Tilt collision detection system, tilt drive mechanism

Abstract

To provide a gate collision sensing system that can sense collision of a gate during automatic opening and closing of the gate accurately and quickly, without needing a large-scale detecting system.SOLUTION: A gate collision sensing system is provided with: an acceleration sensor X1 provided in a bracket 1 of a gate driving mechanism Y that automatically opens and closes a gate A arranged on a loading platform T1 of a cargo vehicle T; a difference calculating part X2 that calculates a difference that is a degree of change of a calculated value based on a detected value by the acceleration sensor X1 during opening and closing of the gate A; and a determining part X3 that determines whether the gate A has collided with an obstacle, by comparing the difference with a predetermined difference threshold, which when the determining part X3 determines that the gate A has collided therewith, outputs a collision sensing signal showing the collision.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a system for detecting when an openable / closable gate provided on the bed of a cargo vehicle such as a truck comes into contact with or collides with an obstacle during opening / closing operation, and to a gate drive mechanism equipped with a gate collision detection system. [Background technology]

[0002] The transportation industry accounts for approximately 5% of Japan's GDP, and the logistics industry, which accounts for more than 60% of the transportation industry's market, is expanding due to environmental changes and is expected to continue to grow significantly in the future. Meanwhile, the logistics industry is seeking to automate truck loading and unloading operations in order to address the labor shortage of truck drivers and improve safety, and a tilt mechanism has been developed that automatically opens and closes the tilt (also called gate) installed on the loading platform using electricity (see, for example, Patent Document 1).

[0003] When automatically opening and closing the gate by electrification, the safety of the opening and closing operation of the gate, which is a heavy object, is important.

[0004] Various methods have been known for detecting contact with a moving body, and one example thereof is a method in which a load sensor is attached to the moving body, which is the object to be detected, to detect the contact load. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-182376 Summary of the Invention [Problem to be solved by the invention]

[0006] However, if load sensors are used to detect when the tilt-tilt has collided with an obstacle, the locations where the obstacle may come into contact with the large area of ​​the tilt-tilt are not limited, so it is necessary to install load sensors over a wide area, which results in a large and complex detection system and leads to high costs.

[0007] The present invention has been made in light of these problems, and its main object is to provide a tilt collision detection system that can accurately and quickly detect a tilt collision during automatic opening and closing without requiring a large-scale detection system, and a tilt drive mechanism equipped with such a collision detection system. [Means for solving the problem]

[0008] That is, the present invention relates to a gate collision detection system applicable to a gate drive mechanism that automatically opens and closes a gate provided on the bed of a cargo vehicle using the driving force of an actuator. Examples of cargo vehicles with beds include trucks, trailers, dump trucks, etc. A gate is also called a gate, and specific examples include a side gate that defines the side of the bed and a tailgate that defines the rear of the bed.

[0009] The tilt collision detection system according to the present invention comprises an acceleration sensor provided on a predetermined part of the tilt drive mechanism that moves in conjunction with the opening and closing movement of the tilt; a difference calculation unit that calculates a difference, which is the degree of change in either the detection value of the acceleration sensor or a calculated value based on the detection value, when the tilt is opened or closed; and a judgment unit that compares the difference calculated by the difference calculation unit with a predetermined difference threshold value to judge whether the tilt has collided with an obstacle, and is characterized in that when the judgment unit determines that the tilt has collided with an obstacle, it outputs a collision detection signal indicating the collision.

[0010] In the tilt collision detection system according to the present invention, when the tilt opens or closes, a difference calculation unit calculates the difference between the detection value of an acceleration sensor provided on a predetermined part of the tilt drive mechanism that moves with the opening or closing movement of the tilt or a calculated value based on the detection value, and a determination unit determines whether the tilt has collided with an obstacle by comparing the calculated difference with a preset difference threshold. Therefore, a tilt collision can be detected by monitoring the detection value of the acceleration sensor, eliminating the need to provide a detection system on the entire surface of the tilt. Furthermore, compared to an embodiment in which a detection system is provided on the entire surface of the tilt, a large-scale detection system is not required, achieving cost reductions and avoiding a situation in which a significant increase in weight is required to detect a tilt collision. In addition, the tilt-tilt collision detection system according to the present invention is configured to output a collision detection signal indicating that the tilt-tilt has collided with an obstacle when the determination unit determines that the tilt-tilt has collided with an obstacle, that is, when the detected angle difference exceeds the difference threshold (if the threshold has upper and lower limit values, when it exceeds the upper limit value or falls below the lower limit value), so that when the collision detection signal is output, post-collision processing can be quickly performed, such as temporarily halting the tilt-tilt opening / closing operation by the tilt-tilt drive mechanism or rotating the tilt-tilt in the direction opposite to the rotation direction at the time of collision detection.Furthermore, by not providing an acceleration sensor in the tilt-tilt itself, the width of the cargo vehicle can be kept within the regulated value, which has the advantage of not interfering with the cargo loading area (not reducing the volume).

