TRAJECTORY PROGRAMMING METHOD FOR ROBOT

Abstract

TRAJECTORY PROGRAMMING METHOD FOR A ROBOT The present invention relates to a method for acquiring trajectory points for a robot (2), comprising the following steps: - positioning the robot in an initial rest position; - learning a trajectory (10) by means of an operator holding a trajectory generation device (6) equipped with means for detecting position in space; - generating and transmitting the trajectory to the robot, notable in that said device is configured to be mounted on the robot in its initial rest position and to be detached from said robot during the learning step, the mounting of the device on the robot being ensured by means of a junction interface (4) between the robot and said device, providing a common reference frame (8) between the robot and said device. (Figure to be published with the abbreviation: Figure 3)

Description

Title of the invention: METHOD FOR PROGRAMMING TRAJECTORY FOR ROBOT technical field

[0001] The present invention relates to the field of robots, in particular trajectory learning for industrial and collaborative robots, especially for applications in the automotive field. Previous technique

[0002] Industrial and collaborative robots are widely used in the manufacturing and assembly of modern motor vehicles. To perform specific tasks, particularly to replace human operators, these robots are programmed by trajectory learning, often manually. One commonly used method for this learning is direct manual manipulation of the robot, where the operator physically guides the robot along the desired trajectory, such as trajectory generation on a simulated station (FTS) for a collaborative robot.

[0003] Such a method is described in published patent document US 2013 / 0245824 A1, in which an operator physically manipulates the robot's gripper to move an object between two different points in space. However, this approach has a major limitation: the acquired trajectory does not reflect that achieved by a human, due to the lack of agility and precision inherent in the manual method of point acquisition.

[0004] An alternative to this direct manipulation is the use of motion tracking and capture systems, which allow trajectories to be generated using a tool equipped with a constellation, without requiring the robot to be manipulated. However, this approach encounters implementation difficulties, particularly due to alignment problems between the point acquisitions, the robot, and the surrounding elements.

[0005] Published patent document US 2019 / 0168390 Al discloses a method for capturing the movements of a tool held by an operator using a motion capture system with cameras, thereby enabling the robot to reproduce these movements. Although this method eliminates the need for manual manipulation of the robot, it does not completely resolve the aforementioned problems, particularly with regard to the accuracy of the measured data and its transmission to the robot. Description of the invention

[0006] The present invention aims to overcome at least one of the drawbacks of the aforementioned prior art. More particularly, the invention aims to provide a simple and effective solution for accurately teaching a robot to reproduce the movements of an operator by following a defined trajectory.

[0007] To this end, the invention relates to a method for acquiring trajectory points for a robot, comprising the following steps: - positioning the robot in an initial resting position; - learning a trajectory by means of an operator taking control of a trajectory generation device equipped with means of detecting position in space; - generation of the trajectory by the trajectory generation device and transmission of said trajectory to the robot, in view of a reproduction of said trajectory by the robot; remarkable in that the trajectory generation device is configured to be mounted on the robot in the initial rest position and to be detached from said robot during the learning stage, the mounting of the device on the robot being ensured by means of a junction interface between the robot and said device, said junction interface ensuring a common reference frame between the robot and said device when it is mounted on said robot.

[0008] According to one embodiment, the trajectory learning step includes recording coordinates of points of said trajectory in the reference frame.

[0009] According to one embodiment, said method further includes a step of mounting an operational module on the robot, replacing the trajectory generation device after the trajectory has been transmitted to the robot, said operational module including a Cartesian coordinate system configured to coincide with the reference coordinate system at the junction interface.

[0010] The invention also relates to a computer program comprising computer-readable code instructions, notable in that said program leads the computer to implement the trajectory point acquisition method for a robot according to the invention, when said program is executed by a computer.

[0011] The invention also relates to a unit comprising a computer-readable recording medium, notable in that the computer program according to the invention is recorded on the recording medium.

[0012] In addition, the invention relates to a robot, remarkable in that it is configured to perform the trajectory point acquisition method according to the invention.

[0013] According to one embodiment, said robot comprises a first Cartesian coordinate system disposed at a distal end of said robot at the junction interface, and the trajectory generation device includes a second Cartesian frame, said first and second Cartesian frames being superimposed by means of the junction interface when said device is mounted on the robot, so as to form the common reference frame.

[0014] The measures of the invention are advantageous in that they make it possible to overcome the disparities between the different reference points, thus guaranteeing the learning and the precise and agile reproduction of trajectories, including those which are manual and difficult to model mathematically.

[0015] The invention also makes it possible to acquire trajectory points without using the robot, thus eliminating the constraints associated with it. Furthermore, it is compatible with all types of industrial and collaborative robots. Brief description of the drawings

[0016] [Fig-1] represents the steps of a trajectory point acquisition process for a robot, according to the present invention;

[0017] [Fig.2] illustrates a robot according to the invention comprising a generation device trajectory designed to be mounted and dismounted on the robot using a junction interface;

[0018] [Fig.3] illustrates a trajectory generated by the trajectory generation device of the [Fig.2], Detailed description

[0019] Fig. 1 represents the steps of a method 100 for acquiring trajectory points for a robot according to the present invention, said robot, illustrated in Figs 2 and 3, is capable of performing the steps of the method 100.

