each of the above functional blocks 11 to 16 is actually configured to include a computer CPU, RAM, ROM, etc., and is a program stored in a recording medium such as RAM, ROM, hard disk, or semiconductor memory. Is realized by the operation of.

The first distance detection unit 11 detects the distance to an obstacle by the first distance sensors 101L and 101R installed near both ends in the vehicle width direction. That is, the first distance detection unit 11 detects the front distance on the left side to the obstacle in front of the electric wheelchair 100 based on the output value from the first distance sensor 101L installed on the left side. Further, the first distance detection unit 11 detects the front distance on the right side to the obstacle based on the output value from the first distance sensor 101R installed on the right side.

The second distance detection unit 12 detects the distance to an obstacle by the second distance sensor 102C installed near the center in the vehicle width direction. That is, the second distance detection unit 12 detects the central front distance to the obstacle in front of the electric wheelchair 100 based on the output value from the second distance sensor 102C installed in the center.

The turning control unit 13 controls the left / right turning operation of the electric wheelchair 100 based on the left front distance and the right front distance detected by the first distance detecting unit 11. Specifically, in the turning control unit 13, the left front distance or the right front distance detected by the first distance detection unit 11 is less than the first threshold value, and the left front distance and the right front distance. When the difference from the distance is equal to or greater than the second threshold value, the electric wheelchair 100 is controlled to turn left or right.

The turning control unit 13 turns the electric wheelchair 100 by a predetermined angle when the above turning operation conditions are satisfied. The turning control unit 13 determines whether or not the turning operation condition is satisfied again after one turning operation, and when the turning operation condition is satisfied, the electric wheelchair 100 is turned again by a predetermined angle. The turning control unit 13 repeatedly executes this operation until the turning operation condition is not satisfied.

FIG. 3 is a diagram for explaining conditions for performing a left / right turning operation by the turning control unit 13. FIG. 3 shows a state when the electric wheelchair 100 starts automatic traveling and then approaches a narrow road 200 (for example, an elevator with an open door) to some extent by traveling straight ahead.

As shown in FIG. 3A, the left front distance r _L detected by the first distance detection unit 11 is less than the first threshold value (for example, 50 cm), and the left front distance r _L and the right side. When the difference from the front distance r _R is equal to or greater than the second threshold value (for example, 10 cm), the turning control unit 13 turns the electric wheelchair 100 to the right. As a condition for turning the electric wheelchair 100 to the right, it may be further added that _{the front distance r L} on the left side is shorter than the front distance r _{R on the right side.}

Further, as shown in FIG. 3B, the front distance r _R on the right side detected by the first distance detection unit 11 is less than the first threshold value, and the front distance r _L on the left side and the front distance r on the right side are r. _When the difference from R is equal to or greater than the second threshold value, the turning control unit 13 turns the electric wheelchair 100 to the left. As a condition for turning the electric wheelchair 100 to the left, it may be further added that _{the front distance r R} on the right side is shorter than the front distance r _{L on the left side.}

When the electric wheelchair 100 is traveling in the narrow road 200, it is preferable to finely control the turning operation to the left and right. Therefore, the threshold value changing unit 14 _{determines whether or not the left front distance r L} and the right front distance r _R detected by the first distance detecting unit 11 are both less than the third threshold value (for example, 50 cm). However, if both are less than the third threshold value, it is determined that the electric wheelchair 100 is in the narrow road 200, and the first threshold value is changed to a smaller value. For example, the first threshold is changed from 50 cm to 10 cm.

The stop control unit 15 controls the stop operation of the electric wheelchair 100 based on at least the central forward distance detected by the second distance detection unit 12. For example, the stop control unit 15 stops the electric wheelchair 100 when the central front distance detected by the second distance detection unit 12 is less than 10 cm.

FIG. 4 is a diagram for explaining the conditions for stopping the electric wheelchair 100 by the stop control unit 15. FIG. 4 shows a state when the electric wheelchair 100 approaches the front wall surface as a result of entering the narrow road 200 (for example, an elevator with an open door) and automatically traveling. As shown in FIG. 4, the stop control unit 15 stops the electric wheelchair 100 when the _{central front distance r C detected by the second distance detection unit 12 is less than 10 cm.}

_{In addition to the central front distance r C} detected by the second distance detection unit 12, the stop control unit 15 has _{a left front distance r L} and a right front distance detected by the first distance detection unit 11. The stopping operation of the electric wheelchair 100 may be controlled based on r _R. For example, in the stop control unit 15, is two or more of the three _{forward distances r L} , r _R , and r _C detected by the first distance detection unit 11 and the second distance detection unit 12 less than 20 cm? , If any one of them is less than 10 cm, the electric wheelchair 100 is stopped.

