TWI701122B - Multi-axis robot arm system and path planning method thereof - Google Patents

Abstract

A multi-axis robot arm system having a multi-axis robot arm and a processor is provided. The processor obtains a best route data and a best posture data from an initial location to a target location according to an initial posture information, the initial location, a target posture information and the target location. The processor further obtains a second posture information and a second route data from an initial location to a target location according to the best route data and a best posture data. The processor integrates the best posture data, the second posture data and the best route data and the second route data, so as to generate a working path of the multi-axis robot arm.

Description

Multi-axis mechanical arm system and path planning method thereof

The present invention relates to a path planning technology, and particularly relates to a multi-axis robotic arm system and a path planning method thereof.

Under the trend of automation, robotic arms have actually been used in industries such as automated manufacturing and warehouse management. In particular, the multi-axis robot arm has a high degree of freedom and can move freely in space, which is a trend in the field of industrial robots. In order to maintain the mobile efficiency of the robotic arm and maintain the safety of the plant, path planning is an important part. However, due to the high degree of freedom, the path planning process will be relatively complicated. Based on this, how to provide path planning while also providing a more efficient path planning process is a subject for those skilled in the art.

The invention provides a multi-axis mechanical arm system and a path planning method thereof to provide a more efficient path planning process.

An embodiment of the present invention provides a multi-axis robotic arm system, which has Multi-axis robotic arm and processing unit. The multi-axis robot arm has at least one front axle unit, at least one rear axle unit, and a control unit. The processing unit is electrically connected to the multi-axis robotic arm. The processing unit calculates the best path data and the corresponding best of the front axis unit from the start position to the target position based on the start posture information, start position, target posture information, and target position Posture information. The processing unit calculates the second posture data and corresponding second path data of the rear axle unit from the starting position to the target position based on the best path data and the best posture data. The processing unit further integrates the best posture data and the second posture data, as well as the best path data and the second path data respectively, to generate a working path of the multi-axis robotic arm.

An embodiment of the present invention provides a path planning method for a multi-axis robotic arm, which has the following steps. According to a starting posture information, a starting position, a target posture information and a target position, the best path data and best posture data of at least one front axle unit of the multi-axis robot arm from the starting position to the target position are acquired; Best path data and best posture data, acquire second posture data and second path data of at least one rear axle unit of the multi-axis robotic arm from the starting position to the target position; and integrate the best posture data, second posture data, The best path data and the second path data are used to generate a working path of the multi-axis robotic arm.

Based on the above, the multi-axis robotic arm system and the multi-axis robotic arm path planning method of the present invention respectively calculate the optimal path according to the front axis unit and the rear axis unit of the robot arm. Since the degree of freedom of the axis unit for path planning is reduced each time, it can effectively reduce the complexity of path planning and speed up path planning. degree. At the same time, the path obtained by the multi-axis robotic arm system and the multi-axis robotic arm path planning method is composed of the optimal path of the front axis unit and the optimal path of the rear axis unit. Based on this, it is a trade-off between the speed of path planning and the best path.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

110: Multi-axis robotic arm

113~115: Front axle unit

116~118: Rear axle unit

120: processing unit

S210~S230: steps

S: starting position

D: target location

Fig. 1 shows a system schematic diagram of a multi-axis robotic arm system according to an embodiment of the present invention.

2 is a schematic flowchart of a path planning method for a multi-axis robotic arm according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a virtual space according to an embodiment of the invention.

4 is a schematic diagram of a configuration space according to an embodiment of the present invention.

Fig. 1 shows a system schematic diagram of a multi-axis robotic arm system according to an embodiment of the present invention. Please refer to FIG. 1, in the embodiment of the present invention, the multi-axis robot arm system has at least one front axle unit, at least one rear axle unit, and one control unit. The multi-axis robot arm 110 and the processing unit 120 are provided. The multi-axis robotic arm 110 has a plurality of joints 113-118, and a control unit (not shown) installed inside the robotic arm. Moreover, the multi-axis robot arm is a tandem robot arm, that is to say, each axis unit will Displace and rotate in one axis, and drive other axes to move together.

