JP6807949B2 - Interference avoidance device - Google Patents

Description

The present invention relates to an interference avoidance device that prevents a robot from interfering with peripheral devices.

The interference avoidance device performs an interference check to see if the robot and the peripheral device may interfere with each other depending on whether or not the occupied spaces in which the robot and the peripheral device operate overlap. Then, when it is determined by the interference check at the time of motion planning or motion execution that the robot may interfere with peripheral devices, the interference avoidance device corrects the motion trajectory planned in advance by the program to a different motion trajectory. The robot is controlled with the corrected motion trajectory as the target trajectory. Controlling the robot according to the corrected motion trajectory is called interference avoidance motion. As a result, it is possible to prevent the robot from interfering with other robots or peripheral devices arranged around the robot and causing the robot or peripheral devices to break down, and to prevent the work by the robot from failing. ..

Conventional interference avoidance devices perform interference checks in a Cartesian coordinate system. Alternatively, the conventional interference avoidance device performs an interference check in the configuration space and generates an avoidance trajectory that realizes the interference avoidance operation. Specifically, when interference is found in the space on the Cartesian coordinate system, the interference avoidance device corrects the intermediate trajectory and calculates the avoidance trajectory. Alternatively, the interference avoidance device searches for an avoidance trajectory in the configuration space when interference is found in the configuration space expressed by the joint angle. These methods are based on modifying the robot so that when it is determined that the robot passes through the path where interference occurs, the robot avoids it. In the calculation process for realizing the interference avoidance operation, the amount of calculation processing increases, and it is possible to generate a path that does not interfere reliably at the cost of requiring a certain amount of calculation time or more.

On the other hand, in the conventional interference avoidance device, since the restraint condition is not explicitly set, even if it is satisfied that the robot does not interfere, the work quality such as the work success rate by the robot or the operation speed of the robot is affected. Insufficient consideration of conditions. That is, in the conventional interference avoidance device, whether or not it is the optimum trajectory for executing the work has not been sufficiently examined. The optimum trajectory is the target position and intermediate that comprehensively judge that the robot can perform the work in a short time, can take a trajectory that does not pass through the singular point, and can maximize the work success rate. It is a work track that defines the track. The avoidance trajectory described above can be positioned as a subset of this working track, including the case of interference.

In recent years, especially in the field of automation of assembly work by robots, bin picking for taking out parts from a parts supply box has been actively performed. Bin picking is to grab a specific part from a plurality of randomly stacked parts and carry it to a specific place. In bin picking, the target position is not fixed, and it is necessary to control the operation of the robot according to the position and posture of the parts. The above-mentioned interference check and interference avoidance operations are also required for bin picking.

Patent Document 1 discloses a calculation method that realizes an interference check and an interference avoidance operation in a bin picking operation. In the interference avoidance device disclosed in Patent Document 1, when a robot takes out one part from a plurality of parts arranged in a storage box, a three-dimensional measuring instrument detects a candidate gripping point of the part and grips the part. The position and orientation of the tool part of the robot including the fingertip that grips the part is calculated for the point candidate, and the interference check between the part closest to the part and the tool part in the storage box is performed. Further, the interference avoidance device disclosed in Patent Document 1 changes the target position / posture so that the tool unit does not interfere within an allowable range when it is determined that they are interfering as a result of the interference check.

JP-A-2002-331480

However, in the interference avoidance device disclosed in Patent Document 1, when the robot is corrected to a gripping posture that does not interfere with peripheral devices, the posture is corrected to a posture different from the preset gripping posture, so that interference can be avoided. It has been difficult to suppress a decrease in the success rate of work while avoiding interference because the parts may fail to be gripped only by correcting the posture to be close to the preset gripping posture.

The present invention has been made in view of the above, and an object of the present invention is to obtain an interference avoidance device capable of suppressing a decrease in the success rate of work while avoiding interference.