[0011] Tilt collision detection system according to the present invention Now, further ,A total of two or more axial acceleration sensors are used as acceleration sensors. BecauseThis improves collision detection accuracy compared to when a single-axis acceleration sensor is used. In this case, if the two- or more-axis acceleration sensor detects acceleration at least in the short-side direction of the tilt, which coincides with the height direction of the tilt when it is in an upright position, and in the thickness direction of the tilt, the two- or more-axis acceleration sensor can also detect the tilt angle. In other words, a two- or more-axis acceleration sensor installed on a specific part of the tilt drive mechanism that moves with the opening and closing movement of the tilt functions as an inclination angle sensor that directly detects the tilt angle. The tilt angle can be calculated with extremely high accuracy using the detection value of the two-axis acceleration sensor, and tilt collision detection can be performed simultaneously while monitoring the tilt angle, thereby realizing a highly useful collision detection system.

[0012] The tilt collision detection system according to the present invention is equipped with the above-mentioned two- or more-axis acceleration sensor. Because ,moreover Tilt collision detection system The system is equipped with a tilt angle calculation unit that calculates the tilt angle based on the detection values ​​of two or more axis acceleration sensors, and the difference calculation unit calculates the angle difference (amount of change in angle) based on the tilt angle.If the system is configured so that the angle difference is compared with a difference threshold value to determine whether a tilt collision has occurred, the occurrence of a collision can be detected by monitoring the amount of change in the tilt rotation angle as the detection target.

[0013] Furthermore, a gate drive mechanism according to the present invention automatically opens and closes a gate provided on the bed of a freight vehicle by the driving force of an actuator, and is characterized by being equipped with the above-mentioned gate collision detection system. Such a gate drive mechanism provides the same various effects as the above-mentioned gate collision detection system, and can be easily introduced into work sites where automation of truck loading and unloading operations is desired. [Effects of the Invention]

[0014] According to the present invention, a collision of the tilt can be detected based on the detection value of an acceleration sensor provided on a specific part of the tilt drive mechanism that moves in conjunction with the opening and closing operation of the tilt. This eliminates the need to provide a detection system on the entire surface of the tilt, and makes it possible to provide a tilt collision detection system that does not require a large-scale detection system but can accurately and quickly detect a collision when the tilt is automatically opened or closed, and a tilt drive mechanism equipped with such a collision detection system. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an overall schematic diagram of a freight vehicle equipped with a tilt collision detection system according to an embodiment of the present invention; [Figure 2] FIG. 2 is a diagram showing a tilt drive mechanism according to the embodiment. [Figure 3] FIG. 2 is a diagram showing a tilt drive mechanism according to the embodiment. [Figure 4] 6A to 6C are diagrams showing a time series of automatic opening and closing processes of the tilt mechanism performed by the tilt drive mechanism according to the embodiment. [Figure 5] FIG. 2 is a configuration diagram of the tilt collision detection system according to the embodiment. [Figure 6] 10A and 10B are diagrams showing an example of detection by the acceleration sensor during automatic opening / closing processing of the tilt sensor in the embodiment. [Figure 7] 10 is a diagram showing an acceleration sensor detection graph (detection waveform) during automatic gate opening / closing processing in the embodiment. FIG. [Figure 8] 5A and 5B are diagrams showing the behavior of the tilt angle and the detected angle difference when a tilt collision occurs in the embodiment; [Figure 9] 10 is a flowchart of a tilt collision detection process in the embodiment. [Figure 10] 5 is a diagram showing a modified example of the tilt collision detection system according to the embodiment, corresponding to FIG. 4. [Figure 11] 10A and 10B are diagrams showing the behavior of the detected acceleration difference and the motor load factor, including during a tilt collision, according to the modified example. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0017] The tilt collision detection system X according to this embodiment is a system that can detect a collision of a tilt A of a loading platform T1 with an obstacle during opening / closing operation by being installed in, for example, a cargo vehicle T (truck) shown in FIG.

