JP7788331B2 - Rollover prevention device - Google Patents

Description

The present invention relates to a rollover prevention device.

Patent Document 1 describes a rollover prevention device that prevents dump trucks from overturning. When the dump operation switch is turned on, this rollover prevention device compares the tilt angle detected by a sensor that detects the tilt angle in the dump truck's width direction with a preset allowable rollover tilt angle. If the tilt angle detected by the sensor is equal to or greater than the allowable rollover tilt angle, a warning signal is output.

Japanese Utility Model Application Publication No. 63-094051

However, with the technology described in Patent Document 1, if the sensor fails for some reason, there is a possibility that the tilt angle detected by the sensor will not be equal to or greater than the allowable rollover tilt angle, even if the actual tilt angle of the dump truck is equal to or greater than the allowable rollover tilt angle. As a result, the loading platform may be dumped up without an alarm signal being output, which could cause the dump truck to overturn.

Therefore, the objective of the present invention is to provide a rollover prevention device that can more reliably prevent dump vehicles from rolling over.

The rollover prevention device of the present invention is designed to prevent a dump vehicle having a mounting device mounted on the vehicle body for raising and lowering the loading platform from rolling over. It includes a first sensor and a second sensor that measure the inclination of the dump vehicle, and a check unit that determines whether the first sensor and the second sensor have malfunctioned. The check unit determines that at least one of the first sensor and the second sensor has malfunctioned when the difference between the detection value of the first sensor and the detection value of the second sensor exceeds a threshold value.

This rollover prevention device is equipped with two sensors, a first sensor and a second sensor, that measure the inclination of the dump vehicle. If the difference between the detection value of the first sensor and the detection value of the second sensor exceeds a threshold, it is determined that at least one of the first sensor and the second sensor has failed. This allows for highly accurate determination of failure of the first sensor or the second sensor, thereby more reliably preventing rollover of the dump vehicle.

The first sensor may be a sensor attached to the vehicle frame and measure the inclination of the vehicle body, and the second sensor may be a sensor attached to the loading platform and measure the inclination of the loading platform as it is raised or lowered relative to the vehicle body. In this rollover prevention device, the first sensor is attached to the vehicle frame and measures the inclination of the vehicle body, thereby improving the accuracy of measuring the inclination of the dump vehicle by the first sensor. Meanwhile, the second sensor is attached to the loading platform and measures the inclination of the loading platform as it is raised or lowered relative to the vehicle body, so it can measure the inclination of the vehicle body relative to the ground when the loading platform is level, and can measure the inclination of the loading platform relative to the vehicle body when the loading platform is tilted. In this way, the second sensor can independently measure not only the inclination of the loading platform but also the inclination of the vehicle body when the loading platform is level, so the checking unit can determine failure of the first and second sensors when the loading platform is level. This prevents an increase in the number of sensors on the entire dump vehicle.

The dump vehicle is an autonomously driven vehicle that operates autonomously to raise and lower the loading bed, and the check unit may determine whether the first and second sensors are malfunctioning before the dump vehicle begins operation. In this rollover prevention device, when the dump vehicle is an autonomously driven vehicle that operates autonomously to raise and lower the loading bed, the check unit determines whether the first and second sensors are malfunctioning before the dump vehicle begins operation. Therefore, if the first sensor or second sensor is malfunctioning, it is possible to prevent the dump vehicle from operating and raising or lowering the loading bed.

This invention makes it possible to more reliably prevent dump vehicles from overturning.

1 is a block diagram showing a rollover prevention device according to a first embodiment; 1 is a schematic diagram showing a dump vehicle equipped with a rollover prevention device according to a first embodiment; 4 is a flowchart illustrating an example of a processing operation of the anti-rollover device according to the first embodiment. FIG. 10 is a block diagram showing a rollover prevention device according to a second embodiment. 10 is a flowchart illustrating an example of a processing operation of the anti-rollover device according to the second embodiment.

Embodiments of the present invention will now be described in detail with reference to the drawings. Note that in the following description, identical or equivalent elements will be designated by the same reference numerals, and duplicate explanations will be omitted.