The straight-ahead control unit 15 controls the electric wheelchair 100 to travel straight when neither the left-right turning operation condition by the turning control unit 13 nor the stopping condition by the stop control unit 15 is satisfied.

FIG. 5 is a flowchart showing an operation example of the automatic driving control device according to the first embodiment configured as described above. The flowchart shown in FIG. 5 starts when the user presses an automatic driving start button (not shown) by the automatic driving control device to instruct the start of automatic driving control.

First, the straight-ahead control unit 15 controls the electric wheelchair 100 to travel straight-ahead (step S1). Next, the first distance detection unit 11 detects the left and right forward distances r _L and r _{R based} on the output values from the first distance sensors 101L and 101R (step S2). _{Here, the turning control unit 13 determines whether or not the left front distance r L} detected by the first distance detection unit 11 is less than the first threshold value (for example, 50 cm) (step S3).

When the left front distance r _L is less than the first threshold value, the turning control unit 13 determines _{that the difference between the left front distance r L} and the right front distance r _R is greater than or equal to the second threshold value (for example, 10 cm). It is further determined whether or not there is (step S4). Here, if the difference between the front distance r _L on the left side and the front distance r _R on the right side is not equal to or greater than the second threshold value, the process proceeds to step S13. On the other hand, _{when the difference between the left front distance r L} and the right front distance r _R is equal to or greater than the second threshold value, the turning control unit 13 has the left front distance r _L shorter than the right front distance r _R. Whether or not it is further determined (step S5).

Here, if the front distance r _L on the left side is not shorter than the front distance r _R on the right side, the process proceeds to step S13. On the other hand, when the front distance r _L on the left side is shorter than the front distance r _R on the right side, the turning control unit 13 stops the straight running of the electric wheelchair 100 and moves the electric wheelchair 100 to the right by a predetermined angle on the spot. Turn (step S6). After that, after the left and right forward distances r _L and r _R are detected by the first distance detecting unit 11 (step S7), the process returns to step S3. As a result, the right turn operation is continued in step S6 until the right turn conditions of steps S3 to S5 are no longer satisfied.

When it is determined in step S3 that the left front distance r _L is not less than the first threshold value, the turning control unit 13 has the right front distance r _R detected by the first distance detection unit 11. It is determined whether it is less than the threshold value of 1 (step S8). Here, if the forward distance r _R on the right side is not less than the first threshold value, the process proceeds to step S13. On the other hand, when the front distance r _R on the right side is less than the first threshold value, the turning control unit 13 determines whether or not the difference between _{the front distance r L} on the left side and the front distance r _{R on the right side is greater than or equal to the second threshold value.} Is further determined (step S9).

Here, if the difference between the front distance r _L on the left side and the front distance r _R on the right side is not equal to or greater than the second threshold value, the process proceeds to step S13. On the other hand, _{when the difference between the left front distance r L} and the right front distance r _R is equal to or greater than the second threshold value, the turning control unit 13 has the right front distance r _R shorter than the left front distance r _L. Whether or not it is further determined (step S10). Then, if the front distance r _R on the right side is not shorter than the front distance r _L on the left side, the process proceeds to step S13.

On the other hand, when the front distance r _R on the right side is shorter than the front distance r _L on the left side, the turning control unit 13 stops the straight running of the electric wheelchair 100 and moves the electric wheelchair 100 to the left by a predetermined angle on the spot. Turn (step S11). After that, after the left and right forward distances r _L and r _R are detected by the first distance detecting unit 11 (step S12), the process returns to step S8. As a result, the left turn operation is continued in step S11 until the left turn conditions of steps S8 to S10 are no longer satisfied.

When neither the right turning condition of steps S3 to S5 nor the left turning condition of steps S8 to S10 is satisfied, the threshold value changing unit 14 determines the left front distance r _L and the right side detected by the first distance detecting unit 11. It is determined whether or not the forward distance r _{R of the above} is less than the third threshold value (for example, 50 cm) (step S13). If both are less than the third threshold value, the threshold value changing unit 14 changes the first threshold value from 50 cm to 10 cm (step S14). On the other hand, _{if either the left front distance r L} or the right front distance r _R is equal to or greater than the third threshold value, the threshold value change process in step S14 is not performed.