[0018] The truck T is a large truck (e.g., a 25-ton truck) equipped with a truck body T3 on which tires T2 are mounted and a loading platform T1 mounted on the truck body T3. Figures 1(a) and 1(b) are schematic side and rear views of the truck T, respectively.

[0019] The bed T1 of the truck T is rotatably attached via hinges T5 to an underframe T4 provided around the floor T6 of the cargo space, and is equipped with gates A (specifically, one pair of gates A on each side, a total of four gates A) that openably cover the lower left and right sides of the cargo space, and wings W that openably cover the space above the cargo space. In order to maintain the gates A in an upright, closed state (A1), pillars (not shown) are provided at the middle and end portions on the left and right sides of the underframe T4.

[0020] Various parts and mechanisms are disposed below the floor T6 of the luggage compartment and the underframe T4. Therefore, the free space below the floor T6 of the luggage compartment and the underframe T4 is quite narrow, and the tilt drive mechanism Y of this embodiment shown in Figures 2 and 3 is disposed in this narrow space. Here, Figure 2 schematically shows the tilt drive mechanism Y and peripheral devices (hardware) including a power supply that is the drive source for driving the tilt drive mechanism Y. Also, Figure 3 is a simplified schematic diagram that specifically shows the hardware around the tilt drive mechanism Y extracted from Figure 2.

[0021] In this embodiment, a number of gate drive mechanisms Y corresponding to the number of gates A to be arranged (four in this embodiment) are provided on the floor T6 of the luggage compartment and in the open space below the underframe T4, and each gate A can be automatically opened and closed individually by each gate drive mechanism Y. The gate drive mechanism Y makes it possible to automatically perform the opening and closing work of the gates A, which can be a great burden for an operator, and even if the driver of the truck T is an elderly person, a woman, or someone with little strength, the opening and closing work of the gates A can be easily performed.

[0022] 2 and 3, the tilt drive mechanism Y includes a bracket 1 that supports the tilt A. The bracket 1 is fixed to the tilt A at a position higher than the tilt rotation axis (hinge T5) of the tilt A when the tilt A is in the closed state (A1), and rotates integrally with the tilt A around the tilt rotation axis T5 when the tilt A opens or closes. 3, the tilt drive mechanism Y includes a first arm 2 whose tip (upper end) is pivotally connected to a bracket 1, a second arm 4 whose tip (upper end) is pivotally connected to a base end (lower end) of the first arm 2 in the space below an underframe T4 provided around the floor of the luggage compartment and whose base end (lower end) is fixed by a first fixed shaft 3, an actuator 5 disposed in a recumbent position (sideways position) in the space below the underframe T4, a third arm 7 whose one end is pivotally connected to the tip of the actuator 5 and which swings about a second fixed shaft 6 in accordance with the forward and backward movement of the actuator 5, and a connecting arm 8 connecting the third arm 7 and the second arm 4. The tilt drive mechanism Y includes a link mechanism L made up of such multiple arms, and the tilt A can be automatically opened and closed by operating the link mechanism L with the actuator 5.

[0023] The actuator 5 includes a rod that can be advanced and retracted by the torque of a drive motor (e.g., a DC motor) shown in FIG. 2, and the tip of the rod is pivotally attached to a suitable location on the third arm 7. Note that a motor other than a DC motor, such as an AC motor or a servo motor, can also be used as the drive motor. The third arm 7 swings about the second fixed shaft 6 as the rod advances and retracts. The second arm 4, which is connected to the third arm 7 via a connecting arm 8, rotates about the first fixed shaft 3 as the third arm 7 swings. Therefore, when the tilt A is in the closed state (A1), which is an upright position at +90 degrees as shown in FIGS. 2 and 3, driving the actuator 5 to move the rod forward in the positive direction causes the third arm 7, connecting arm 8, and second arm 4 to move in unison. As the second arm 4 rotates, the first arm 2 moves downward while remaining in the upright position, gradually changing the tilt A from the closed state (A1) to the open state (A2), which is an upright position at -90 degrees. FIG. 4 shows a schematic diagram of the process by which the angle of the tilt A changes in accordance with the movement of the tilt drive mechanism Y, from +90 degrees (closed state, FIG. 4(a)), +45 degrees (FIG. 4(b)), 0 degrees (horizontal state, FIG. 4(c)), -45 degrees (FIG. 4(d)), to -90 degrees (open state, FIG. 4(e)). The bracket 1 moves while rotating around the rotation axis 1a (hinge) that connects it to the first arm 2, in unison with the opening and closing movement of the tilt A. The actuator 5 can be, for example, one that has a structure in which a motor operated by a voltage of 24 volts moves a rod back and forth, and which also has a load holding mechanism that can hold the load applied to the rod even when the motor rotation is stopped.

