WO2017219640A1

WO2017219640A1 - Trajectory planning method and device for mechanical arm

Info

Publication number: WO2017219640A1
Application number: PCT/CN2016/113194
Authority: WO
Inventors: 罗汉杰
Original assignee: 广州视源电子科技股份有限公司
Priority date: 2016-06-20
Filing date: 2016-12-29
Publication date: 2017-12-28
Also published as: CN106041941A; CN106041941B

Abstract

A trajectory planning method and device for a mechanical arm. The planning method comprises: generating, on the basis of joint parameters of a machine arm that is to work, a work area of the mechanism arm; generating a ray according to the coordinate of a start point input in advance and a moving direction, and calculating intersection points between the ray and the boundary of the work area to generate an intersection point set; calculating the distance between each intersection point in the intersection point set and the start point to obtain the coordinate of an intersection point corresponding to the minimum distance, and marking the intersection point as an end point; and planning the movement trajectory of the mechanical arm on the basis of the coordinate of the start point and the coordinate of the end point. The trajectory planning method for a mechanical arm determines the boundary of the work area of the mechanical arm on the basis of a geometric method, so that a robot can know the position of the end point in advance before moving, thereby facilitating planning the movement trajectory by the robot.

Description

Method and device for trajectory planning of mechanical arm

Technical field

The invention relates to the field of trajectory planning of a mechanical arm, and in particular to a trajectory planning method and device for a mechanical arm.

Background technique

In the working process of the manipulator, the trajectory of the manipulator needs to be planned. Generally, the trajectory planning is implemented by a predetermined speed planning algorithm. For example, an S-type (Double S) speed planning algorithm can be used. To complete the trajectory planning of the robot arm.

Some speed planning algorithms need to receive the start and end points provided by the user in advance when planning the trajectory. Then the program will generate a series of interpolation points between the two points to describe the trajectory of the arm. For example, in the teaching function, the user sends an instruction through the handheld device, so that the robot arm starts from the starting point and moves linearly in a certain direction until reaching the boundary of the working area (ie, the end point).

Among them, the starting position is specified by the user, so it can be obtained very simply, but the position of the end point (ie the boundary of the working area) is determined by the structure of the robot arm and needs to be obtained by monitoring or calculation. The traditional method is realized by continuously monitoring whether the current robot arm has reached the limit position, but this method requires detection of all the position points on the path, and the efficiency is low and the calculation amount is large.

Summary of the invention

In view of the above problems, an object of the present invention is to provide a method and a device for trajectory planning of a robot arm, which can know the position of the end point in advance before the movement, and facilitate the planning of the motion trajectory of the robot.

The invention provides a trajectory planning method for a mechanical arm, comprising the following steps:

Generating a working area of the robot arm based on joint parameters of the robot arm to be operated;

Generating a ray according to a coordinate and a moving direction of the starting point input in advance, and calculating an intersection of the ray and a boundary of the working area to generate a set of intersection points;

Calculating a distance between each intersection point in the intersection set and the starting point, acquiring coordinates of an intersection point corresponding to the minimum distance, and marking the intersection point as an end point;

A motion trajectory of the robot arm is planned based on coordinates of the starting point and coordinates of the end point to control movement of the robot arm according to a planned motion trajectory.

Preferably, the robot arm is a SCARA type robot arm.

Preferably, the joint parameter includes a joint type, an arm length between the joints, and a range of motion of the joint; and the generating the working area of the mechanical arm based on the joint parameter of the mechanical arm to be operated, specifically comprising:

According to the joint type of the robot arm and the relative positional relationship between the joints, a coordinate system for generating each joint is established based on the DH coordinate system;

The working area of the robot arm is generated according to the coordinate system of each joint, the range of motion of each joint, and the arm length between the joints.

Preferably, the generating a ray according to a coordinate and a moving direction of the starting point input in advance, and calculating an intersection of the ray and the boundary of the working area to generate a set of intersection points, specifically:

Decomposing the working area into at least two arcs, obtaining a circle center, a radius, and a central angle range of each arc, and generating an equation of a circle corresponding to each arc;

Generating a ray according to the coordinates and the moving direction of the starting point input in advance, and calculating the intersection of the ray and each circle;

Calculating an arc angle of the intersection point on a circle where the intersection point is located, and when the arc angle angle is within the circle center angle range, storing the intersection point into a preset set to generate a intersection point set.