In order to solve the above-mentioned problems and achieve the object, the interference avoidance device of the present invention is a hand unit that can be opened and closed, which is provided on the arm unit of the robot by inputting measurement data that measures at least the state of peripheral devices. It is an interference avoidance device that prevents the tool unit having the above from interfering with the peripheral device, and is a plurality of devices capable of gripping the tool unit based on the measurement data and the model information of the robot and the peripheral device. It includes a grip point candidate generation unit that calculates grip point candidates, and a trajectory calculation unit that calculates an interference avoidance trajectory in which the tool unit approaches the grip target without interfering with peripheral devices based on a plurality of grip point candidates. The trajectory calculation unit includes a gripping posture generating unit that generates a plurality of gripping posture candidates existing within the allowable posture range without the tool unit interfering with peripheral devices for a plurality of gripping point candidates, and the generated gripping unit. As the target posture of the posture candidate, a plurality of gripping postures capable of generating an approaching trajectory that allows the tool unit to approach the target posture while the spatial motion constraint that the gripping object cannot rotate is generated due to the relationship between the gripping object and the tool unit. Is extracted, and the gripping approach constraint including the hand opening / closing speed and the hand opening / closing time of the hand portion is taken into consideration, and a plurality of orbits having each gripping posture as an end point are generated as the first approach trajectory generation. A second approach trajectory is generated in which the arm portion and the tool portion of the robot approach the unit and the first end point of the first approach trajectory that is far from the gripping target without interfering with peripheral devices. A plurality of first approaching orbits generated by the first approaching orbit generating unit, which can reduce the waiting time for approaching the gripping object in consideration of the gripping approach constraint and the second approaching orbit generating unit. It is characterized in that it includes an avoidance trajectory generation unit that generates an interference avoidance trajectory that connects the first approach trajectory and the second approach trajectory selected from the above.

According to the present invention, it is possible to suppress a decrease in the success rate of work while avoiding interference.

Configuration diagram of a robot system including the interference avoidance device according to the first embodiment of the present invention. Configuration diagram of a production system including the interference avoidance device shown in FIG. 1 and peripheral devices of the interference avoidance device. The figure for demonstrating the gripping posture and the first approach trajectory when the robot hand located above the parts box shown in FIG. 1 approaches an object to be gripped. Configuration diagram of the interference avoidance device according to the first embodiment of the present invention. The figure which shows the example of the definition method of the 1st approach trajectory and the gripping approach start point in the interference avoidance apparatus which concerns on Embodiment 1 of this invention. Configuration diagram of the trajectory calculation unit shown in FIG. The figure for demonstrating the operation of the interference check part shown in FIG. The figure for demonstrating the operation of the gripping posture generating part shown in FIG. The figure for demonstrating the operation of the 1st approach trajectory generating part shown in FIG. The first figure for demonstrating the operation of the 2nd approach trajectory generation part shown in FIG. A second diagram for explaining the operation of the second approach trajectory generating unit shown in FIG. FIG. 3 for explaining the operation of the second approach trajectory generating unit shown in FIG. FIG. 4 for explaining the operation of the second approach trajectory generating unit shown in FIG. The figure for demonstrating the operation of the avoidance trajectory generation part shown in FIG. A flowchart for explaining the operation of the interference avoidance device according to the first embodiment of the present invention. Configuration diagram of the trajectory calculation unit included in the interference avoidance device according to the second embodiment of the present invention. FIG. 1 for explaining the operation of the interference risk evaluation unit shown in FIG. FIG. 2 for explaining the operation of the interference risk evaluation unit shown in FIG. The figure which shows the operation of the robot hand operated by the interference avoidance apparatus which concerns on Embodiment 3 of this invention. Configuration diagram of the trajectory calculation unit included in the interference avoidance device according to the fourth embodiment of the present invention. Hardware configuration diagram of the interference avoidance device according to the first to fourth embodiments of the present invention. The figure which shows the modification of the production system shown in FIG. The figure which shows the configuration example of the interference avoidance apparatus shown in FIG. 22 The figure which shows the 1st modification of the production system shown in FIG. 22 The figure which shows the 2nd modification of the production system shown in FIG. 22 The figure which shows the 3rd modification of the production system shown in FIG. 22 Configuration diagram of the trajectory calculation unit included in the interference avoidance device according to the fifth embodiment of the present invention. Configuration diagram of the trajectory calculation unit included in the interference avoidance device according to the sixth embodiment of the present invention. The figure for demonstrating the operation by the trajectory calculation part shown in FIG. A flowchart for explaining the operation by the trajectory calculation unit shown in FIG. 28. Configuration diagram of the trajectory calculation unit included in the interference avoidance device according to the seventh embodiment of the present invention.