[0024] The tilt drive mechanism Y automatically opens and closes the tilt A using the driving force of a motor. Specifically, when a higher-level controller (control unit C) receives a drive command (such as "Open tilt A" or "Close tilt A," which is equivalent to the open / close command shown in FIG. 2) based on an operator (such as a truck driver) operating an input device such as an appropriate button, switch, or touch panel, the control unit C generates an angle command to set the tilt A at the desired angle, performs position control using this angle command and the actual tilt angle, and generates a speed command that determines how to move the motor (the distance the actuator 5 should move forward or backward). Next, the control unit C controls the motor speed by adjusting it relative to the speed command, generates a current command, and performs current control using the current command and the motor current (the current actually input to the motor) to drive the motor. As a result, the rod of the tilt drive mechanism Y moves forward or backward using the driving force of the motor, automatically opening and closing the tilt A. As shown in FIG. 2, an auxiliary power spring mechanism 51 for applying auxiliary power to the periphery of the actuator 5 and a tilt drive mechanism Y in which a speed-up gear unit G is disposed may be configured.

[0025] The tilt drive mechanism Y according to this embodiment is equipped with a tilt collision detection system X that detects when the tilt A collides with an obstacle during automatic opening / closing operation.

[0026] As shown in FIG. 5, the tilt collision detection system X includes an acceleration sensor X1 mounted on a bracket 1 of the tilt drive mechanism Y that moves with the opening and closing movement of the tilt A, a difference calculation unit X2 that calculates a difference, which is the degree of change in a calculated value based on the detection value of the acceleration sensor X1, when the tilt A opens or closes, and a determination unit X3 that compares the difference calculated by the difference calculation unit X2 with a preset difference threshold value to determine whether the tilt A has collided with an obstacle, and outputs a collision detection signal indicating the collision when the determination unit X3 determines that the tilt A has collided with an obstacle.

[0027] In this embodiment, a two-axis acceleration sensor is used as the acceleration sensor X1 (hereinafter simply referred to as the "acceleration sensor"). The acceleration sensor X1 detects acceleration in the short-side direction of the tilt A (Z-axis in FIG. 6) and the thickness direction of the tilt A (X-axis in FIG. 5). The short-side direction of the tilt A in the closed state (A1) coincides or substantially coincides with the direction of gravity, and the thickness direction of the tilt A in the closed state (A1) coincides or substantially coincides with one or more components of the horizontal direction. The tilt collision detection system X of this embodiment is configured to attach such an acceleration sensor X1 to a bracket 1 of the tilt drive mechanism Y and detect the angle of the tilt A. In other words, the detection value of the acceleration sensor X1 attached to the tilt A changes with changes in the open / closed state of the tilt A, so it is possible to detect the angle of the tilt A from the acceleration of gravity. In light of this, the tilt collision detection system X of this embodiment includes a tilt angle calculation unit X4 that calculates the angle of the tilt A based on the detection value of the acceleration sensor X1. The acceleration sensor X1 is electrically connected to the tilt drive mechanism Y by a connecting wire.

[0028] 6, the acceleration sensor X1 can detect the gravitational acceleration as an acceleration component on each axis (X-axis, Z-axis) according to the tilt angle of the tilt A. In other words, if the angle of the tilt A is θ, the horizontal angle of the tilt A (horizontal state) is 0 deg, the closed state of the tilt A (closed state A1) is +90 deg, and the open state of the tilt A (open state A2) is -90 deg, then X-axis detected value = Gravitational acceleration (1G detected value) × cos(θ) Z-axis detected value = gravitational acceleration (1G detected value) × sin(θ) Tilt angle θ = arctan (Z-axis detection value / X-axis detection value) This results in a detection waveform as shown in Fig. 7. Based on this, the tilt angle calculation unit X4 calculates the angle of tilt A based on the detection value of the acceleration sensor X1.