Then, the second distance detection unit 12 detects the forward distance _{r C} of the center by the output value of the second distance sensor 102C (step S15). _{Then, the stop control unit 15 determines whether or not the central front distance r C} detected by the second distance detection unit 12 is less than 10 cm (step S16). If the central front distance r _C is not less than 10 cm, the process returns to step S1 and causes the electric wheelchair 100 to travel straight. On the other hand, when the central front distance r _C is less than 10 cm, the stop control unit 15 stops the electric wheelchair 100 (step S17). As a result, the processing of the flowchart shown in FIG. 5 is completed.

As described in detail above, in the first embodiment, the first distance sensors 101L and 101R having narrow directivity in which the spread angle of the transmitted signal is equal to or less than a predetermined value are provided near both ends of the electric wheelchair 100 in the vehicle width direction. A signal is transmitted from the distance sensors 101L and 101R toward the front of the electric wheelchair 100. Then, the turning motion of the electric wheelchair 100 to the left and right is controlled based on the left front distance and the right front distance to the obstacle detected by the first distance sensors 101L and 101R, respectively.

According to the first embodiment configured in this way, the left and right first distance sensors 101L and 101R having narrow directivity are used to reach an obstacle in a narrow region on the extension line from the vicinity of the left end of the electric wheelchair 100 to the front. The distance (front distance on the left side) and the distance from the vicinity of the right end of the electric wheelchair 100 to an obstacle in a narrow region on the extension line to the front (front distance on the right side) are individually detected. Therefore, when the electric wheelchair 100 is traveling toward the narrow road 200, it is traveling toward the narrow road 200 instead of one obstacle due to the difference between the front distance on the left side and the front distance on the right side. It is possible to recognize that there is a possibility, and it becomes possible to automatically approach the narrow road 200 by turning left and right.

When the electric wheelchair 100 is in the narrow road 200 and is traveling at a position close to the side wall, it is conceivable that the wheelchair 100 is controlled to turn in the direction of the side wall while satisfying the left and right turning operation conditions. FIG. 6 shows a state in which the electric wheelchair 100 is traveling in a position close to the right side wall in the narrow road 200. In this case, the first distance sensor 101R on the right side cannot accurately measure the front distance on the right side, and it is erroneously determined that the rightward turning operation condition shown in FIG. 3A is satisfied. It may end up. In this case, if the electric wheelchair 100 is turned to the right, the electric wheelchair 100 collides with the right side wall.

In order to avoid such inconvenience, it may be configured as follows. That is, as shown in FIG. 7, third distance sensors 103L and 103R are further provided on the left and right sides of the electric wheelchair 100, and signals are transmitted toward the left and right sides of the electric wheelchair 100. The third distance sensors 103L and 103R are for detecting obstacles existing on the left and right sides of the electric wheelchair 100, and for example, an ultrasonic sensor can be used. As the third distance sensors 103L and 103R, the same sensors as the first distance sensors 101L and 101R may be used.

Further, as shown in FIG. 8, the automatic traveling control device further includes a third distance detecting unit 17 as its functional configuration, and also includes a turning control unit 13A in place of the turning control unit 13. The third distance detection unit 17 detects the left-side distance and the right-side distance to the obstacle by the third distance sensors 103L and 103R on the left and right sides, respectively.

Even when the turning control unit 13A satisfies the left / right turning operation condition, either the left side distance or the right side distance detected by the third distance detecting unit 17 is a fourth threshold value (for example, 10 cm). If it is less than, control is performed so that the turning motion to the left or right is not performed. By doing so, it is possible to avoid the inconvenience of turning the electric wheelchair 100 in the direction of the side wall in the narrow road 200.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to the drawings. In the second embodiment, the method of installing the distance sensor on the electric wheelchair 100 is the same as that in FIG. 1 or FIG. The laser range finder used as the first distance sensors 101L and 101R is a sensor that utilizes extremely strong straightness of light. Therefore, if the distance measuring surface is a wall made of a glossy aluminum material, a mirror, or the like, the distance measuring may not be possible due to the reflection of light rays or the like. The second embodiment enables automatic approaching to the narrow road 200 by turning left and right even when a distance measurement error occurs in any of the first distance sensors 101L and 101R. It is a thing.

FIG. 9 is a block diagram showing a functional configuration example of the automatic driving control device according to the second embodiment. Note that, in FIG. 9, those having the same reference numerals as those shown in FIG. 2 have the same functions, and therefore, duplicate description will be omitted here. The automatic traveling control device according to the second embodiment further includes a distance measuring error determination unit 18, and also includes a turning control unit 13B in place of the turning control unit 13.

