Forklift and control method thereof

Abstract

The present invention relates to a stacker and a control method thereof. The stacker includes a vehicle body, a mast member, a cargo-carrying member, a distance sensor and a processor. The mast member has a bottom end and a top end. The bottom end is fixed to the vehicle body, and the top end is opposite to the bottom end. The cargo-carrying member has a lifting part and a cargo-carrying part. The lifting part is movably arranged on the mast member, and the cargo-carrying part is connected to the lifting part and extends along an extension direction. The distance sensor is arranged on the lifting part and is located between the cargo-carrying part and the bottom end. The distance sensor is used to sense the distance of an object in the extension direction of the cargo-carrying part. The processor is electrically connected to the distance sensor and is used to determine whether the distance is less than a warning range. The present invention also provides a control method for a stacker. The present invention can prevent collisions caused by human judgment errors, and can prevent collisions with objects in front when the stacker moves forward.

Description

Technical Field

[0001] The present invention relates to a transport device, in particular to a forklift and a control method for the forklift. Background Art

[0002] Forklifts can carry and stack heavy goods, so they have been widely used in storage systems. However, due to the heavy weight of the forklift itself, the impact force of its collision is also large. If it hits the shelf or goods due to careless operation, it may cause property losses such as shelf collapse and damage to goods, or even cause casualties to nearby people.

[0003] To prevent the above accidents, conventional stackers are equipped with cameras at the front end, and operators can judge the distance between the stacker and the shelf through the images captured by the camera. However, when the stacker is very close to the shelf, the camera cannot provide a clear image due to insufficient light, which affects the operator's judgment. In addition, human judgment itself is prone to errors, so conventional stackers still cannot effectively prevent collisions.

[0004] This background technology section is only used to help understand the content of the present invention. Therefore, the content disclosed in the background technology may contain some known technologies that do not constitute known technologies known to ordinary technicians in the relevant technical field. In addition, the content disclosed in the background technology does not represent the problems to be solved by the content or one or more embodiments of the present invention, nor does it mean that it has been known or recognized by ordinary technicians in the relevant technical field before the application of the present invention. Summary of the invention

[0005] The invention provides a forklift, which can accurately detect the distance between the forklift and a front object when the forklift moves forward.

[0006] The invention provides a control method for a forklift to prevent the forklift from colliding with an object in front when the forklift moves forward.

[0007] Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

[0008] In order to achieve one or part or all of the above purposes or other purposes, the forklift provided by the present invention includes a vehicle body, a mast member, a cargo member, a distance sensor and a processor. The mast member has a bottom end and a top end. The bottom end is fixed to the vehicle body, and the top end is opposite to the bottom end. The cargo member has a lifting part and a cargo part. The lifting part is movably arranged on the mast member, and the cargo part is connected to the lifting part and extends along the extension direction. The distance sensor is arranged on the lifting part and is located between the cargo part and the bottom end. The distance sensor is used to sense the distance of an object in the extension direction of the cargo part. The processor is electrically connected to the distance sensor and is used to determine whether the distance is less than the warning range.

[0009] In order to achieve one or part or all of the above purposes or other purposes, the control method for a forklift provided by the present invention can prevent the forklift from colliding. The forklift includes the above features, and the control method includes the following steps. The distance of the object in the extension direction of the cargo part is sensed by a distance sensor. The lifting part is controlled to move to a predetermined position along the mast member by a processor. The processor determines whether the distance is less than the warning range. When the distance is greater than or equal to the warning range, the vehicle body is controlled to move toward the target object. When the distance is less than the warning range, the vehicle body is controlled to stop moving.

[0010] The forklift of the present invention adopts a distance sensor, and the distance sensor is arranged on the lifting part of the forklift. Before the forklift is ready to start picking up or unloading goods from the shelf, the lifting part will first move along the mast member to the height of the corresponding shelf layer, so that the distance sensor located on the lifting part will also move to the height of the corresponding shelf layer. In this way, when the forklift moves forward, the distance sensor can detect the distance between itself and the object in front (such as the shelf), thereby preventing collisions caused by human judgment errors. On the other hand, the control method for the forklift of the present invention can control the body of the forklift to stop moving when the aforementioned distance is less than the warning range, so that it can prevent collisions with objects in front when the forklift moves forward.

[0011] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 FIG. 4 is a schematic diagram of a forklift moving toward a target object according to an embodiment of the present invention.

[0013] Figure 2 yes Figure 1 Block diagram of a forklift.