[First embodiment]
FIG. 1 is a block diagram showing a rollover prevention device 1 according to a first embodiment. FIG. 2 is a schematic diagram showing a dump vehicle 5 equipped with the rollover prevention device 1 according to the first embodiment. As shown in FIGS. 1 and 2 , the rollover prevention device 1 according to this embodiment is a device for preventing a dump vehicle 5 having a mounting device 3 mounted on a vehicle body 4 for raising and lowering a loading platform 2 from rolling over. Raising the loading platform 2 is referred to as dump-up, and lowering the loading platform 2 is referred to as dump-down. The dump vehicle 5 may be a vehicle driven by a driver and operated to raise and lower the loading platform 2, or may be an autonomous vehicle that operates autonomously and raises and lowers the loading platform 2. The autonomous vehicle automatically drives to a loading and unloading site for soil and sand, for example, according to a preset schedule, and automatically raises and lowers the loading platform 2 at the site.

When the bed 2 of a dump vehicle 5 is raised, the center of gravity of the dump vehicle 5 becomes higher. Therefore, if the inclination of the dump vehicle 5 exceeds a threshold, there is a possibility that the dump vehicle 5 will overturn when the bed 2 is raised. The inclination of the dump vehicle 5 is expressed, for example, as the inclination angle relative to the vertical direction (direction of gravity). Furthermore, the inclination of the dump vehicle 5 is, for example, the inclination in the vehicle width direction of the dump vehicle 5.

The rollover prevention device 1 therefore measures the inclination of the dump vehicle 5 to prevent the dump vehicle 5 from overturning when the loading platform 2 is raised. In other words, by measuring the inclination of the dump vehicle 5, it is possible to estimate whether the dump vehicle 5 will overturn when the loading platform 2 is raised, and if it is estimated that the dump vehicle 5 will overturn when the loading platform 2 is raised, rollover prevention processing can be performed to prevent the dump vehicle 5 from overturning when the loading platform 2 is raised. This makes it possible to prevent the dump vehicle 5 from overturning when the loading platform 2 is raised. The rollover prevention processing will be described later.

The rollover prevention device 1 includes a first sensor 11, a second sensor 12, and a control unit 13.

The first sensor 11 is a sensor that measures the inclination of the dump vehicle 5. The second sensor 12 is a sensor that measures the inclination of the dump vehicle 5. In other words, the rollover prevention device 1 is equipped with two sensors, the first sensor 11 and the second sensor 12, that measure the inclination of the dump vehicle 5.

The first sensor 11 and the second sensor 12 are attached to either the vehicle body 4 or the mounting device 3 of the dump vehicle 5 to measure the inclination of the dump vehicle 5. The first sensor 11 and the second sensor 12 may be attached to only one of the vehicle body 4 or the mounting device 3, or may be attached separately to the vehicle body 4 and the mounting device 3. In this embodiment, as an example, the first sensor 11 is attached to the frame 6 of the vehicle body 4, and the second sensor 12 is attached to the loading platform 2 of the mounting device 3. The first sensor 11 is a sensor that measures the inclination of the vehicle body 4, and the second sensor 12 is a sensor that measures the inclination of the loading platform 2 that is raised or lowered relative to the vehicle body 4. The second sensor 12 can measure the inclination of the vehicle body 4 relative to the ground when the loading platform 2 is level, and can measure the inclination of the loading platform 2 relative to the vehicle body 4 when the loading platform 2 is tilted. In this way, the second sensor 12 can independently measure not only the inclination of the loading platform 2 but also the inclination of the vehicle body 4. Furthermore, when traveling autonomously, the inclination of the dump vehicle 5 may be measured mainly using the detection value of the first sensor 11, and when raising or lowering the loading platform 2, the inclination of the dump vehicle 5 may be measured mainly using the detection value of the second sensor 12.

The first sensor 11 and the second sensor 12 may be an inclination sensor, an IMU (Inertial Measurement Unit), or the like. The first sensor 11 and the second sensor 12 may be the same type of sensor, or may be different types of sensors. The first sensor 11 and the second sensor 12 being the same type of sensor means, for example, that both the first sensor 11 and the second sensor 12 are inclination sensors or IMUs. The first sensor 11 and the second sensor 12 being different types of sensors means, for example, that the first sensor 11 is either an inclination sensor or an IMU, and the second sensor 12 is the other of either an inclination sensor or an IMU.