The distance measurement error determination unit 18 determines whether or not the left front distance or the right front distance detected by the first distance detection unit 11 indicates an error value. The case where the error value is shown is when the output from the first distance sensors 101L and 101R is an error, and when the output value from the first distance sensors 101L and 101R is a value outside the specifications. Includes both.

The turning control unit 13B makes an error when the distance measuring error determination unit 18 determines that either the left front distance or the right front distance indicates an error value during the execution of the turning operation to the left or right. The turning operation is continued until the flag is turned ON and the distance measuring error determination unit 18 determines that the left / right turning operation condition is not satisfied and the error value is not indicated.

When the turning control unit 13B stops the turning operation to the left or right, if the error flag is ON, the turning control unit 13B performs the turning operation in the direction opposite to the direction of the turning operation up to that point. Then, based on the left front distance or the right front distance detected as a value other than an error value by the first distance detection unit 11 during the turning operation in the opposite direction, the stopping direction of the turning operation of the electric wheelchair 100 To determine.

FIG. 10 is a diagram for explaining an operation example of the distance measuring error determination unit 18 and the turning control unit 13B. FIG. 10A shows a state in which the left turning operation condition is satisfied and the left turning is started at a certain time point T0. FIG. 10B shows a state after the electric wheelchair 100 turns to the left by a predetermined angle from the state of FIG. 10A at the next time point T1.

In FIG. 10B, the laser beam emitted from the first distance sensor 101R on the right side hits a mirror installed on the inner wall surface in the narrow road 200 and is detected by the first distance detection unit 11. The front distance on the right side indicates the error value. In this case, the turning control unit 13B turns on the error flag and further continues the turning operation to the left.

FIG. 10 (c) shows a state after the electric wheelchair 100 turns to the left by a predetermined angle from the state of FIG. 10 (b) at the next time point T2. Here, it is determined by the turning control unit 13B that the turning operation condition to the left is not satisfied, and it is determined by the distance measuring error determination unit 18 that the front distance on the right side does not indicate an error value. In this case, the turning control unit 13B stops the turning operation to the left.

After stopping the turning operation to the left, the turning control unit 13B performs the turning operation in the right direction opposite to the previous turning direction, as shown in FIGS. 10 (d) and 10 (e). At this time, the turning control unit 13B sequentially turns the electric wheelchair 100 at each angle at which the electric wheelchair 100 faces a direction different from that in FIGS. 10A and 10B.

10 (d) faces the direction between the direction in which the electric wheelchair 100 was facing at the time point T1 in FIG. 10 (b) and the direction in which the electric wheelchair 100 was facing at the time point T2 in FIG. 10 (c). It shows a state in which the electric wheelchair 100 is turned at an angle. In this case, the front distance on the left does not indicate an error value.

10 (e) faces the direction between the direction in which the electric wheelchair 100 was facing at the time point T0 in FIG. 10 (a) and the direction in which the electric wheelchair 100 was facing at the time point T1 in FIG. 10 (b). It shows a state in which the electric wheelchair 100 is turned at an angle. Again, the left front distance does not indicate an error value.

The turning control unit 13B has a left front distance or a right front detected as a value that is not an error value by the first distance detecting unit 11 during the turning operation in the opposite direction shown in FIGS. 10 (d) and 10 (e). Based on the distance, the stopping direction of the turning operation of the electric wheelchair 100 is determined. For example, when the turning operation in the reverse direction is a right turning, the direction in which the front distance on the left side is maximized, that is, the direction shown in FIG. 10E is determined as the stopping direction of the turning operation. As a result, the straight-ahead control unit 15 controls to perform straight-ahead travel from the state shown in FIG. 10 (e).

In the example of FIG. 10, the turning control unit 13B performs a turning operation in the opposite direction once between each direction when the turning operation is performed in the forward direction shown in FIGS. 10 (a) to 10 (c). However, it may be done multiple times. Further, the number of divisions between each direction when the turning operation is performed in the forward direction may be determined based on a predetermined rule. For example, in FIG. 10C, when the turning operation is stopped, the left and right front distances (for example, the longer front distance of the left and right) detected by the first distance detection unit 11 and the distance measurement error are detected. It is possible to determine the number of divisions from the table information based on the number of times (1 time in the case of FIG. 10). This table information is set in advance according to the vehicle characteristics of the electric wheelchair 100.

Further, here, the turning operation is stopped in the direction in which the front distance on the left side or the front distance on the right side, which is detected as a value other than an error value by the first distance detecting unit 11 during the turning operation in the reverse direction, is maximized. Although it was decided to determine the direction, the present invention is not limited to this. For example, the direction in which the difference between the front distance on the left side and the front distance on the right side is minimized may be determined as the stopping direction of the turning operation.