[0014] Figure 3 FIG. 4 is a schematic diagram of a forklift moving toward a target object according to another embodiment of the present invention.

[0015] Figure 4 yes Figure 3 Schematic diagram of the arrangement of sensing elements of a forklift.

[0016] Figure 5 FIG. 4 is a schematic diagram of the arrangement of sensing elements of a forklift according to another embodiment of the present invention.

[0017] Figure 6 FIG. 4 is a schematic diagram of a forklift moving toward a target object according to another embodiment of the present invention.

[0018] Figure 7The figure is a flow chart of a control method for a forklift according to an embodiment of the present invention.

[0019] Figure 8 The figure is a flow chart of a control method for a forklift according to another embodiment of the present invention. DETAILED DESCRIPTION

[0020] The above and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only referenced to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and not to limit the present invention.

[0021] Figure 1 FIG. 4 is a schematic diagram of a forklift moving toward a target object according to an embodiment of the present invention. Figure 2 yes Figure 1 Please refer to the block diagram of the forklift. Figure 1 and Figure 2 The forklift 100 includes a vehicle body 110, a mast member 120, a cargo member 130, a distance sensor 140, and a processor 150. The mast member 120 has a bottom end B and a top end T. The bottom end B is fixed to the vehicle body 110, and the top end T is opposite to the bottom end B. The cargo member 130 has a lifting part 131 and a cargo member 132. The lifting part 131 is movably disposed on the mast member 120, and the cargo member 132 is connected to the lifting part 131 and extends along an extension direction E. The distance sensor 140 is disposed on the lifting part 131 and is located between the cargo member 132 and the bottom end B. The distance sensor 140 is disposed toward the extension direction E and can sense the distance D of an object O on the extension direction E of the cargo member 132, and the object O here is, for example, a shelf of a shelf or an obstacle on the path. The processor 150 is electrically connected to the distance sensor 140 and can determine whether the distance D is less than the warning range.

[0022] Please continue to refer to Figure 1 , the cargo carrying member 130 can move along the mast member 120 to a height suitable for picking up or unloading cargo. The cargo carrying portion 132 of the present embodiment is, for example, a fork. Specifically, the cargo carrying member 130 may have two opposite ends E1 and E2, the end E1 is connected to the lifting portion 131, and the extension direction E is, for example, from the end E1 to the end E2. Furthermore, the extension direction E is, for example, substantially parallel to the forward direction of the vehicle body 110 when it moves toward the object O, but the present invention is not limited thereto.

[0023] The distance sensor 140 of the present embodiment may be an optical distance sensor element to improve the detection accuracy through the high directivity feature. The optical distance sensor element includes, for example, a laser distance sensor, an infrared distance sensor, a photoelectric sensor using an LED as a light source, or other distance sensors including optical elements, but the present embodiment is not limited thereto. To further improve the detection accuracy, the distance sensor 140 of the present invention may include multiple sensing elements. For example, please refer to Figure 3 and Figure 4 In the forklift 100a, the distance sensor 140a may include sensing elements 141a, 142a and 143a, which are arranged on the lifting part 131 to provide a larger detection range. For example, the sensing elements 142a and 143a may be closer to the bottom end B of the mast member 120 than the sensing element 141a, so that the sensing element 141a can detect the distance D between the object O (such as the shelf board), and the sensing elements 142a and 143a can detect the distance D1 between the object O1 (such as the pallet or cargo), wherein the height of the object O1 on the shelf may be different from the height of the object O on the shelf. It is understood that the arrangement of the sensing elements 141a, 142a and 143a is not limited to that shown in the drawings. For example, Figure 3 and Figure 4 The sensing elements 141a, 142a and 143a can be arranged in the Y direction to detect objects O and O1 at different heights. Figure 5 For the forklift 100b, the sensing elements 141b of the distance sensor 140b can be arranged in the Z direction to provide different Figure 4 In another embodiment, the sensing elements 141a, 142a and 143a (or the sensing element 141b) may also be arranged in a matrix or other planar shapes, and the specific arrangement may be determined according to actual needs, and the present invention does not impose any further restrictions on this.