In the following description, the axle unit is logically divided into a front axle unit and a rear axle unit, and during path planning, the paths of the front axle unit and the rear axle unit are planned separately. Taking the embodiment of FIG. 1 as an example, the shaft unit 113 arranged inside the base and the shaft units 114 to 115 close to the base are regarded as front axle units, and the shaft units 116 to 118 far from the base are regarded as rear axle units. The distinction between the front axle units 113 to 115 and the rear axle units 116 to 118 will be adjusted according to the actual path planning design. It should be noted that, in an embodiment of the present invention, the path planning uses Configuration Space to estimate the motion range and situation of the robotic arm in space. Therefore, in the embodiment of the present invention, including but not limited to, the number of the front axle unit is three, so that the front axle unit can be transformed and analyzed in the configuration space.

The control unit is electrically connected to the front axle units 113 to 115 and the rear axle units 116 to 118 for receiving control signals to control the movement of the multi-axis robotic arm 110 in each axis. The control unit can be implemented with any type of control chip, and the present invention is not limited to this.

In the embodiment of the present invention, the robot arm is supported by the base. The shaft units 113 to 118 are arranged on the base, and are used for rotating and displacing the mechanical arm in each axial direction through its own movement. In addition, each of the shaft units 113-118 moves in a different axial direction. In the embodiment of the present invention, each shaft unit 113-118 is implemented by a motor.

The processing unit 120 is electrically connected to the robotic arm 110 for executing various logics Edit calculations, and carry out path planning. The processing unit 120 is, for example, a central processing unit (Central Processing Unit, CPU), or other programmable general-purpose or special-purpose microprocessor (Microprocessor), digital signal processor (Digital Signal Processor, DSP), Programmable controller, Application Specific Integrated Circuit (ASIC) or other similar components or a combination of the above components, the present invention is not limited to this.

2 is a schematic flowchart of a path planning method for a multi-axis robotic arm according to an embodiment of the present invention. The embodiment of FIG. 2 is at least applicable to the multi-axis robotic arm system depicted in the embodiment of FIG. 1. Therefore, the process of running the multi-axis robotic arm path planning method with the multi-axis robotic arm system will be described below with reference to FIGS. 1 and 2.

When running the robot arm path planning method, the operator will select the target position and posture of the robot arm.

In step S210, the processing unit 120 calculates the best path data from the start position to the target position of the front axle units 113~115 and the corresponding best posture data according to the start posture information, start position, target posture information, and target position. . Specifically, in an embodiment of the present invention, the starting position, starting attitude information, target position, and target attitude information are all known. In other words, the specific starting position and final position of each front axle unit 113 to 115 are known. Based on this, the processing unit 120 can arrange a path in space according to the known starting position and target position.

In an embodiment of the disclosure, the processing unit 120 is based on a path search method, such as A* search algorithm, D* search algorithm, or Dijkstra's algorithm, to search for at least one path Calculate the best posture data of the front axle units 113-115 from the starting position to the target position, and the corresponding best path data. For example, if the starting positions of the front axle units 113 to 115 are set to (0, 0, 0) and the target position is set to (-70, -30, 20), the processing unit 120 obtains the front axle unit 113 The best target position of ~115 and the path of the best target posture are shown in Table 1:

It should be noted that, in this embodiment, the “best” mentioned in the best path and best posture is the best path and best posture generated in the way the processing unit 120 runs. For example, the A* search algorithm will take the path with the least moving cost as the best path. At this time, if the processing unit 120 adopts the A* search algorithm, the best path and the best posture are the path with the least moving cost and the corresponding posture. In other words, the best path and best posture will be based on the calculation used by the processing unit 120 The method makes the result different, and the present invention is not limited to this.