FIG. 11 is a flowchart showing an operation example of the automatic driving control device according to the second embodiment. In the flowchart shown in FIG. 11, it means that the same process is executed at the same step number as the step number shown in FIG.

First, the straight-ahead control unit 15 controls the electric wheelchair 100 to travel straight-ahead (step S1). Next, the first distance detection unit 11 detects the left and right forward distances r _L and r _{R based} on the output values from the first distance sensors 101L and 101R (step S2). Here, the turning control unit 13B determines whether or not the error flag is ON (step S21). Then, when the error flag is not turned ON, the turning control unit 13B determines whether or not the turning operation condition to the right shown in steps S3 to S5 of FIG. 5 is satisfied (step S22).

When the rightward turning operation condition is satisfied, the turning control unit 13B stops the straight running of the electric wheelchair 100 and turns the electric wheelchair 100 to the right by a predetermined angle on the spot (step S6). Then, when the right turn of a predetermined angle is performed in this way, the first distance detection unit 11 detects the left and right forward distances r _L , r _{R based} on the output values of the first distance sensors 101L, 101R. (Step S7).

Here, the ranging error determination unit 18 _{determines whether or not the detected front distance r L} on the left side or the front distance r _R on the right side indicates an error value (step S23). When any of the forward distances indicates an error value, the turning control unit 13B turns on the error flag and counts up the number of occurrences of the distance measurement error (step S24). After that, the process returns to step S6. On the other hand, if it is determined in step S23 that none of the forward distances indicates an error value, the process returns to step S21.

If the distance measurement error is once detected in step S23, and after the right turn is continued by the loop processing in steps S24, S6, S7, and S23, the distance measurement error is no longer detected, the error flag is ON. Therefore, in this case, the process jumps to step S29. On the other hand, when the distance measurement error has not occurred at all, the error flag is not turned ON when returning from step S23 to step S21. In this case, the right turn is continued by the loop processing of steps S21, S22, S6, S7, and S23 until the right turn operation condition is not satisfied.

If it is determined in step S21 that the rightward turning operation condition is not satisfied, the turning control unit 13B determines whether or not the error flag is ON (step S25). Then, when the error flag is not turned ON, the turning control unit 13B determines whether or not the turning operation condition to the left shown in steps S8 to S9 of FIG. 5 is satisfied (step S26). When the condition for turning to the left is satisfied, the turning control unit 13B stops the straight running of the electric wheelchair 100 and turns the electric wheelchair 100 to the left by a predetermined angle on the spot (step S11). Then, when the left turn at a predetermined angle is performed in this way, the first distance detection unit 11 detects the left and right forward distances r _L and r _R (step S12).

Here, the ranging error determination unit 18 _{determines whether or not the detected front distance r L} on the left side or the front distance r _R on the right side indicates an error value (step S27). When any of the forward distances indicates an error value, the turning control unit 13B turns on the error flag and counts up the number of occurrences of the distance measurement error (step S28). After that, the process returns to step S11. On the other hand, if it is determined in step S27 that none of the forward distances indicates an error value, the process returns to step S25.

If the distance measurement error is once detected in step S27, the left turn is continued by the loop processing in steps S28, S11, S12, and S27, and then the distance measurement error is no longer detected, the error flag is ON. Therefore, in this case, the process jumps to step S29. On the other hand, when the distance measurement error has not occurred at all, the error flag is not turned ON when returning from step S27 to step S25. In this case, the right turn is continued by the loop processing of steps S25, S26, S11, S12, and S27 until the turning operation condition in the left-right direction is not satisfied.

In step S29, the turning control unit 13B turns in the forward direction based on the left and right forward distances detected by the first distance detecting unit 11 when the turning operation is stopped and the number of times the distance measurement error is detected. The number of divisions to be divided between each direction during operation is determined from the table information.

After that, the turning control unit 13B turns off the error flag, clears the number of occurrences of the distance measurement error to zero (step S30), and then sets the electric wheelchair 100 by an angle corresponding to the number of divisions determined in step S29. Turn in the opposite direction (step S31). Then, the first distance detection unit 11 _{detects and stores the left and right forward distances r L} and r _R (step S32).

Next, the turning control unit 13B determines whether or not the turning operation has been performed for all the angles corresponding to the number of divisions determined in step S29 (step S33). If the turning operation for all the angles according to the number of divisions has not been completed, the process returns to step S31.