[0029] The difference calculation unit X2 calculates a difference based on the angle of the tilt A calculated by the tilt angle calculation unit X4. Specifically, the difference calculation unit X2 calculates the angle difference of the tilt A (Dlta = current calculated value of the tilt angle - previous calculated value of the tilt angle).

[0030] The judgment unit X3 compares the difference (angle difference of tilt A, hereinafter referred to as "detected angle difference") calculated by the difference calculation unit X2 with a difference threshold value stored in advance in a predetermined memory unit X5, and judges that tilt A has collided with an obstacle if the difference exceeds the difference threshold value, and judges that tilt A has not collided with an obstacle if the difference does not exceed the difference threshold value.

[0031] Here, the impact vibrations generated when the tilt A collides with an obstacle during opening / closing operation appear as detected values ​​by the acceleration sensor X1. As shown in FIG. 8, a plot of the angle of the tilt A when it collides with the obstacle (a value calculated by the tilt angle calculation unit X4) and the detected angle difference (a difference calculated by the difference calculation unit X2) indicates that the detected angle difference exceeded a preset difference threshold immediately after the actual timing when the tilt A collides with the obstacle. The tilt collision detection system X of this embodiment is configured to determine whether the tilt A has collided with an obstacle by monitoring the fluctuation in the tilt angle (detected angle difference) based on the detected value of the acceleration sensor X1, taking into consideration the relationship between the behavior of the tilt operation of the tilt A at the time of a tilt collision and the angle difference of the tilt A (detected angle difference). In the figure, the value calculated by the tilt angle calculation unit X4 is not converted into an absolute value, but the detected angle difference is determined to be greater than a difference threshold having a predetermined numerical range (the range from the lower collision change limit to the upper collision change limit), i.e., more specifically, whether the detected angle difference is greater than the upper collision change limit and whether the detected angle difference is smaller than the lower collision change limit. Note that the determination unit X3 may be configured to compare the absolute value of the detected angle difference with a certain difference threshold, and determine that tilt A has collided if the absolute value of the detected angle difference exceeds the difference threshold.

[0032] The control unit C controls the entire tilt collision detection system X according to this embodiment. When the determination unit X3 determines that the tilt A has collided with an obstacle (when a collision is detected), the control unit C controls the system to output a collision detection signal indicating the collision. Based on the collision detection signal, the control unit C performs processes such as stopping the opening / closing operation of the tilt A, rotating the tilt A in the opposite direction to when the collision was detected, issuing a warning sound, and displaying a warning on a monitor in the cab, thereby enabling prompt response after the collision. The control unit C may be a control unit (host controller) higher than the tilt collision detection system X and the tilt drive mechanism Y, or may be a control unit dedicated to the tilt collision detection system X. The control unit C is composed of a normal microprocessor or the like equipped with a CPU, memory, and interface. The memory stores programs required for processing, and the CPU sequentially retrieves and executes the necessary programs to achieve the desired functions in cooperation with peripheral hardware resources.

[0033] The procedure for detecting a tilt collision by the tilt collision detection system X according to this embodiment having the above configuration is as follows.

[0034] First, when the control unit C receives an operation input from the operator, it drives the tilt drive mechanism Y based on a drive command corresponding to the received input information (such as a command to "open the tilt A" or "close the tilt A") to switch the tilt A from the closed state (A1) to the open state (A2) or from the open state (A2) to the closed state (A1). During this automatic tilt opening / closing process, the tilt collision detection system X detects acceleration using the acceleration sensor X1 (acceleration detection step S1, see FIG. 8), and calculates a difference using the difference calculation unit X2 based on the detected acceleration (X-axis data, Z-axis data) (difference calculation step S2).