Preferably, the generating a ray according to the coordinates and the moving direction of the starting point input in advance, and calculating the intersection of the ray and each circle is specifically:

A ray is generated according to the coordinates and the moving direction of the starting point input in advance, and the ray equation is associated with the equation of each circle, and the intersection of the ray and each circle is calculated based on the parametric equation method.

A ray is generated according to the coordinates and the moving direction of the starting point input in advance, and the intersection of the ray and each circle is calculated based on an optimization algorithm of the ray and circle intersection test.

The invention also provides a trajectory planning device for a mechanical arm, comprising:

a work area generating unit, configured to generate a working area of the mechanical arm based on a joint parameter of the mechanical arm to be operated;

An intersection point generating unit configured to generate a ray according to a coordinate and a moving direction of the starting point input in advance, and calculate an intersection of the ray and a boundary of the working area to generate a set of intersection points;

An end point marking unit, configured to calculate a distance between each intersection point in the intersection point set and the starting point, acquire coordinates of an intersection point corresponding to the minimum distance, and mark the intersection point as an end point;

a motion trajectory planning unit is configured to plan a motion trajectory of the robot arm based on coordinates of the starting point and coordinates of the end point to control movement of the robot arm according to a planned motion trajectory.

Preferably, the robot arm is a SCARA type robot arm.

Preferably, the joint parameter includes a joint type, an arm length between the joints, and an active range of the joint; and the working area generating unit specifically includes:

a coordinate system generating module, configured to generate a coordinate system for generating each joint based on a joint type of the robot arm and a relative positional relationship between the joints;

A work area generating module is configured to generate a working area of the robot arm according to a coordinate system of each joint, an active range of each joint, and an arm length between the joints.

Preferably, the intersection set generating unit specifically includes:

a working area decomposition module, configured to decompose the working area into at least two arcs, obtain a circle center, a radius and a central angle range of each arc, and generate an equation of a circle corresponding to each arc;

An intersection calculation module, configured to generate a ray according to a coordinate and a moving direction of the starting point input in advance, and calculate an intersection of the ray and each circle;

a judging module, configured to calculate an arc angle of the intersection point on a circle where the intersection point is located, and when the arc angle angle is within the circle center angle range, determine that the intersection point is located on the arc line, The intersection points are stored in a preset set to generate a set of intersection points.

A method and a device for planning a motion trajectory of a mechanical arm according to an embodiment of the present invention, by calculating a working area of the mechanical arm, and calculating an intersection of a ray generated by a coordinate and a moving direction of the starting point input in advance and a boundary of the working area, and Obtaining the coordinates of the intersection having the smallest distance from the starting point, obtaining an end point corresponding to the starting point and the moving direction, and then planning the motion trajectory according to the starting point and the coordinates of the ending point. The invention is based on a geometric method to determine the boundary of the working area of the robot arm, so that the robot can know the position of the end point in advance before the movement, so that the robot can plan the motion trajectory.

DRAWINGS

In order to more clearly illustrate the technical solutions of the present invention, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention, which are common in the art. For the skilled person, other drawings can be obtained from these drawings without any creative work.

FIG. 1 is a schematic flow chart of a method for trajectory planning of a robot arm according to an embodiment of the present invention.

2 is a schematic structural view of a SCARA type robot arm.

3 is a schematic view of the SCARA type robot arm shown in FIG. 2 in a DH coordinate system.

Fig. 4 is a schematic view showing the working area of the SCARA type robot arm shown in Fig. 2.

Figure 5 is a plan view of the work area shown in Figure 4.

Figure 6 is a schematic view of the connection of the ray to the working area.

FIG. 7 is an algorithm for calculating an intersection of a ray and a circle by an optimization algorithm of a ray-circle intersection test according to an embodiment of the present invention. Schematic diagram of the process.

8(a) to (c) are schematic diagrams of the optimization algorithm shown in Fig. 7.

FIG. 9 is a schematic structural diagram of a trajectory planning device for a robot arm according to an embodiment of the present invention.

FIG. 10 is a schematic structural diagram of a work area generating unit of FIG. 9.

FIG. 11 is a schematic structural diagram of an intersection set generation unit of FIG. 9.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Referring to FIG. 1 , an embodiment of the present invention provides a method for trajectory planning of a robot arm. The trajectory planning method of the robot arm may be performed by a trajectory planning device of a robot arm, and at least includes the following steps:

S101. Generate a working area of the mechanical arm based on joint parameters of the mechanical arm to be operated.