On the other hand, when the turning operation for all the angles according to the number of divisions is completed, the turning control unit 13B is detected by the first distance detecting unit 11 at each angle in step S32 as a value other than an error value on the left side. The stopping direction of the turning operation of the electric wheelchair 100 is determined based on the front distance or the front distance on the right side (step S34). After that, the process proceeds to step S13. Further, even if it is determined in step S22 that the turning operation condition to the right is not satisfied and the turning operation condition to the left is not satisfied in step S26, the process proceeds to step S13. The processing after step S13 is the same as in FIG.

As described in detail above, according to the second embodiment, when the laser range finder is used as the first distance sensors 101L, 101R, the first distance sensors 101L, 101R are reflected by the reflection of light rays on the distance measuring surface. Even if a distance measurement error occurs in any of the above, the vehicle can automatically approach the narrow road 200 by turning left and right.

(Third Embodiment)
Next, a third embodiment of the present invention will be described with reference to the drawings. The automatic driving control device according to the present embodiment is based on driving the electric wheelchair 100 in a straight line, and if the condition for driving the electric wheelchair 100 is not satisfied (when the turning operation condition is satisfied), it is on the spot until the turning operation condition is not satisfied. The operation of turning at the wheelchair to change the traveling direction and then traveling straight ahead is repeated to automatically approach the narrow road 200. On the other hand, as shown in FIG. 12, when the electric wheelchair 100 enters the narrow road 200 at an acute angle, a large change in the vehicle direction is required, which may lead to a burden on the occupants (ride comfort, fear, etc.). There is sex. The third embodiment controls the electric wheelchair 100 so as not to enter the narrow road 200 at an acute angle as much as possible.

In the third embodiment, the method of installing the distance sensor on the electric wheelchair 100 is the same as that in FIG. 1 or FIG. FIG. 13 is a block diagram showing a functional configuration example of the automatic traveling control device according to the third embodiment. Note that, in FIG. 13, those having the same reference numerals as those shown in FIG. 2 have the same functions, and therefore, duplicate description will be omitted here. The automatic traveling control device according to the third embodiment includes a turning control unit 13C instead of the turning control unit 13.

When the start of automatic running is instructed, the turning control unit 13C turns the electric wheelchair 100 to a certain angle by a predetermined angle in the left direction and the right direction, respectively, and makes a first distance during the turning operation to the left and right. The straight-ahead traveling direction of the electric wheelchair 100 is determined based on the front distance on the left side and the front distance on the right side detected by the detection unit 11.

FIG. 14 is a diagram for explaining an operation example of the turning control unit 13C according to the third embodiment. FIG. 14A shows a state when the start of automatic driving is instructed. 14 (b) and 14 (c) show a state in which the electric wheelchair 100 is swiveled to the right from the state of FIG. 14 (a) to a constant angle (for example, 15 degrees) by a predetermined angle. The first distance detection unit 11 detects the left and right forward distances in each of the states of FIGS. 14 (b) and 14 (c).

14 (d) and 14 (e) show a state in which the electric wheelchair 100 is swiveled to the left from the state of FIG. 14 (a) to a constant angle (for example, 15 degrees) by a predetermined angle. The first distance detection unit 11 detects the left and right forward distances in each of the states of FIGS. 14 (d) and 14 (e).

The turning control unit 13C has a left front distance and a right front distance detected by the first distance detection unit 11 in each direction from the directions of the electric wheelchair 100 shown in FIGS. 14 (b) to 14 (e). Based on the above, the direction in which the approach angle with respect to the narrow road 200 is the obtuse angle is determined as the straight-ahead traveling direction of the electric wheelchair 100.

For example, the turning control unit 13C determines the direction in which the front distance on the left side and the front distance on the right side are the longest as the straight-ahead traveling direction of the electric wheelchair 100. Alternatively, the direction in which the front distance on the left side and the front distance on the right side are the longest and the difference between the front distance on the left side and the front distance on the right side is the smallest is determined as the straight-ahead traveling direction of the electric wheelchair 100. good. In the example of FIG. 14, the direction shown in FIG. 14E is determined as the straight-ahead traveling direction of the electric wheelchair 100.

As described in detail above, according to the third embodiment, when the start of automatic driving of the electric wheelchair 100 is instructed, the electric wheelchair 100 travels straight so as to enter the narrow road 200 at an obtuse angle as much as possible. The direction is determined. As a result, when the electric wheelchair 100 approaches the narrow road 200 by traveling straight ahead, it is not necessary to make a large change in the vehicle direction, and the burden on the occupant can be reduced.