[0024] Similar to Figure 3 An embodiment of Figure 6 The distance sensor 140c of the forklift 100c may include sensing elements 141c, 142c and 143c, and the sensing elements 141c, 142c and 143c may have the function of sending and receiving signals. In detail, the angle at which the sensing element 141c sends the signal G1 is different from the angle at which the sensing elements 142c and 143c send the signals G2 and G3, so as to further expand the detection range. For example, the sensing elements 142c and 143c may send signals G2 and G3 along the extension direction E to detect the distance D between the object O (such as the shelf), and the sensing element 141c may send a signal G1 toward the ground to detect the distance D2 between the object O2 (such as debris on the ground). By the way, Figure 6The arrangement direction of the sensing elements 141c, 142c and 143c is only for illustration and is not intended to limit the present embodiment. In addition, the number of the sensing elements 141a, 142a, 143a, 141b, 141c, 142c and 143c in each embodiment can be changed according to actual needs, and the present invention does not impose any restrictions on this.

[0025] Please refer to Figure 1 and Figure 2 The processor 150 of this embodiment may include a microcontroller unit (MCU), but the present invention is not limited thereto. The processor 150 may control the operation of the cargo carrier 130, the distance sensor 140 and other components, and the detailed features will be described below.

[0026] The vehicle body 110 can be moved by human control or by the processor 150 control, such as automatic driving, wherein the vehicle body 110 of the present embodiment is, for example, moved by the processor 150 control, but other embodiments are not limited thereto. In detail, the stacker 100 of the present embodiment may further include a wheel drive element 160. The wheel drive element 160 is disposed in the vehicle body 110 and is electrically connected to the processor 150. The processor 150 can control the wheel drive element 160 to drive the vehicle body 110 to move, and the processor 150 can control the wheel drive element 160 to stop moving the vehicle body 110 when the distance D is less than the warning range, so as to further prevent the stacker 100 from colliding with the object O. In the present embodiment, the wheel drive element 160, for example, includes a wheel drive motor, but the present invention is not limited thereto.

[0027] The stacker 100 of this embodiment may further include a positioning device 170. The positioning device 170 is disposed at the top T of the mast member 120 and can locate the coordinate position of the stacker 100. The processor 150 calculates the target distance TD between the stacker 100 and the target object TO by means of the above-mentioned coordinate position. In detail, the above-mentioned coordinate position is, for example, the position of the stacker 100 in the storage environment, and will change as the stacker 100 moves. The target object TO is, for example, a shelf where the stacker 100 is preset to pick up or unload goods, and the processor 150 can control the vehicle body 110 to move toward the target object TO by means of the above-mentioned coordinate position so as to perform actions such as picking up or unloading goods. In this embodiment, the positioning device 170 may include a two-dimensional or three-dimensional optical radar (LiDAR). In another embodiment, the positioning device 170 may include an inertial measurement unit (IMU), but the present invention is not limited thereto.

[0028] Compared with the prior art, the stacker 100 of the present embodiment adopts a distance sensor 140, and the distance sensor 140 is disposed on the lifting part 131 of the stacker 100. Before the stacker 100 is ready to start picking up or unloading goods from the shelf, the lifting part 131 will first move along the mast 120 to the height of the corresponding shelf layer, so that the distance sensor 140 located on the lifting part 131 will also move to the height of the corresponding shelf layer. In this way, when the stacker 100 moves forward, the distance sensor 140 can detect the distance D between itself and the object O in front (such as the shelf layer), thereby preventing collisions caused by human judgment errors.

[0029] Figure 7 This is a flow chart of a control method for a forklift according to an embodiment of the present invention. Figure 1 , Figure 2 and Figure 7 , the control method for a stacker of this embodiment can prevent the stacker 100 from colliding. The stacker 100 includes the above-mentioned features, and the control method for the stacker includes the following steps. Please refer to step S1: sense the distance D of the object O in the extension direction E of the cargo carrying part 132 through the distance sensor 140. The extension direction E is, for example, substantially parallel to the forward direction of the vehicle body 110 when moving toward the object O, but is not limited thereto.

[0030] Next, please refer to step S2: the processor 150 controls the lifting unit 131 to move to a predetermined position along the mast 120; wherein the predetermined position may correspond to the height of the pallet to be picked up (or unloaded). Incidentally, the distance sensor 140 of this embodiment can continue to operate when the lifting unit 131 moves along the mast 120, but the present invention is not limited thereto.

[0031] After the lifting part 131 moves to the predetermined position along the mast 120, step S3 is performed: the processor 150 determines whether the distance D is less than the warning range. The warning range may be determined according to the weight of the forklift 100 and the cargo, for example, between several centimeters and tens of centimeters, but the present invention is not limited thereto.

[0032] Please refer to step S4, when the distance D is greater than or equal to the warning range, the vehicle body 110 is controlled to move toward the target object TO. In other words, when the distance D is greater than or equal to the warning range, the processor 150 determines that the vehicle body 110 has no risk of collision, and thus controls the vehicle body 110 to continue to move toward the target object TO.