The control unit 13 is an electronic control unit (ECU) having, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc. The control unit 13 performs various controls by, for example, loading programs stored in the ROM into the RAM and executing them on the CPU. The control unit 13 may be composed of a single electronic control unit or multiple electronic control units. The control unit 13 may be mounted on the vehicle body 4, on the mounting device 3, or on both the vehicle body 4 and the mounting device 3. When the control unit 13 is mounted on both the vehicle body 4 and the mounting device 3, the control units 13 mounted on the vehicle body 4 and the mounting device 3 perform various controls by communicating with each other via wired or wireless communication.

The control unit 13 has a check unit 14, a rollover determination unit 15, and a rollover prevention processing unit 16.

The check unit 14 determines whether the first sensor 11 and the second sensor 12 are faulty. If the difference between the detection value of the first sensor 11 and the detection value of the second sensor 12 exceeds a threshold, the check unit 14 determines that at least one of the first sensor 11 and the second sensor 12 is faulty. For example, the check unit 14 acquires the detection value of the first sensor 11 and the detection value of the second sensor 12 and calculates the difference between the detection value of the first sensor 11 and the detection value of the second sensor 12. This difference is called the inter-sensor difference. The check unit 14 then determines whether the inter-sensor difference exceeds a threshold. The threshold may be, for example, a threshold value within a range that includes a range caused by detection errors of the first sensor 11 and the second sensor 12. If the check unit 14 determines that the inter-sensor difference does not exceed the threshold, it determines that the first sensor 11 and the second sensor 12 are not faulty. On the other hand, if the check unit 14 determines that the inter-sensor difference exceeds the threshold, it determines that at least one of the first sensor 11 and the second sensor 12 is faulty. The check unit 14 may determine whether the first sensor 11 or the second sensor 12 is faulty, but does not have to determine whether the first sensor 11 or the second sensor 12 is faulty.

The timing at which the check unit 14 determines whether the first sensor 11 and the second sensor 12 have failed is not particularly limited. For example, the check unit 14 may determine whether the first sensor 11 and the second sensor 12 have failed when the dump vehicle 5 is started, before the dump vehicle 5 is started to travel, when the loading platform 2 is level, or before the loading platform 2 is raised. Furthermore, if the dump vehicle 5 is an autonomous vehicle that operates autonomously and raises and lowers the loading platform 2, the check unit 14 may determine whether the first sensor 11 and the second sensor 12 have failed before the dump vehicle 5 starts to travel.

The rollover determination unit 15 determines whether the dump vehicle 5 will roll over when the bed 2 is raised. For example, if the check unit 14 determines that the first sensor 11 and the second sensor 12 are not malfunctioning, the rollover determination unit 15 determines whether at least one of the detection values of the first sensor 11 and the second sensor 12 exceeds the allowable rollover tilt angle. The allowable rollover tilt angle is an arbitrary tilt angle at which the dump vehicle 5 will not roll over when the bed 2 is raised. If the rollover determination unit 15 determines that at least one of the detection values of the first sensor 11 and the second sensor 12 does not exceed the allowable rollover tilt angle, it determines that the dump vehicle 5 will not roll over when the bed 2 is raised. On the other hand, if the rollover determination unit 15 determines that at least one of the detection values of the first sensor 11 and the second sensor 12 exceeds the allowable rollover tilt angle, it determines that the dump vehicle 5 will roll over when the bed 2 is raised.

The rollover prevention processing unit 16 performs rollover prevention processing to prevent the dump vehicle 5 from rolling over when the bed 2 is raised. Examples of rollover prevention processing include processing to output warnings such as audio, images, and vibrations, processing to prevent the bed 2 from being raised, and processing to prevent the dump vehicle 5 from traveling. Furthermore, if the dump vehicle 5 is an autonomous vehicle that operates autonomously and raises and lowers the bed 2, examples of rollover prevention processing include processing to stop or halt the operation of the dump vehicle 5.