Hereinafter, the interference avoidance device according to the embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to this embodiment.

Embodiment 1.
FIG. 1 is a configuration diagram of a robot system provided with an interference avoidance device according to a first embodiment of the present invention. The robot system 100 shown in FIG. 1 includes a measuring unit 1, an interference avoidance device 2, a robot control device 3, and a robot. 4 is provided. FIG. 2 is a configuration diagram of a production system including the interference avoidance device shown in FIG. 1 and peripheral devices of the interference avoidance device. The production system 200 shown in FIG. 2 has information in addition to the robot system 100 shown in FIG. It includes an integrated terminal 5, a conveyor control device 6, a processing machine control device 7, and a robot control device 8.

As shown in FIG. 2, the information integration terminal 5 is connected to the robot control device 3. The information integrated terminal 5 is a device that collects and distributes information from a device such as a server, an edge server, or a PLC (Programmable Logic Controller) on a cloud (not shown). A plurality of peripheral devices are connected to the information integrated terminal 5. Examples of the plurality of peripheral devices include a conveyor control device 6, a processing machine control device 7, and a robot control device 8. Information output from each of the conveyor control device 6, the processing machine control device 7, and the robot control device 8 is transmitted to the information integration terminal 5, and the information transmitted to the information integration terminal 5 is transmitted to the information integration terminal 5 via the robot control device 3. Is transmitted to the interference avoidance device 2. In the interference avoidance device 2, the latest information transmitted from the peripheral device and the measurement data 1a measured by the measurement unit 1 are used at the time of the interference check described later. In FIG. 2, the information integrated terminal 5 is connected to the interference avoiding device 2 via the robot control device 3, but the information integrated terminal 5 may be directly connected to the interference avoiding device 2.

The robot 4 shown in FIG. 2 is an articulated robot with 6 degrees of freedom. The robot 4 includes an arm portion 41 that constitutes a robot main body portion manufactured by a robot maker, and a tool portion 42 provided at the tip of the arm portion 41. The tool unit 42 includes a hand unit 43, a jig 44 attached to the hand unit 43, and a measuring unit 1 attached to the jig 44.

The measuring unit 1 may be any measuring device for measuring the position and orientation of the part 9a in the parts box 9, and the measuring unit 1 includes a camera that images the parts 9a in the parts box 9 and a hand unit 43. Examples thereof include a vision sensor, which is an image sensor that captures images of and peripheral devices thereof, a laser displacement meter, and a non-contact sensor. The measuring unit 1 provided on the hand unit 43 via the jig 44 moves together with the hand unit 43 so as not to interfere with the parts box 9. Here, the measurement unit 1 will be described with the configuration of a "hand eye" provided in the tool unit, but as a means for measuring the peripheral device, a method of fixing the peripheral device at a position where it can be observed from a bird's-eye view is also implemented in the same manner. be able to.

FIG. 2 shows a bin picking operation in which the robot takes out one component 9a from a plurality of components 9a arranged in the component box 9 as an example of the operation by the robot 4. However, the work by the robot 4 using the interference avoidance device 2 according to the first embodiment is not limited to the bin picking work, and may be a material handling work, a kitting work, or an assembly work. The reason why the work by the robot 4 is not limited in this way is that when the operation of the robot 4 is changed according to the state of the component 9a, the robot 4 basically performs the same processing. The operations of the interference avoidance device 2, the robot control device 3, and the robot 4 during the bin picking operation will be described below.