[0033] Please refer to step S5. When the distance D is less than the warning range, the vehicle body 110 is controlled to stop moving to prevent the forklift 100 from colliding with the object O. For example, the wheel drive element 160 can be controlled by the processor 150 to stop moving the vehicle body 110. The wheel drive element 160 may include a wheel drive motor, but other embodiments are not limited to this. Incidentally, when the distance D is less than the warning range, the cargo portion 132 of the cargo carrier 130 has extended above the shelf, so the cargo carrier 130 can start to perform actions such as picking up or unloading, but the present invention does not impose more restrictions on specific subsequent operations. In addition, the cargo carrier 130 can be controlled by the processor 150, but the present invention is not limited to this.

[0034] Figure 8 is a flow chart of a control method for a stacker according to another embodiment of the present invention. Figure 1 , Figure 2 and Figure 8 , after step S5, the control method for a forklift may further include step S6: turning off the distance sensor 140 through the processor 150. In detail, when the distance sensor 140 is very close to the target object TO, it is easy to detect some debris that will not cause a collision accident, such as dust or wires, or the wires of the goods are regarded as obstacles. Therefore, after determining that the distance D is less than the warning range, the processor 150 may turn off the distance sensor 140 to prevent the vehicle body 110 from stopping moving due to the misdetection of the above-mentioned debris. Incidentally, the processor 150 may start to control the cargo carrier 130 to perform the action of picking up or unloading after turning off the distance sensor 140, and control the vehicle body 110 to leave the target object TO after the cargo carrier 130 completes picking up or unloading.

[0035] Before performing step S1, the control method for a stacker may further include step S0: positioning the coordinate position of the stacker 100 by the positioning device 170. The detailed features of the positioning device 170 and the above-mentioned coordinate position have been described above, so the relevant description is omitted here.

[0036] After locating the coordinate position of the stacker 100, the control method for the stacker may further include step S7: calculating the target distance TD between the stacker 100 and the target object TO by the processor 150 based on the coordinate position. In detail, the target object TO may be a shelf to be picked up or unloaded, and the processor 150 can determine whether the stacker 100 has arrived in front of the target object TO based on the target distance TD. Before the stacker 100 arrives in front of the target object TO, the processor 150 can turn off the distance sensor 140 to prevent the distance sensor 140 from stopping moving due to misdetection of other objects before the stacker 100 approaches the target object TO. In addition, when the storage environment of the positioning device 170 changes significantly (for example, changing the positions of multiple shelves), it may be impossible to accurately locate the coordinate position of the stacker 100. In this case, the processor 150 can turn on the distance sensor 140 and determine whether the distance D is less than the warning range to prevent the stacker 100 from colliding during the process of moving toward the target object TO.

[0037] After step S7, the control method for a stacker may further include step S8: determining, by the processor 150, whether the target distance TD is less than or equal to the warning range. When the target distance TD is less than or equal to the warning range, the above step S5 may be performed first, and then the above step S6 may be performed. When the target distance TD is greater than the warning range, the above step S4 may be performed. Incidentally, steps S7 and S8 of this embodiment may be performed simultaneously with steps S1, S2, and S3. For example, when the distance sensor 140 detects and determines whether the distance D is less than the warning range, the positioning device 170 may simultaneously detect and determine whether the target distance TD is less than or equal to the warning range, but other embodiments are not limited thereto.

[0038] Compared with the prior art, since the control method for a stacker in this embodiment can control the vehicle body 110 to stop moving when the distance D between the stacker 100 and the object O is less than the warning range, it can prevent the stacker 100 from colliding with the object O in front when it moves forward. In addition, the control method for a stacker in this embodiment can also be applied to stackers 100a, 100b and 100c.

[0039] In summary, the forklift of the present invention adopts a distance sensor, and the distance sensor is arranged on the lifting part of the forklift. Before the forklift is ready to start picking up or unloading goods from the shelf, the lifting part will first move along the mast member to the height of the corresponding shelf layer, so that the distance sensor located on the lifting part will also move to the height of the corresponding shelf layer. In this way, when the forklift moves forward, the distance sensor can detect the distance between itself and the object in front (such as the shelf), thereby preventing collisions caused by human judgment errors. On the other hand, the control method for the forklift of the present invention can control the body of the forklift to stop moving when the aforementioned distance is less than the warning range, so that it can prevent collisions with objects in front when the forklift moves forward.