In the first to third embodiments, the case where the automatic approach running to the narrow road 200 where the back is a dead end such as an elevator is described as an example has been described, but the back is a dead end. It goes without saying that it is possible to perform automatic approaching to a narrow passage.

Further, in the first to third embodiments, an example in which a laser range finder is used as the first distance sensors 101L and 101R has been described, but the present invention is not limited thereto. For example, a LIDAR (Laser Imaging Detection and Ranging) sensor, a TOF (Time of Flight) camera, a stereo camera, or the like may be used as the first distance sensors 101L, 101R. It is preferable to use a laser range finder because it is the cheapest.

Further, in the first to third embodiments described above, an example in which the electric wheelchair 100 is used has been described, but the present invention is not limited thereto. The first to third embodiments can be applied to any of the electric vehicles capable of controlling the left and right wheels independently.

In addition, the first to third embodiments are merely examples of embodiment of the present invention, and the technical scope of the present invention should be construed in a limited manner. It is something that does not become. That is, the present invention can be implemented in various forms without departing from its gist or its main features.

11 1st distance detection unit 12 2nd distance detection unit 13, 13A, 13B, 13C Swivel control unit 14 Threshold change unit 15 Stop control unit 16 Straight control unit 17 3rd distance detection unit 18 Distance measurement error determination unit 100 Electric wheelchair 101L, 101R 1st distance sensor 102C 2nd distance sensor 103L, 103R 3rd distance sensor 200 Narrow road

Claims (8)