In the embodiment of the present invention, the robot arm is the most widely used automatic mechanical device in the field of robot technology, and is widely used in the fields of industrial manufacturing, medical treatment, entertainment service, military, semiconductor manufacturing, and space exploration. Although they differ in their form, they all share a common feature of being able to accept instructions and accurately position them at a certain point in the three-dimensional (or two-dimensional) space according to the instructions.

In general, a robotic arm includes a plurality of joints, each joint having joint parameters, which may include joint type, arm length (length of the connecting arm connecting the two joints), range of motion, and the like. Wherein, the joint type may include a rotating joint and a sliding joint, the rotating joint may control the rotation of the connecting arm, and the sliding joint may realize the vertical sliding of the connecting arm. The working area of the robot arm can be controlled by a combination of different joints. Specifically, the working area of the robot arm can be determined by the following steps:

S1011, according to the joint type of the robot arm and the relative positional relationship between the joints, a coordinate system for generating each joint is established based on the DH coordinate system.

As shown in FIG. 2, a SCARA (Selective Compliant Articulated Robot for Assembly) type robot arm is exemplified, which has four joints J1, J2, J3, and J4, wherein J1, J2, and J4 are rotating joints, and J1 and J2, J2 and J4 are connected by corresponding connecting arms, and J3 is a sliding joint. Of course, it should be understood that the present invention is also applicable to other types of robot arms, and details are not described herein.

After determining the above joints, it is necessary to establish a coordinate system for each joint. As shown in Fig. 3, the coordinate system of each joint can be established based on the DH (Denavit-Hartenberg) coordinate system, wherein the rotational axes of the rotating joints Ji and their respective The zi axis (the connecting arm of the rotating joint Ji rotates around the zi axis) is parallel to each other, the arm length of the connecting arm is αi, {i|i∈{1, 2, 4}}; the axis of the sliding joint J3 (z3 axis) and J4 The axes (z4 axes) are parallel. After the zi axis is determined, the direction of the first joint pointing to the second joint can be used as the xi direction, and the direction of yi can be determined based on the right hand rule, thus, the coordinate system of each joint is generated.

S1012: Generate a working area of the robot arm according to a coordinate system of each joint, an active range of each joint, and an arm length between the joints.

In the embodiment of the present invention, after generating the coordinate system of each joint, according to the range of motion of each joint (for the rotating joint, the range of motion is the range of the angle of rotation of the connecting arm rotation, and for the sliding joint, the range of motion is The upper and lower movement range of the connecting arm can generate the working area of the mechanical arm (as shown in FIG. 4). At this time, it is only necessary to project on the plane to generate a top view as shown in FIG. 5.

S102: Generate a ray according to the coordinates and the moving direction of the starting point input in advance, and calculate an intersection of the ray and the boundary of the working area to generate a set of intersection points.

Specifically, when teaching with a robot arm, the most common function is that the user sends an instruction through the handheld device, so that the robot arm starts from a preset starting point and moves linearly in a certain direction until reaching the working area. The boundary (end point). In the embodiment of the present invention, in order to obtain the end point, the robot arm may include:

S1021: Decompose the working area into at least two arcs, obtain a circle center, a radius, and a central angle range of each arc, and generate an equation of a circle corresponding to each arc.

As can be seen from Figure 5, the working area of the robot arm is

Four arcs are enclosed. The four arcs are located on four circles: ⊙O ₁ , ⊙O ₂ , ⊙O ₃ , ⊙O ₄ . The center O ₁ , O ₄ coincides with the J ₁ axis; O ₂ and O ₃ are the positions of the J ₂ axis when the J ₁ axis is rotated to the positive and negative limits, respectively.

with

The maximum range of motion in the positive/negative direction of the axis J _i , respectively

^{^{{j i | -π≤j i ≤π}}} .

The detailed parameters of these four arcs can be seen in Table 1:

Table 1

among them:

S1022: Generate a ray according to the coordinates and the moving direction of the starting point input in advance, and calculate an intersection of the ray and each circle.

In the embodiment of the present invention, it is assumed that the starting point is I, the direction vector is n, and ||n|| is a unit vector of the direction vector n. Then the ray can be expressed as R(u)=I+u·||n||.

If the starting point I is in the working area, the ray R(u) must intersect with a circle ⊙O _i

Wherein, when calculating the intersection point, the equation of the ray R(u) can be sequentially connected with the equation of each circle, and obtained by using the parametric equation method.