[0020] The method 100 includes a first step S102 of positioning said robot in an initial rest position.

[0021] The left part of [Fig.2] illustrates the robot 2 in the rest position, the latter comprising a distal end 2.1, commonly referred to as: robot head 2.1, provided with a junction interface 4 designed to maintain an operational module (not shown) corresponding to a gripper or a specific tool capable of performing, for example, smoothing operations of paint beads, welding, or depositing glue beads, etc.

[0022] In the illustrated configuration, the junction interface 4 allows the mounting of a trajectory generation device 6, which will be referred to as "the device 6" in this description, equipped with means for detecting position in space, which may include, for example, position detection spheres coupled to cameras. It should be noted that the detection means are known and are not the subject of the present invention.

[0023] Advantageously, the junction interface 4 makes it possible to guarantee a common reference frame 8 corresponding to a single Cartesian frame shared by the robot 2 and the device 6 in the mounting position.

[0024] The junction interface 4 also allows the device to be detached from the robot 2 during a trajectory learning step S104 of said robot 2, by manual handling by an operator. In this regard, the device 6 preferably includes a gripping element (not shown) to facilitate its handling by the operator during step S104.

[0025] We can see on the right side of [Fig.2], the device 6 in a position detached from the robot 2, ready to be taken in hand by the operator.

[0026] For this purpose, the junction interface 4 preferably includes a connection, for example by means of a screw, a bolt, a magnetic fastener or a quick-locking system.

[0027] The robot 2 includes a first Cartesian frame 8.1 at the junction interface 4, and the device 6 includes a second Cartesian frame 8.2, said first and second Cartesian frames 8.1, 8.2 form the common reference frame 8 when they are superimposed in the mounting position of the device 6 on the robot 2.

[0028] Fig. 3 illustrates an example of the trajectory 10 generated by the device 6 during the learning step S104 and the generation and transmission step S106 of said trajectory 10 to the robot 2. Said steps S104 and S106 can be carried out simultaneously.

[0029] The trajectory 10 is advantageously generated solely by the operator's manipulation of the device 6 after its detachment from the robot 2. This trajectory 10 comprises position coordinates in three-dimensional space, rotation coordinates about the axes, and the associated velocities. These coordinates are directly recorded in the reference frame 8, corresponding here to the first Cartesian frame 8.1 of the robot 2.

[0030] Advantageously, since the trajectory 10 is relative to the reference frame 8, the corresponding points are directly fed into a storage bay (unit not shown) of the robot 2. In this regard, a computer program can be used, comprising code instructions implementing the method 100 according to the invention. The present invention thus overcomes the problems related to discrepancies between the different reference frames and guarantees a trajectory learned by the robot 2 with increased precision and agility.

[0031] When the trajectory 10 is transmitted to the robot 2, the method 100 further comprises a step S108 in which the operational module can be mounted on the robot 2 at the junction interface 4 and in place of the device 6 in the mounting position illustrated on the left side of [Fig. 2]. Thus, the robot 2 with the operational module will be able to accurately reproduce the trajectory 10 generated by device 6.

Claims

Demands

1. Method (100) for acquiring trajectory points for a robot (2), comprising the following steps: - (S 102) positioning the robot (2) in an initial rest position; - (S 104) learning a trajectory (10) by means of an operator taking hold of a trajectory generation device (6) provided with means for detecting position in space; - (S 106) generation of the trajectory (10) by the trajectory generation device (6) and transmission of said trajectory (10) to the robot (2), in view of a reproduction of said trajectory (10) by the robot(2);characterized in that the trajectory generation device (6) is configured to be mounted on the robot (2) in the initial rest position and to be detached from said robot (2) during the learning step (S102), the mounting of the device (6) on the robot (2) being ensured by means of a junction interface (4) between the robot (2) and said device (6), said junction interface (4) ensuring a common reference frame (8) between the robot (2) and said device (6) when it is mounted on said robot (2).;

2. Method (100) according to claim 1, wherein the trajectory learning step (S 104) comprises a recording of coordinates of points of said trajectory (10) in the reference frame (8).

3. A method (100) according to any one of claims 1 and 2, wherein said method (100) further comprises a step (S 108) of mounting an operational module on the robot (2), replacing the trajectory generation device (6) after the transmission (S 106) of the trajectory (10) to the robot (2), said operational module comprising a Cartesian coordinate system configured to coincide with the reference frame (8) at the junction interface (4).

4. A computer program comprising computer-readable code instructions, characterized in that said program causes the computer to implement the method (100) for acquiring trajectory points for a robot according to any one of claims 1 to 3, when said program is executed by a computer.

5. Unit comprising a computer-readable recording medium, characterized in that the computer program according to claim 4 is recorded on the recording medium.

6. Robot (2), characterized in that it is configured to perform the method (100) of acquiring trajectory points according to any one of claims 1 to 3.

7. Robot (2) according to claim 6, wherein said robot (2) comprises a first Cartesian coordinate system (8.1) disposed at a distal end (2.1) of said robot (2) at the junction interface (4), and the trajectory generation device (6) comprises a second Cartesian coordinate system (8.2), said first and second Cartesian coordinate systems (8.1, 8.2) being superimposed by means of the junction interface (4) when said device (6) is mounted on the robot (2), so as to form the common reference frame (8).

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