The robot 4 first moves to a position before the bin picking operation according to a program executed by the robot control device 3. Next, the interference avoidance device 2 measures the three-dimensional position and the three-dimensional posture of the component 9a by the measuring unit 1. Hereinafter, the three-dimensional position and the three-dimensional posture of the component 9a may be referred to as the three-dimensional position and posture of the component 9a.

The interference avoidance device 2 does not use the measurement data 1a measured by the measurement unit 1 as it is, but uses it after converting it into a three-dimensional position and orientation holding information on a three-dimensional point cloud, line, surface, and color. .. As a method of measuring the three-dimensional position / orientation of the component 9a from the measurement data 1a, there are a method of measuring the three-dimensional position / orientation based on the distance to the target point measured by using a laser, infrared rays or sound waves, and a method of measuring the three-dimensional position / orientation with a stereo camera. An example can be given as a method of measuring the three-dimensional position and orientation. The measuring unit 1 may be any measuring device that can reproduce the three-dimensional position / orientation information of the picking target in the interference avoidance device 2, and is not limited to the above-mentioned camera, vision sensor, laser displacement meter, and non-contact sensor. .. Further, the measurement target may include not only the component 9a but also the component box 9 and the peripheral device, and the interference avoidance device 2 uses the measurement data 1a obtained by measuring the component 9a, the component box 9 and the peripheral device to check the interference. You may use it for.

Next, a method of determining the picking target will be described using the measurement data 1a. In determining the picking target, it is common to execute a process of selecting a plurality of candidate points from the measurement data 1a and a process of selecting one candidate point from the plurality of selected candidate points. The former process, that is, the means for selecting a plurality of candidate points from the measurement data 1a, is roughly divided into two types.

The first means of selecting a plurality of candidate points is to store a drawing model or a component model such as a 3D computer-aided design (CAD) in the interference avoidance device 2 in advance, or to perform a three-dimensional position and orientation of a picking target. This is a method of estimating the most probable posture of the picking target by storing the reference data of the information in the interference avoidance device 2 and collating the measured measurement data 1a with the component model or the reference data. Hereinafter, this estimation method will be referred to as model matching.

The interference avoidance device 2 uses the estimated posture of the picking target to determine the gripping point at which the hand portion 43 grips the component 9a from the predetermined positional relationship between the picking target and the tool portion 42. Here, the positional relationship between the picking target and the tool unit 42, which is predetermined, may be given by the user in advance by teaching work, or may be determined offline by the user from the position of the center of gravity of the picking target and the ease of holding. is there.

The second means of selecting a plurality of candidate points is a method that does not require model matching, and will be referred to as modelless matching below. In modelless matching, a part model to be picked is not required, and a space that satisfies the condition that the hand portion 43 can easily grip the part 9a is searched from the measured feature quantities such as point cloud, line, and surface, and the gripping point is determined. It is determined. The condition for easy gripping is a portion of the point cloud that can be included in the gripping region when the space provided in the hand portion 43 that can be sandwiched between the fingertips when opening and closing the fingers is set as the gripping region. Since any part that can be included in the gripping area can be generated, when the number of gripping points is limited, the part 9a can be gripped stably with respect to the opening / closing direction of the finger in the gripping area. The number of point clouds included in the region can be reduced by adding constraints. Examples of the constraint condition include a case where the hand portion 43 faces and is parallel to the finger provided, and a case where there is no obstacle over a depth D [mm] in the direction in which the hand portion 43 includes the finger.

Unlike model matching, modelless matching has a problem that the boundary between a plurality of objects to be gripped becomes ambiguous. Therefore, in the point cloud information, the objects to be gripped are often grouped at the boundaries of a plurality of objects by a process called clustering, which makes it possible to distinguish between the multiple objects and calculate a guideline for the position of the center of gravity. Become.