In step S220, the processing unit 120 calculates the second posture data and the corresponding second path data from the starting position to the target position of the rear axle units 116-118 based on the best path data and the best posture data. In other words, the processing unit 120 will be limited by the best path and best posture of the front axle units 113 to 115, so that the movement range (degrees of freedom) of the multi-axis robotic arm 110 is only three of the corresponding rear axle units 116 to 118. The state of the axis. Based on this, the optimal second path of the corresponding rear axle units 116 to 118 is further calculated. From the perspective of the path, that is to say, the processing unit 120 will perform calculations based on the posture data of the front axle units 113 to 115 at the t-th step to generate the second posture data at the t+1-th step. The second step data and second posture data of the six axes are shown in Table 2:

In the last step of step S220, the postures of the front axle units 113 to 115 are respectively (-70, -30, 20). Therefore, the processing unit 120 obtains the paths of the rear axle units 116 to 118 based on the postures of the front axle units 113 to 115 being (-70, -30, 20). Moreover, in the embodiment of the present invention, the processing unit 120 calculates the best posture data and the corresponding best path data from the starting position to the target position of the front axle units 113 to 115 corresponding to step S220. The best posture data of the axis units 116-118 from the starting position to the target position and the corresponding best path data. That is to say, the processing unit 120 obtains the rear axle unit according to the part of the corresponding rear axle unit in the starting position and the starting attitude information, the best path data and the last path and attitude in the best attitude data, and the target position. The second posture data and the second path data from the starting position to the target position.

在整合的工作路徑中，路徑0至路徑14是在步驟S220中所產生的最佳路徑資料及最佳路徑姿態，路徑15到路徑33是在步驟S230中所產生的路徑1至18。並且，在整合最佳路徑資料及第二路徑資料之後，處理單元120會進一步在路徑33及路徑34的時候， 依據目標位置對多軸機械手臂110校正偏差。 In step S230, the processing unit 120 further integrates the best posture data and the second posture data, as well as the best path data and the second path data, respectively, to generate the working path of the multi-axis robot arm. The integrated working path is shown in Table 3 for example:

In the integrated working path, path 0 to path 14 are the best path data and the best path attitude generated in step S220, and path 15 to path 33 are paths 1 to 18 generated in step S230. Moreover, after integrating the best path data and the second path data, the processing unit 120 will further correct the deviation of the multi-axis robot arm 110 during the path 33 and the path 34 according to the target position.

It should be noted that the processing unit 120 does not directly plan the overall path and posture of all axis units from the path and posture from the starting position to the target position. Therefore, the working path is not necessarily the shortest path among all possible paths. However, by separating the front axle units 113 to 115 and the rear axle units 116 to 118 to plan the path, the time spent in path planning can be greatly reduced, so as to achieve a trade-off between the optimal working path and the working path planning time.

It is worth mentioning that, in order to ensure that the multi-axis robot arm will not be interfered by obstacles during operation, in an embodiment of the present invention, the processing unit 120 also creates a configuration space (Configuration Space). FIG. 3 is a schematic diagram of a virtual space according to an embodiment of the invention. Specifically, the processing unit 120 may be electrically connected to a camera to photograph the environment, or may receive images input from the operator to the processing unit 120 to establish a three-dimensional virtual space.

With three virtual spaces, the processing unit 120 will further create a configuration space corresponding to each joint. In addition, the processing unit 120 generates the front axle path information and the front axle posture information of the front axle unit in the configuration space. In detail, the processing unit 120 simulates all the movement situations of the front axle units 113 to 115 of the multi-axis robotic arm 110 in the configuration space, so as to divide the movement area of the multi-axis robotic arm 110 into interference situations and non-interference situations. 4 is a schematic diagram of a configuration space according to an embodiment of the present invention. Please refer to Figure 4, S represents the starting position, D represents the target 标 location. The geometric patterns represent obstacles. Based on this, the processing unit 120 can determine which of all the movement paths of the front axle units 113 to 115 will cause the multi-axis robotic arm 110 to hit an obstacle, and which will make the multi-axis robotic arm 110 reach the target position smoothly. Based on this, the processing unit 120 integrates the paths that hit the obstacle to form a moving area that will hit the obstacle, and marks the moving area as an interference situation, and the remaining moving areas are in a non-interference situation. Based on this, the processing unit 120 can exclude the front axle unit from falling into the interference movement area in advance when step S220 is executed, and generate the front axle path information and front axle attitude information of the front axle unit accordingly, so as to reduce the processing unit 120 The burden of performing unnecessary calculations.