S1023, calculating an arc angle of the intersection point on a circle where the intersection point is located, and when the arc angle angle is within the circle center angle range, determining that the intersection point is located on the arc line, and depositing the intersection point A preset collection that generates a collection of intersections.

In the embodiment of the present invention, some of the intersections obtained above intersect with the circle, but are not located on the arc, and thus need to be removed. Specifically, as shown in FIG. 6, the ray IP intersects ⊙O ₁ at point N, respectively; ⊙O ₂ intersects point K and point M; ⊙O ₄ intersects point J and point L; and ⊙O ₃ does not Intersection. Wherein, the points K, N are on the circle, but are not on the arc of the working area, so after obtaining the intersection point, it is also necessary to check whether the arc angle θ ^{i of} the intersection point satisfies

Specifically, assuming that the point s (x, y) is a point on ⊙O _i, with respect to the point s ⊙O _i θ ⁱ is the angle in radians:

Through the above formula, you can determine which intersections are on the arc and which are not. At this point, those intersections located on the arc are stored in the preset set ξ={κ ⁱ } to generate a set of intersections.

It should be noted that, in other embodiments of the present invention, the working area does not necessarily consist of an arc of a circle. For example, the working area may be composed of an elliptical arc or a mixture of arcs of different types of geometric shapes. At this time, similarly, the equations and angular ranges of the geometric shapes corresponding to the arcs may be obtained, and then The method can be used to calculate and generate a set of intersection points. These technical solutions are all within the scope of the present invention and will not be described herein.

S103. Calculate a distance between each intersection point in the intersection set and the starting point, and obtain an intersection point corresponding to the minimum distance. Coordinates and mark the intersection as the end point.

In the embodiment of the present invention, the distance between each intersection point and the starting point I can be calculated by the Euler formula, and then each calculated distance is compared, and the coordinates of the intersection point corresponding to the minimum distance are obtained, and the The intersection point is marked as the end point, at which point the boundary of the desired work area is obtained.

S104. Plan a motion trajectory of the robot arm based on coordinates of the starting point and coordinates of the end point to control movement of the robot arm according to a planned motion trajectory.

In the embodiment of the present invention, after obtaining the coordinates of the end point corresponding to the starting point and the moving direction, the motion trajectory of the robot arm may be planned according to the coordinates of the starting point and the coordinates of the ending point. .

For example, taking a typical S-type speed planning algorithm as an example, after receiving the coordinates of the starting point and the coordinates of the ending point, a seven-segment motion process can be planned, and the seven-segment motion process is realized. The robot arm moves smoothly and rapidly from the starting point (the initial velocity is zero) to the end point (the final velocity is also zero).

In summary, the method for planning a motion trajectory of a mechanical arm according to an embodiment of the present invention generates a working area of the mechanical arm, and then calculates a boundary between a ray generated by a coordinate and a moving direction of the starting point input in advance and a boundary of the working area. And intersecting the coordinates of the intersection point having the smallest distance from the starting point, obtaining an end point corresponding to the starting point and the moving direction, and then planning the motion trajectory according to the starting point and the coordinates of the ending point. The invention is based on a geometric method to determine the boundary of the working area of the robot arm, so that the robot can know the position of the end point in advance before the movement, so that the robot can plan the motion trajectory.

In order to facilitate an understanding of the present invention, some preferred embodiments of the present invention are further described below.

Preferably, for step S1022, after the ray is generated, a conventional parametric equation method may be used to find an intersection point, or may be used.

An optimization algorithm based on the ray and circle intersection test is proposed to calculate the intersection of the ray and each circle.

Specifically, as shown in FIG. 7, the parameter equation of the ray is R(u)=I+u·||n||, where ||n|| is a unit length. As shown in Fig. 8(a), first calculate the vector from the starting point I to the center of the circle O _i

vector

length

And vector

Projection along the ||n|| direction

If a ² >r _i ² and l<0, then the starting point is outside ⊙O _i and the direction of the ray extends away from the ⊙O _i direction, so the ray does not intersect ⊙O _i (Fig. 8(b) As shown), the first exclusion test is completed at this time. Otherwise, use the Pythagorean theorem to calculate the square of the distance between the center O _i and the projection: m ² = a ^{2 -} l ² , if m ² > r _i ² , then it can be determined that the ray and the circle O _i must not intersect, complete the first Secondary exclusion test. If the ray and ⊙O _{i are} subjected to two exclusion tests, it can be determined that they must intersect. Next, calculate the intersection of the ray and ⊙O _i : first, calculate the distance

Then, it is determined whether the starting point I is located in ⊙O _i . If a ² >r _i ² , then the starting point I is located outside the ⊙O _i . At this time, the ray has two intersections with the circle O _i , respectively

as well as

(As shown in Figure 8(a)). If a ² <r _i ² , then the starting point I is located in the circle O _i . At this time, the ray has an intersection with the circle O _i , which is I+(l+q)·||n|| (Fig. 8( c) shown).