Next, an example of the processing operation of the rollover prevention device 1 will be described with reference to Figure 3. Figure 3 is a flowchart showing an example of the processing operation of the rollover prevention device 1 of the first embodiment. Figure 3 shows an example of the processing operation of the rollover prevention device 1 when determining whether the first sensor 11 and the second sensor 12 have failed before the dump vehicle 5, which is an autonomous vehicle, begins operation.

As shown in FIG. 3 , the rollover prevention device 1 first acquires the detection values of the first sensor 11 and the second sensor 12 (step S1). Next, the rollover prevention device 1 calculates the difference between the detection values of the first sensor 11 and the second sensor 12 acquired in step S1 as the inter-sensor difference (step S2). Next, the rollover prevention device 1 determines whether the inter-sensor difference calculated in step S2 exceeds a threshold value (step S3). If it determines that the inter-sensor difference calculated in step S2 exceeds the threshold value (step S3: YES), the rollover prevention device 1 determines that at least one of the first sensor 11 and the second sensor 12 is malfunctioning (step S4) and performs rollover prevention processing (step S5). The rollover prevention processing in step S5 includes, for example, outputting an alarm such as an audio, image, or vibration, and stopping or halting the operation of the dump vehicle 5. The rollover prevention device 1 then temporarily terminates the processing.

If it is determined that the inter-sensor difference calculated in step S2 does not exceed the threshold value (step S3: NO), the rollover prevention device 1 determines that the first sensor 11 and the second sensor 12 are not malfunctioning (step S6), starts operation, and travels autonomously to the site where soil and sand are to be loaded and unloaded (step S7). Then, upon arriving at the site where soil and sand are to be loaded and unloaded, the rollover prevention device 1 determines whether the dump vehicle 5 will roll over when the loading platform 2 is raised (step S8). In step S8, for example, the rollover prevention device 1 determines whether the dump vehicle 5 will roll over when the loading platform 2 is raised based on whether at least one of the detection values of the first sensor 11 and the second sensor 12 exceeds the allowable rollover tilt angle. If it is determined that the dump vehicle 5 will not roll over when the loading platform 2 is raised (step S8: NO), the rollover prevention device 1 automatically raises and lowers the loading platform 2 at the site where soil and sand are to be loaded and unloaded (step S9). The rollover prevention device 1 then temporarily terminates processing.

If it is determined that the dump vehicle 5 will overturn when the loading platform 2 is raised (step S8: YES), the rollover prevention device 1 performs rollover prevention processing (step S10). The rollover prevention processing in step S10 includes, for example, processing to output an alarm such as audio, image, or vibration, and processing to prevent the loading platform 2 from being raised. The rollover prevention device 1 then temporarily terminates processing.

As explained above, the rollover prevention device 1 according to this embodiment is equipped with two sensors, a first sensor 11 and a second sensor 12, that measure the inclination of the dump vehicle 5. If the difference between the detection value of the first sensor 11 and the detection value of the second sensor 12 exceeds a threshold value, it is determined that at least one of the first sensor 11 and the second sensor 12 has failed. This makes it possible to determine with high accuracy whether the first sensor 11 or the second sensor 12 has failed, thereby more reliably preventing the dump vehicle 5 from rolling over.

Furthermore, in this rollover prevention device 1, the first sensor 11 is attached to the frame 6 of the vehicle body 4 and measures the inclination of the vehicle body, thereby improving the accuracy with which the first sensor 11 measures the inclination of the dump vehicle 5. Meanwhile, the second sensor 12 is attached to the loading platform 2 and measures the inclination of the loading platform 2 as it is raised and lowered relative to the vehicle body 4. Therefore, it can measure the inclination of the vehicle body 4 relative to the ground when the loading platform 2 is level, and can measure the inclination of the loading platform 2 relative to the vehicle body 4 when the loading platform 2 is tilted. In this way, the second sensor 12 can independently measure the inclination of not only the loading platform 2 but also the vehicle body 4 when the loading platform 2 is level, so the checking unit 14 can determine whether the first sensor 11 or the second sensor 12 is faulty when the loading platform is level. This prevents an increase in the number of sensors on the entire dump vehicle 5.