[0040] The above is only the preferred embodiment of the present invention, and it cannot be used to limit the scope of the implementation of the present invention. That is, all simple equivalent changes and modifications made according to the claims and the specification of the present invention are still within the scope of the patent of the present invention. In addition, any embodiment or claim of the present invention does not need to achieve all the purposes, advantages or features disclosed in the present invention. In addition, the abstract and the invention name are only used to assist the search of patent documents, and are not used to limit the scope of rights of the present invention.

[0041] 100, 100a, 100b, 100c: Forklift

[0042] 110: Car body

[0043] 120:Mast

[0044] 130: Cargo

[0045] 131: Lifting Department

[0046] 132: Cargo Department

[0047] 140, 140a, 140b, 140c: distance sensors

[0048] 141a, 141b, 141c, 142a, 143a, 142c, 143c: sensing elements

[0049] 150: Processor

[0050] 160: Wheel drive element

[0051] 170: Positioning device

[0052] X, Y, Z: direction

[0053] B: Bottom

[0054] D, D1, D2: distance

[0055] E: Extension direction

[0056] E1, E2: end

[0057] G1, G2, G3: Signal

[0058] O, O1, O2: Object

[0059] S0, S1, S2, S3, S4, S5, S6, S7, S8: Steps

[0060] T: Top

[0061] TD: Target distance

[0062] TO: target object.

Claims

1. A forklift, characterized in that: include: Vehicle body, mast, cargo part, distance sensor, processor and positioning device, The mast member has a bottom end and a top end, the bottom end is fixed to the vehicle body, and the top end is opposite to the bottom end; The cargo carrying part comprises a lifting part and a cargo carrying part, the lifting part is movably arranged on the mast part, and the cargo carrying part is connected to the lifting part and extends along the extension direction; The distance sensor is disposed on the lifting part and is located between the cargo carrying part and the bottom end, and the distance sensor is used to sense the distance of an object in the extension direction of the cargo carrying part; The processor is electrically connected to the distance sensor and is used to determine whether the distance is less than the warning range; as well as The positioning device is disposed at the top end of the mast member to locate the coordinate position of the forklift, and the processor calculates the target distance between the forklift and the target object according to the coordinate position. When the target distance is less than or equal to the warning range, the processor turns off the distance sensor.

2. The stacker according to claim 1, characterized in that: Also includes: The wheel drive element is disposed in the vehicle body and electrically connected to the processor, wherein the processor is used to control the wheel drive element to drive the vehicle body to move, and the processor is used to control the wheel drive element to stop moving the vehicle body when the distance is less than the warning range.

3. The stacker according to claim 1, characterized in that: The distance sensor comprises: A plurality of sensing elements are arranged on the lifting part.

4. The stacker according to claim 1, characterized in that: The distance sensor is an optical distance sensing element.

5. The stacker according to claim 1, characterized in that: The cargo carrier has two opposite ends, one of which is connected to the lifting part, and the extending direction is from one of the two ends connected to the lifting part to the other of the two ends.

6. A control method for a stacker to prevent the stacker from colliding, characterized in that: The stacker includes a vehicle body, a mast, a cargo carrying part, a distance sensor, a processor and a positioning device, the mast having a bottom end and a top end, the cargo carrying part having a lifting part and a cargo carrying part, and the control method includes: By means of the distance sensor, the distance of the object in the extension direction of the cargo carrying part is sensed; By means of the processor, controlling the lifting part to move to a predetermined position along the mast member; Determining, by the processor, whether the distance is less than a warning range; When the distance is greater than or equal to the warning range, controlling the vehicle body to move toward the target object; When the distance is smaller than the warning range, controlling the vehicle to stop moving; Wherein, the control method further includes: Using the positioning device, the coordinate position of the stacker is positioned; Calculating, by the processor, a target distance between the forklift and the target object based on the coordinate position; Determining, by the processor, whether the target distance is less than or equal to the warning range; and When the target distance is less than or equal to the warning range, the processor turns off the distance sensor.

7. The control method for a stacker according to claim 6, characterized in that: When the distance is less than the warning range, the step of controlling the vehicle to stop moving includes: The processor controls the wheel driving element to stop moving the vehicle body.

8. The control method for a stacker according to claim 6, characterized in that: The distance sensor comprises: A plurality of sensing elements are provided, wherein the mast member is fixed to the vehicle body, the lifting part is movably arranged on the mast member, and the plurality of sensing elements are arranged on the lifting part.

9. The control method for a stacker according to claim 6, characterized in that: The distance sensor is an optical distance sensing element.

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