Next, the above-mentioned "process of selecting one candidate point from a plurality of selected candidate points" will be described. In general, as a rule for selecting one candidate point, it can be exemplified that an index that is easy to grip is provided and a part that is easiest to grip is selected. Examples of indicators that are easy to grasp include indicators that are statistically databased from past achievements and indicators that are determined based on rules that are derived in consideration of physical laws such as the balance of gravity and force and the position of the center of gravity. ..

As a simple index for selecting one candidate point from a plurality of selected candidate points, when one component 9a is taken out from the component 9a group arranged in the component box 9, it is arranged above the component 9a group. It is conceivable to use what is done as a candidate point. This is because gripping the component 9a located above the component 9a group is less likely to break the component 9a group than the component 9a arranged below the component 9a group, and as a result, the picking target is used. This is because it is possible to reduce the factor of failing to remove the component 9a when gripping the component 9a. It is also possible to statistically determine the priority from a large amount of execution data. That is, when the height and direction in which gripping is likely to be successful are known, the gripping point can be preferentially selected.

The interference avoidance device 2 performs an interference check on one selected candidate point to see if the tool unit 42 may interfere with the parts box 9 or peripheral devices. Here, the candidate point indicates "coordinate point information in which the tool unit grips the part", and is represented by, for example, the position (X, Y, Z) of the tool unit and the posture (for example, a set of three angles representing the posture). Euler angle representation) information is included. That is, in the interference avoidance device 2, when the tool unit 42 moves to the selected candidate point, whether or not the tool unit 42 interferes with the parts box 9 and whether or not the tool unit 42 interferes with the peripheral device described above. Before the bin picking operation. Specifically, the interference avoidance device 2 confirms whether or not the tool unit 42 interferes with the parts box 9 or the peripheral device in the area occupied by the tool unit 42 at the gripping point, or the moving direction of the tool unit 42. It is confirmed whether or not the tool unit 42 interferes with the parts box 9 or the peripheral device in the area including the track extended to.

Generally, the parts box 9, the parts 9a, the arm 41 and the tool 42 are modeled. The model is represented by the occupied volume in the three-dimensional space and the occupied area in the two-dimensional plane. As modeling, there are cases where the detailed shapes of the parts box 9, parts 9a, arm 41 and tool 42 are modeled according to 3D-CAD, and simple cases called primitives such as polyhedra, rectangular parallelepipeds, cylinders or spheres. The case of modeling with a model can be illustrated. The former is not suitable for real-time calculation because the calculation cost is high, although the judgment accuracy of the interference check is improved. The latter is suitable for real-time calculation because the calculation cost is low, but the calculation cost increases as the number of model judgments increases, and there is a possibility of erroneous judgment due to low judgment accuracy, and the judgment accuracy is low, so it is excessive. A safe decision may be made.

When there is a possibility of interference in the interference check determination, the interference avoidance device 2 has a fingertip posture in the direction in which the tool unit 42 moves away from the parts box 9 based on the allowable posture range which is the allowable range of the robot posture set in advance. To change. As a result, the gripping point can be determined while avoiding the tool portion 42 interfering with the parts box 9. As shown in FIG. 2, since the plurality of parts 9a arranged in the parts box 9 have different positions and orientations, the above-mentioned allowable posture range changes for each picking target, but generally, the postures for a certain angle are different. Under the constraint that it may change, a posture that does not interfere is searched for.

In this way, the interference avoidance device 2 has a function of generating picking candidates and an interference check function, and executes a picking operation when there is no possibility that the tool unit 42 interferes with the parts box 9 or peripheral devices. On the other hand, when there is a possibility of interference, the interference avoidance device 2 corrects the posture at the gripping point based on the above-mentioned allowable posture range, and performs an interference check again for this.