[0035] In this embodiment, in difference calculation step S2, or as preprocessing for difference calculation step S2, a process (tilt angle calculation step S21) is executed in which the tilt angle calculation unit X4 calculates the angle of tilt A based on the data detected in acceleration detection step S1, and a difference (detected angle difference) is calculated based on the calculated angle of tilt A. Following difference calculation step S2, the control unit C executes a process (determination step S3) in which the determination unit X3 compares the difference with a difference threshold to determine whether or not tilt A has collided with an obstacle. If it is determined in determination step S3 that tilt A has collided with an obstacle, a collision detection signal indicating the collision is output (collision detection signal output step S4). Note that if it is not determined in determination step S3 that tilt A has collided with an obstacle, and the opening / closing operation of tilt A is still ongoing, the process returns to acceleration detection step S1, and the above-described process is repeated.

[0036] After the above processing, if the control unit C outputs a collision detection signal indicating a collision has occurred, it executes appropriate post-collision processing (such as stopping the motor, moving the tilt A in the direction opposite to the rotation direction at the time of collision detection, emitting a warning sound, and displaying a warning on a monitor in the cab). Note that the opening and closing operation of the tilt A by the tilt drive mechanism Y is not limited to switching the tilt A from the closed state (A1) to the open state (A2) or from the open state (A2) to the closed state (A1), but also includes switching from the closed state (A1) or the open state (A2) to an arbitrary tilt angle (any angle in the range of -89 degrees to +89 degrees), switching from any tilt angle to the closed state (A1) or the open state (A2), and switching between arbitrary tilt angles.

[0037] As described above, the tilt collision detection system X according to this embodiment is configured to directly detect the tilt angle using the acceleration sensor X1 provided on the bracket 1 of the tilt drive mechanism Y, which moves with the opening and closing movement of the tilt A. The system determines whether a detected angle difference, which is the degree of change in a calculated value based on the detection value of the acceleration sensor X1, exceeds a difference threshold. If the detected angle difference exceeds the difference threshold, the system outputs a collision detection signal indicating that the tilt A has collided with an obstacle. Therefore, by monitoring the detection value of the acceleration sensor X1, which detects the rotation angle of the tilt A, a collision of the tilt A can be detected. This eliminates the need for a detection system on the entire surface of the tilt A, making it extremely cost-effective compared to a system in which a detection system is provided on the entire surface of the tilt A. In addition, the tilt collision detection system X according to this embodiment uses the acceleration sensor X1 as an inclination angle sensor that detects the tilt angle and is configured to also detect a collision of the tilt A using the detection value of the tilt angle detection sensor. Therefore, a dedicated sensor specialized only for collision detection is not required, and no additional detection system other than the acceleration sensor X1 is required. This avoids a complex structure and suppresses an increase in weight.

[0038] Furthermore, the tilt collision detection system X according to this embodiment can detect a collision faster than a method of detecting a collision of the tilt A based on the motor load rate. This will be described later. By being able to detect a collision faster, post-collision processing can also be performed more quickly.

[0039] In particular, according to the tilt collision detection system X of this embodiment, the acceleration sensor X1 is provided on the bracket 1 of the tilt drive mechanism Y that is directly attached to the tilt A, so that the angle of the tilt A is directly measured by the detection value of the acceleration sensor X1, which can eliminate a problem that can occur when the tilt angle is detected indirectly rather than directly, that is, a problem that the S / N ratio deteriorates depending on the angle of the tilt A and the detection accuracy deteriorates, and the angle of the tilt A can be calculated with extremely high accuracy. The tilt collision detection system X of this embodiment, which can simultaneously perform tilt collision detection while monitoring the angle of the tilt A, is extremely useful and practical.

[0040] Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations of the above-described embodiments. For example, in the above-described embodiments, a difference (change in the tilt rotation angle, detected angle difference) is calculated, which is a calculated value based on the detection value of the acceleration sensor X1, indicating the degree of change in the angle of the tilt A, and the calculated difference is compared with a difference threshold to detect a collision of the tilt A. However, a configuration is also possible in which the difference calculation unit X2 calculates the difference (X-axis acceleration difference or Z-axis acceleration difference) between at least one or both of the detected X-axis acceleration value (X-axis data) and the detected Z-axis acceleration value (Z-axis data), which are the detection values ​​of the acceleration sensor X1. FIG. 10 shows, corresponding to FIG. 5, a configuration in which the difference calculation unit X2 calculates the X-axis acceleration difference, and the determination unit X3 compares the calculated X-axis acceleration difference with a difference threshold to determine whether the tilt A has collided. In FIG. 10, a collision change upper limit value is set as the difference threshold, the calculated X-axis acceleration difference is converted into an absolute value, and when the absolute acceleration difference exceeds the collision change upper limit value, the determination unit X3 determines that the tilt A has collided and outputs a collision detection signal.