In addition, with this rollover prevention device 1, if the dump vehicle 5 is an autonomous vehicle that operates autonomously and raises and lowers the loading platform 2, the check unit 14 determines whether the first sensor 11 and the second sensor 12 are faulty before the dump vehicle 5 operates. Therefore, if the first sensor 11 or the second sensor 12 is faulty, it is possible to prevent the dump vehicle 5 from operating and raising or lowering the loading platform.

[Second embodiment]
4 is a block diagram showing a rollover prevention device 1A of the second embodiment. The rollover prevention device 1A of the second embodiment is basically the same as the rollover prevention device 1 of the first embodiment, and differs from the rollover prevention device 1 of the first embodiment only in that it does not include the rollover determination unit 15 and the rollover prevention processing unit 16 of the first embodiment. Therefore, only the differences from the first embodiment will be described below, and descriptions of the same matters as in the first embodiment will be omitted.
4, the rollover prevention device 1A of the second embodiment includes a first sensor 11, a second sensor 12, and a control unit 13A, and the control unit 13A includes a check unit 14. For this reason, the rollover prevention device 1A of the modified example determines failures of the first sensor 11 and the second sensor 12 by the check unit 14, but does not determine whether the dump vehicle 5 will roll over when the bed 2 is raised, and does not perform rollover prevention processing to prevent the dump vehicle 5 from rolling over when the bed 2 is raised.

Figure 5 is a flowchart showing an example of the processing operation of the rollover prevention device 1A of the second embodiment. As shown in Figure 5, the rollover prevention device 1A of the second embodiment performs steps S1 to S3, similar to the first embodiment. If it is determined that the inter-sensor difference calculated in step S2 exceeds the threshold value (step S3: YES), the rollover prevention device 1 determines that at least one of the first sensor 11 and the second sensor 12 has failed (step S4) and temporarily terminates processing. On the other hand, if it is determined that the inter-sensor difference calculated in step S2 does not exceed the threshold value (step S3: NO), the rollover prevention device 1 determines that the first sensor 11 and the second sensor 12 have not failed (step S6) and temporarily terminates processing.

In this way, in the second embodiment of the rollover prevention device 1A, the check unit 14 can determine whether the first sensor 11 and the second sensor 12 have failed, more reliably preventing the dump vehicle from rolling over. In this case, the determination of whether the dump vehicle 5 will roll over when the bed 2 is raised and the rollover prevention process to prevent the dump vehicle 5 from rolling over when the bed 2 is raised may be performed by another device.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and may be modified or applied to other applications without departing from the spirit of the claims.

1...anti-rollover device, 1A...anti-rollover device, 2...loading platform, 3...mounting device, 4...vehicle body, 5...dump vehicle, 6...frame, 11...first sensor, 12...second sensor, 13...control unit, 13A...control unit, 14...check unit, 15...anti-rollover determination unit, 16...anti-rollover processing unit.

Claims (2)

A rollover prevention device for preventing a dump vehicle having a mounting device for raising and lowering a loading platform mounted on a vehicle body from rolling over,
a rollover prevention processing unit that performs a rollover prevention process to prevent the dump vehicle from rolling over when the loading platform is raised;
a first sensor and a second sensor for measuring the inclination of the dump vehicle;
a check unit that determines whether the first sensor and the second sensor are malfunctioning,
the first sensor is a sensor attached to a frame of the vehicle body and configured to measure an inclination of the vehicle body;
the second sensor is a sensor attached to the loading platform and configured to measure an inclination of the loading platform as it is raised or lowered relative to the vehicle body;
the checking unit determines that at least one of the first sensor and the second sensor is faulty when a difference between the detection value of the first sensor and the detection value of the second sensor exceeds a threshold value;
the rollover prevention processing unit performs the rollover prevention processing when the check unit determines that at least one of the first sensor and the second sensor is malfunctioning.
Anti-rollover device. The dump vehicle is an autonomous vehicle that operates autonomously and raises and lowers the loading platform,
The check unit determines whether the first sensor and the second sensor have malfunctioned before the dump vehicle is operated.
The rollover prevention device according to claim 1 .