Here, when a posture in which interference does not occur is searched for from a gripping point where gripping is easy to succeed, the posture is defined as a new gripping point, and the tool unit 42 is moved to the gripping point to grip, conventional interference avoidance is avoided. The device raises the following two issues.

The first problem is that the conventional interference avoidance device lowers the gripping success rate because the approaching direction at the time of gripping is not considered as a required trajectory in the conventional interference avoidance device.

When the picking component 9a has a protrusion, the direction in which the tool portion 42 approaches the gripping point of the component 9a and the posture of the tool portion 42 with respect to the component 9a, that is, the relative position of the tool portion 42, match as a point. If not only the positional relationship at the time of picking but also the trajectory leading to gripping is not taken into consideration, the gripping success rate may be unnecessarily lowered. That is, if there are no restrictions on the direction in which the tool unit 42 is moved, the gripping success rate is unlikely to decrease, but the tool unit 42 may interfere with the parts box 9 or peripheral devices in the direction in which the tool unit 42 is moved. There is a high possibility that the gripping success rate will decrease when there is a possibility that the component 9a will move if the gripping point is not reached from a specific direction.

The cases where the gripping success rate is likely to decrease are the case where the shape of the parts box 9 is asymmetrical or the shape of the peripheral device is asymmetrical so that the tool portion 42 easily interferes at a specific position, and the arm portion. Examples thereof include a case where the finger shape of the 41 is not a flat plate shape but a bent L-shape, a case where the end face of the part 9a is bent, and a case where the shape of the part 9a is asymmetric and the allowable posture range is narrow.

At this time, the posture of the tool portion 42 at the gripping point of the component 9a may differ from the posture of the tool portion 42 approaching the gripping point of the component 9a. Checking for interference with respect to the gripping posture in the direction in which the tool unit 42 moves in a certain direction is not general because there is no consideration for the gripping trajectory. On the other hand, when the posture of the tool unit 42 is rotated within an allowable range in order to avoid interference, it is possible to evaluate how much the gripping success rate deteriorates when performing an interference check, although it can be performed for the gripping point. It cannot be executed for the gripping trajectory.

The second issue is that in considering a trajectory that avoids interference while increasing the success rate of gripping, a method for determining one gripping point in a form including whether or not there is a path that does not interfere has been conventionally used. This is a point that is not disclosed in the technology. In the conventional interference check, only the gripping point is focused on. Therefore, the problem is to calculate the gripping point having a high gripping success rate and no possibility of interference as one position, and the movement to reach the gripping point is when the part 9a is gripped. The tool portion 42 is lowered from above the parts box 9 in the same posture as the posture of the tool portion 42. However, as the model becomes more detailed, the method of checking only the presence or absence of simple interference at the gripping point has many restrictions and fewer solutions when viewed in the trajectory leading to gripping, and the gripping success rate is reduced. It can be significantly reduced.

FIG. 3 is a diagram for explaining a gripping posture and a first approaching trajectory when a robot hand located above the parts box shown in FIG. 1 approaches an object to be gripped. The first approach trajectory is a trajectory in which the tool unit of the robot hand can approach the grip target in the generated gripping posture without shifting the grip target, and is also called a grip approach trajectory. The parts box 9 shown in FIG. 3 is horizontal with a flat bottom surface portion 91 in contact with the floor surface 50 and one of the end portions of the bottom surface portion 91 in the horizontal direction extending vertically from one end portion 92a. Of the ends of the bottom surface 91 in the direction, the other measuring surface portion 92b extending vertically from the other end, and the upper surface portion extending horizontally from the upper end of the end of the measuring surface portion 92b in the vertical direction. It is equipped with 93.

The horizontal length of the upper surface portion 93 is shorter than the horizontal length of the bottom surface portion 91. Therefore, an opening 94 is formed above the bottom surface portion 91 that constitutes the parts box 9. The opening 94 is provided between the end of the upper surface portion 93 on the measuring surface portion 92a side and the upper end of the measuring surface portion 92a. As described above, the parts box 9 shown in FIG. 3 has a shape in which the upper left end portion thereof protrudes inside the parts box 9.