[0041] FIG. 11 shows data demonstrating that the tilt collision detection system X according to the present invention can detect a collision more quickly than a configuration that detects a collision of the tilt A based on the motor load factor. The data is collision detection data when the configuration shown in FIG. 10 is adopted (the difference calculation unit X2 calculates the X-axis acceleration difference, and the determination unit X3 compares the calculated X-axis acceleration difference with a difference threshold to determine whether the tilt A has collided). FIG. 11 shows data plotting the difference (amount of change) in the previous value of the X-axis acceleration of the acceleration sensor X1 and the change in the load factor of the motor amplifier at the time of a collision. While the data is based on a setting that determines that the tilt A has collided when the motor load factor exceeds 30%, the configuration that detects the collision of the tilt A based on the motor load factor detects the collision of the tilt A with a delay of about 1.5 seconds from the time of the collision. Meanwhile, the tilt collision detection system X according to the present invention can detect the collision simultaneously or approximately simultaneously (within 0.1 seconds) with the time of the collision.

[0042] Furthermore, the tilt collision detection system of the present invention may be equipped with a three- or more-axis acceleration sensor, or may be equipped with a one-axis acceleration sensor.

[0043] The present invention also includes a configuration in which the acceleration sensor is provided on a part of the tilt drive mechanism other than the bracket.

[0044] A specific example of the tilt drive mechanism is not limited to the above-mentioned tilt drive mechanism Y, and the tilt collision detection system of the present invention can be applied to any mechanism that automatically opens and closes the tilt using the driving force of an actuator. The tilt collision detection system may be a system included in the tilt drive mechanism, or may be a system that is mechanically or electrically separated from the tilt drive mechanism.

[0045] The cargo vehicles in which the tilt collision detection system of the present invention alone or a tilt drive equipped with the tilt collision detection system can be implemented are not limited to trucks (small trucks (2-ton and 3-ton trucks), medium trucks (4-ton trucks), large trucks (10-ton trucks), and light trucks, which are classified according to the load capacity), but can also be implemented in cargo vehicles T such as trailers and dump trucks.

[0046] In the above-described embodiment, the side gate (lateral gate) that defines the side of the loading platform is used as an example of the gate, but it is also possible to perform collision detection when the rear gate that defines the rear of the loading platform is opened or closed. The gate is also called a gate (side gate, back gate).

[0047] Furthermore, the specific configuration of each part is not limited to the above embodiment, and various modifications are possible within the scope of the present invention. [Explanation of symbols]

[0048] A…Tilt T... freight vehicle (truck) T1...cargo bed X...Tilt collision detection system X1...Acceleration sensor (2-axis acceleration sensor) X2...Difference calculation section X3...judgment section X4: Tilt angle calculation section Y...Tilt drive mechanism

Claims

1. A gate collision detection system applicable to a gate drive mechanism that automatically opens and closes a gate provided on the bed of a freight vehicle using an actuator, an acceleration sensor provided on a predetermined part of the tilt drive mechanism that moves in accordance with the opening and closing operation of the tilt; a difference calculation unit that calculates a difference, which is a degree of change in either the detected value of the acceleration sensor or a calculated value based on the detected value, during opening and closing of the tilt; a determination unit that compares the difference with a predetermined difference threshold value to determine whether the tilt has collided with an obstacle, The acceleration sensor is a two-axis or more acceleration sensor that detects acceleration in at least a short-side direction of the tilt that coincides with a height direction of the tilt in an upright posture and an acceleration in a plate thickness direction of the tilt, A tilt collision detection system, characterized in that when the determination unit determines that the tilt has collided with an obstacle, it outputs a collision detection signal indicating the collision.

2. a tilt angle calculation unit that calculates the tilt angle based on the detection value of the two or more axis acceleration sensor; the difference calculation unit calculates an angle difference, which is the difference, based on the tilt angle, The tilt collision detection system according to claim 1 , wherein the determination unit compares the angle difference with a difference threshold value to determine the tilt collision.

3. A gate drive mechanism that automatically opens and closes a gate provided on a cargo vehicle bed by an actuator, A tilt drive mechanism comprising the tilt collision detection system according to claim 1 or 2.

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