It is an automatic driving control device that controls the automatic driving of electric vehicles.
Distance sensors having narrow directivity such that the spread of the transmitted signal is equal to or less than the sensor width are provided near both ends in the vehicle width direction of the electric vehicle, and the distance sensor transmits the signal toward the front of the electric vehicle. So
A distance detection unit that detects the distance to an obstacle by the distance sensors near both ends in the vehicle width direction, and
The left front distance or the right front distance detected by the distance detection unit is less than the first threshold value, and the difference between the left front distance and the right front distance is equal to or more than the second threshold value. In some cases, a turning control unit that controls the electric vehicle to turn left or right ,
It is determined whether or not the front distance on the left side and the front distance on the right side detected by the distance detection unit are both less than the third threshold value, and when both are less than the third threshold value, the first An automatic traveling control device for an electric vehicle, which comprises a threshold value changing unit for changing the threshold value of the above to a smaller value. It is an automatic driving control device that controls the automatic driving of electric vehicles.
Distance sensors having narrow directivity such that the spread of the transmitted signal is equal to or less than the sensor width are provided near both ends in the vehicle width direction of the electric vehicle, and the distance sensor transmits the signal toward the front of the electric vehicle. So
Third distance sensors are provided on the left and right sides of the electric vehicle so as to transmit signals toward the left and right sides of the electric vehicle.
A distance detection unit that detects the distance to an obstacle by the distance sensors near both ends in the vehicle width direction, and
A third distance detection unit that detects the left-side distance and the right-side distance to the obstacle by the third distance sensor on the left and right sides, respectively.
Based on the forward distance and right front distance left to be detected by the distance detection unit, e Bei a turning control unit for controlling the pivoting movement to the left and right of the electric vehicle,
Even when the turning control unit satisfies the left / right turning operation condition, either the left side distance or the right side distance detected by the third distance detecting unit is less than the fourth threshold value. In this case, an automatic traveling control device for an electric vehicle, which is characterized in that it is controlled so as not to perform the above-mentioned turning operation to the left and right. It is an automatic driving control device that controls the automatic driving of electric vehicles.
Distance sensors having narrow directivity such that the spread of the transmitted signal is equal to or less than the sensor width are provided near both ends in the vehicle width direction of the electric vehicle, and the distance sensor transmits the signal toward the front of the electric vehicle. So
A distance detection unit that detects the distance to an obstacle by the distance sensors near both ends in the vehicle width direction, and
A turning control unit that controls the left / right turning operation of the electric vehicle based on the left front distance and the right front distance detected by the distance detecting unit .
When the front distance on the left side or the front distance on the right side detected by the distance detection unit is an error in the output from the distance sensor, and when the output value from the distance sensor is a value outside the specifications. It is provided with a distance measurement error determination unit that determines whether or not an error value indicating at least one of the above is indicated.
When the ranging error determination unit determines that either the left front distance or the right front distance indicates the error value during the left / right turning operation, the turning control unit Stops the turning operation at the time when the distance measuring error determination unit determines that the turning operation condition to the left and right is not satisfied and the error value is not shown, and then turns in the opposite direction. The turning operation of the electric vehicle is based on the left front distance or the right front distance detected by the distance detection unit as a value other than the error value during the turning operation in the opposite direction. An automatic travel control device for an electric vehicle, which is characterized by determining a stop direction. It is an automatic driving control device that controls the automatic driving of electric vehicles.
Distance sensors having narrow directivity such that the spread of the transmitted signal is equal to or less than the sensor width are provided near both ends in the vehicle width direction of the electric vehicle, and the distance sensor transmits the signal toward the front of the electric vehicle. So
A distance detection unit that detects the distance to an obstacle by the distance sensors near both ends in the vehicle width direction, and
Based on the forward distance and right front distance left to be detected by the distance detection unit, e Bei a turning control unit for controlling the pivoting movement to the left and right of the electric vehicle,
When the start of automatic driving is instructed, the turning control unit turns the electric vehicle to a certain angle by a predetermined angle in each of the left and right directions, and the distance detecting unit during the turning operation to the left and right. An automatic traveling control device for an electric vehicle, characterized in that the straight traveling direction of the electric vehicle is determined based on the front distance on the left side and the front distance on the right side detected by the above. A second distance sensor is further provided near the center of the electric vehicle in the vehicle width direction, and a signal is transmitted from the second distance sensor toward the front of the electric vehicle.
A second distance detection unit that detects the distance to the obstacle by the second distance sensor, and
Any of claims 1 to 4 , further comprising a stop control unit that controls the stop operation of the electric vehicle based on at least the central front distance detected by the second distance detection unit. The automatic driving control device for an electric vehicle according to item 1. In addition to the central front distance detected by the second distance detection unit, the stop control unit is electrically driven based on the left front distance and the right front distance detected by the distance detection unit. The automatic traveling control device for an electric vehicle according to claim 5 , wherein the stopping operation of the vehicle is controlled. It is an automatic driving control method that automatically controls the driving of an electric vehicle equipped with distance sensors having narrow directivity so that the spread of the transmitted signal is equal to or less than the sensor width near both ends in the vehicle width direction.
By transmitting the signal from the distance sensors near both ends in the vehicle width direction toward the front of the electric vehicle, the distance detection unit of the automatic control device mounted on the electric vehicle can reach the obstacle in front of the vehicle. The first step to detect
A second step in which the turning control unit of the automatic control device controls the left / right turning operation of the electric vehicle based on the left front distance and the right front distance detected by the distance detecting unit .
While the left / right turning operation condition is satisfied in the second step and the left / right turning operation is being executed, the distance measurement error determination unit of the automatic control device is detected by the distance detection unit in front of the left side. Whether the distance or the front distance on the right side indicates an error value indicating at least one of the case where the output from the distance sensor is an error and the value output from the distance sensor is a value out of specification. The third step to determine whether
When the ranging error determination unit determines that either the left front distance or the right front distance indicates the error value during the left / right turning operation, the turning control unit However, when the distance measuring error determination unit determines that the turning operation condition to the left and right is not satisfied and the error value is not shown, the turning operation is stopped and then the turning is performed in the opposite direction. The turning operation of the electric vehicle is based on the left front distance or the right front distance detected by the distance detection unit as a value other than the error value during the turning operation in the opposite direction. An automatic traveling control method for an electric vehicle, which comprises a fourth step of determining a stop direction. It is an automatic driving control method that automatically controls the driving of an electric vehicle equipped with distance sensors having narrow directivity so that the spread of the transmitted signal is equal to or less than the sensor width near both ends in the vehicle width direction.
When the start of automatic running is instructed, the turning control unit of the automatic control device mounted on the electric vehicle turns the electric vehicle leftward and rightward by a predetermined angle, respectively, to the left. The left side detected by the distance detection unit of the automatic control device by transmitting the signal toward the front of the electric vehicle from the distance sensors near both ends in the vehicle width direction during the turning operation in the direction and the right direction. The first step of determining the straight-ahead traveling direction of the electric vehicle based on the front distance of the above and the front distance of the right side, and
After starting the straight running of the electric vehicle, by transmitting the signal toward from the distance sensor in the vicinity of the vehicle widthwise ends in front of the electric vehicle, the upper Ki距separation detecting section, the front of the obstacle The second step to detect the distance to
Upper Ki旋times control unit, on the basis of the forward distance and right front distance left to be detected by the distance detection unit, that a third step of controlling the swing motion to the left and right of the electric vehicle A characteristic automatic driving control method for electric vehicles.

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