In the preferred embodiment, before calculating the intersection of the ray and the circle, it is first determined whether there is an intersection of the ray and the circle by two tests. In the calculation, only the circle having the intersection with the ray is calculated, and there is no need for those points that do not intersect with the ray. The circle is calculated, thus reducing the amount of calculation and improving the calculation efficiency.

Referring to FIG. 9 , an embodiment of the present invention further provides a trajectory planning apparatus 100 for a robot arm, including:

The work area generating unit 10 is configured to generate a working area of the mechanical arm based on joint parameters of the mechanical arm to be operated.

The intersection set generating unit 20 is configured to generate a ray according to the coordinates and the moving direction of the starting point input in advance, and calculate an intersection of the ray and the boundary of the working area to generate a set of intersection points;

The end point marking unit 30 is configured to calculate a distance between each intersection point in the intersection point set and the starting point, acquire coordinates of an intersection point corresponding to the minimum distance, and mark the intersection point as an end point;

The motion trajectory planning unit 40 is configured to plan a motion trajectory of the robot arm based on the coordinates of the starting point and the coordinates of the end point to control the motion of the robot arm according to the planned motion trajectory.

Preferably, the mechanical arm is a SCARA type mechanical arm.

Preferably, the working area generating unit 10 specifically includes:

The coordinate system generating module 11 is configured to establish a coordinate system for generating each joint based on the joint type of the robot arm and the relative positional relationship between the joints based on the DH coordinate system.

The working area generating module 12 is configured to generate a working area of the mechanical arm according to a coordinate system of each joint, an active range of each joint, and an arm length between the joints.

Preferably, please refer to FIG. 11 together, the intersection set generating unit 20 specifically includes:

The working area decomposition module 21 is configured to decompose the working area into at least two arcs, obtain a circle center, a radius and a central angle range of each arc, and generate an equation of a circle corresponding to each arc.

The intersection calculation module 22 is configured to generate a ray according to the coordinates and the moving direction of the starting point input in advance, and calculate an intersection of the ray and each circle.

Wherein, the intersection calculation module 22 can directly calculate the intersection of the ray and each circle, and directly calculate the ray and each circle, or calculate the algorithm based on the intersection of the ray and the circle intersection test. The intersection of the ray and each circle is not specifically limited in the present invention.

a judging module 23, configured to calculate a radian angle of the intersection point on a circle where the intersection point is located, and is located at the radian angle When the central angle is within the range, it is determined that the intersection is located on the arc, and the intersection is stored in a preset set to generate a set of intersections.

In summary, the motion trajectory planning apparatus 100 of the robot arm according to the embodiment of the present invention generates the working area of the robot arm by the working area generating unit 10, and then calculates the starting point input by the intersection point generating unit 20. The coordinates and the intersection of the ray generated by the moving direction and the boundary of the working area, and the coordinates of the intersection having the smallest distance from the starting point are acquired by the end marking unit 30, the end point corresponding to the starting point and the moving direction is obtained, and finally the motion The trajectory planning unit 40 performs planning of the motion trajectory according to the starting point and the coordinates of the ending point. The invention is based on a geometric method to determine the boundary of the working area of the robot arm, so that the robot can know the position of the end point in advance before the movement, so that the robot can plan the motion trajectory.

The above disclosure is only a preferred embodiment of the present invention, and of course, the scope of the present invention is not limited thereto, and those skilled in the art can understand all or part of the process of implementing the above embodiments, and according to the present invention. The equivalent changes required are still within the scope of the invention.