It is worth mentioning that in the embodiment of the present invention, the multi-axis robotic arm is a six-axis robotic arm as an example. However, in other embodiments, the multi-axis robotic arm can also be 2-axis, 3-axis, or even 9-axis. Axis, 10-axis, the present invention is not limited to this. The only thing to note is that if the multi-axis robot arm exceeds 6 axes, the axis unit can be divided into a front axis unit and multiple groups of rear axis units. For example, the processing unit 120 can plan the path of the first group of rear axle units based on the best path data and best attitude data of the front axle unit. Then, the processing unit 120 uses the path of the front axle unit and the first group of rear axle units as a reference, and then plans the path of the second group of rear axle units. However, the present invention is not limited to this.

To sum up, the multi-axis robotic arm system and the multi-axis robotic arm path planning method of the present invention will respectively calculate the optimal path according to the front axis unit and the rear axis unit of the robot arm. Since the degree of freedom of the axis unit for path planning is reduced each time Therefore, it can effectively reduce the complexity of path planning and accelerate the speed of path planning. At the same time, the path obtained by the multi-axis robotic arm system and the multi-axis robotic arm path planning method is composed of the optimal path of the front axis unit and the optimal path of the rear axis unit. Based on this, it is a trade-off between the speed of path planning and the best path.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

113~115: Front axle unit

116~118: Rear axle unit

120: processing unit

Claims (9)

A multi-axis robotic arm system includes: a multi-axis robotic arm having at least one front axle unit, at least one rear axle unit, and a control unit; and a processing unit, electrically connected to the multi-axis robotic arm, according to a start Posture information, a starting position, a target posture information and a target position, the best path data and best posture data of the front axle unit from the starting position to the target position are obtained; wherein the processing unit is based on the best path Data and the best posture data, obtain a second posture data and second path data of the rear axle unit from the starting position to the target position, and the processing unit integrates the best posture data, the second posture data, The best path data and the second path data are used to generate a working path of the multi-axis robotic arm. The multi-axis robotic arm system described in item 1 of the scope of patent application, wherein the processing unit creates a configuration space (Configuration Space) based on environmental image information, and generates the front axis path of the front axis unit in the configuration space Information and front axle attitude information. For example, the multi-axis robotic arm system described in item 2 of the scope of patent application, wherein the processing unit obtains the optimal path data and the corresponding path from the front axle path information and front axle posture information through a path search method Best posture information. For example, the multi-axis robotic arm system described in item 3 of the scope of patent application, wherein the path search method includes A* search algorithm, D* search algorithm or Dijkstra's algorithm, by which the processing The unit calculates the best path data of the front axle unit and the corresponding best posture data. The multi-axis robotic arm system described in item 1 of the scope of patent application further includes a base, and the front axle unit is connected to the base, the rear axle unit, and the control unit, and the front axle unit and the control unit The rear axle units move in different axial directions. A path planning method for a multi-axis robotic arm includes: obtaining at least one front axis unit of a multi-axis robotic arm from the initial position to the target based on a starting attitude information, a starting position, a target attitude information, and a target position The best path data and best posture data of the position; according to the best path data and the best posture data, obtain the second posture of at least one rear axis unit of the multi-axis robotic arm from the starting position to the target position Data and second path data; and integrating the best posture data, the second posture data, the best path data, and the second path data to generate a working path of the multi-axis robotic arm. For example, the multi-axis robot arm path planning method described in item 6 of the scope of patent application further includes: establishing a configuration space according to an environmental image information, and generating the front axis path of the front axis unit in the configuration space Information and front axle pose State information. For example, the method for path planning of a multi-axis robotic arm as described in item 7 of the scope of patent application, wherein, based on the initial attitude information, the initial position, the target attitude information, and the target position, the multi-axis robotic arm is obtained The step of the best path data and best posture data of the front axle unit from the starting position to the target position includes: obtaining the best path data from the front axle path information and the front axle posture information through a path search method The best path data and the corresponding best posture data. For example, the path planning method of the multi-axis robotic arm described in the scope of patent application, wherein the path search method includes A* search algorithm, D* search algorithm or Dijkstra's algorithm, whereby Calculate the best posture data and the corresponding best path data of the front axle unit from the starting position to the target position.

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