One of ordinary skill in the art can understand that all or part of the process of implementing the foregoing embodiments can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium. When executed, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

Claims

A method for trajectory planning of a robot arm, comprising the steps of:

Generating a working area of the robot arm based on joint parameters of the robot arm to be operated;

Generating a ray according to a coordinate and a moving direction of the starting point input in advance, and calculating an intersection of the ray and a boundary of the working area to generate a set of intersection points;

Calculating a distance between each intersection point in the intersection set and the starting point, acquiring coordinates of an intersection point corresponding to the minimum distance, and marking the intersection point as an end point;

A motion trajectory of the robot arm is planned based on coordinates of the starting point and coordinates of the end point to control movement of the robot arm according to a planned motion trajectory.
The trajectory planning method for a robot arm according to claim 1, wherein the mechanical arm is a SCARA type mechanical arm.
A trajectory planning method for a robot arm according to claim 1, wherein

The joint parameters include joint type, arm length between joints, and range of motion of the joint;

The working area of the mechanical arm is generated based on the joint parameters of the mechanical arm to be operated, and specifically includes:

According to the joint type of the robot arm and the relative positional relationship between the joints, a coordinate system for generating each joint is established based on the DH coordinate system;

The working area of the robot arm is generated according to the coordinate system of each joint, the range of motion of each joint, and the arm length between the joints.
The trajectory planning method for a robot arm according to claim 1, wherein the ray is generated according to a coordinate and a moving direction of a start point input in advance, and an intersection of the ray and a boundary of the working area is calculated. Generate a set of intersection points, specifically:

Decomposing the working area into at least two arcs, obtaining a circle center, a radius, and a central angle range of each arc, and generating an equation of a circle corresponding to each arc;

Generating a ray according to the coordinates and the moving direction of the starting point input in advance, and calculating the intersection of the ray and each circle;

Calculating an arc angle of the intersection point on a circle where the intersection point is located, and when the arc angle angle is within the circle center angle range, storing the intersection point into a preset intersection point set to generate a intersection point set.
The trajectory planning method for a robot arm according to claim 4, wherein the ray is generated according to the coordinates and the moving direction of the starting point input in advance, and the intersection of the ray and each circle is calculated as follows:

A ray is generated according to the coordinates and the moving direction of the starting point input in advance, and the ray equation is associated with the equation of each circle, and the intersection of the ray and each circle is calculated based on the parametric equation method.
The trajectory planning method of the robot arm according to claim 4, wherein the generating a ray according to the coordinates and the moving direction of the starting point input in advance, and calculating the intersection of the ray and each circle is specifically:

A ray is generated according to the coordinates and the moving direction of the starting point input in advance, and the intersection of the ray and each circle is calculated based on an optimization algorithm of the ray and circle intersection test.
A trajectory planning device for a mechanical arm, comprising:

a work area generating unit, configured to generate a working area of the mechanical arm based on a joint parameter of the mechanical arm to be operated;

An intersection point generating unit configured to generate a ray according to a coordinate and a moving direction of the starting point input in advance, and calculate an intersection of the ray and a boundary of the working area to generate a set of intersection points;

An end point marking unit, configured to calculate a distance between each intersection point in the intersection point set and the starting point, acquire coordinates of an intersection point corresponding to the minimum distance, and mark the intersection point as an end point;

a motion trajectory planning unit is configured to plan a motion trajectory of the robot arm based on coordinates of the starting point and coordinates of the end point to control movement of the robot arm according to a planned motion trajectory.
The trajectory planning device for a robot arm according to claim 7, wherein the robot arm is a SCARA type robot arm.
A trajectory planning device for a robot arm according to claim 7, wherein

The joint parameters include joint type, arm length between joints, and range of motion of the joint;

The working area generating unit specifically includes:

a coordinate system generating module, configured to generate a coordinate system for generating each joint based on a joint type of the robot arm and a relative positional relationship between the joints;

A work area generating module is configured to generate a working area of the robot arm according to a coordinate system of each joint, an active range of each joint, and an arm length between the joints.
The trajectory planning device of the robot arm according to claim 7, wherein the intersection set generating unit specifically comprises:

a working area decomposition module, configured to decompose the working area into at least two arcs, obtain a circle center, a radius and a central angle range of each arc, and generate an equation of a circle corresponding to each arc;

An intersection calculation module, configured to generate a ray according to a coordinate and a moving direction of the starting point input in advance, and calculate an intersection of the ray and each circle;

a judging module, configured to calculate an arc angle of the intersection point on a circle where the intersection point is located, and when the arc angle angle is within the circle center angle range, determine that the intersection point is located on the arc line, The intersection points are stored in a preset set to generate a set of intersection points.