In FIG. 3, three hand portions 43A, 43B, and 43C are shown for convenience in order to explain the gripping posture of the hand portion 43. The hand portions 43A, 43B, and 43C all correspond to the hand portion 43 shown in FIG. The hand portion 43A corresponds to the hand portion 43 in the gripping posture A, the hand portion 43B corresponds to the hand portion 43 in the gripping posture B, and the hand portion 43C corresponds to the hand portion 43 in the gripping posture C. Corresponds to.

A plurality of parts 9a are arranged in the parts box 9, and the part 9a1 arranged at the top of the plurality of parts 9a is an object to be gripped by the hand portions 43A, 43B, 43C. The component 9a1 has an L-shape including a longitudinal piece 9a11 and a short piece 9a12 extending in a direction perpendicular to the end of the longitudinal piece 9a11. A plurality of parts 9a other than the parts 9a1 also have the same shape as the parts 9a1. In the component 9a1, the end portion of the longitudinal piece 9a11 faces the measuring surface portion 92a, and the bottom portion of the longitudinal piece 9a11 is in contact with the component 9a existing below the component 9a1. Further, in the component 9a1, the end portion of the short piece 9a12 is located on the side opposite to the component 9a side existing below the component 9a1.

The hand portion 43A in the gripping posture A is located closer to the upper surface portion 93 than the hand portions 43B and 43C in the gripping postures B and C. The solid line movement locus A1 represents the movement locus of the tip portion of the hand portion 43A. In FIG. 3, the hand portion 43A moving on the movement locus A1 approaches the component 9a1 so as to grip the short hand piece 9a12 of the component 9a1. However, the hand unit 43A and the measurement unit 1 that move on the movement locus A1 may interfere with the upper surface portion 93.

Since the hand portion 43C can grip the longitudinal piece 9a11 of the component 9a1, the gripping posture C is a desirable posture for increasing the gripping success rate of the component 9a1, but is arranged at a position overlapping the measuring surface portion 92a. , Interferes with the measuring surface portion 92a.

The dotted line movement locus B1 represents the movement locus of the tip portion of the hand portion 43B. In FIG. 3, the hand portion 43B moving on the movement locus B1 approaches the component 9a1 so as to grip the short hand piece 9a12 of the component 9a1. The hand portion 43B and the measuring portion 1 that approach the component 9a1 on the moving locus B1 do not interfere with the upper surface portion 93 and the measuring surface portion 92a. However, the gripping success rate when the hand portion 43B moving on the moving locus B1 takes out the component 9a1 is lower than the gripping success rate when the hand portion 43A moving on the moving locus A1 takes out the component 9a1. This is because the hand portion 43A simultaneously grips the short hand portion 9a12 and the longitudinal piece 9a11 of the component 9a1 as compared with the hand portion 43B that grips a part of the short hand piece 9a12 of the component 9a1.

As described above, in order to increase the gripping success rate when the component 9a1 is taken out from the plurality of components 9a arranged in the component box 9, the gripping posture A and the gripping posture C are preferable to the gripping posture B. However, since the gripping posture C is determined to have interference by the interference check, it is excluded from the gripping point candidates, and the gripping posture A and the gripping posture B remain as the gripping point candidates. Regarding the presence or absence of interference, it is desirable to select the gripping posture B as the gripping point candidate, considering that the first approaching trajectory has the same posture as the gripping point candidate. However, since the gripping posture B is a posture in which emphasis is placed on not interfering with each other, it is important to consider the gripping success rate and the presence or absence of interference in a well-balanced manner in order to increase the gripping success rate. Therefore, how to grasp the condition that there is no interference is an important point.

The interference avoidance device 2 according to the first embodiment defines a first approach trajectory for each tool unit 42 used for gripping so that the gripping posture A shown in FIG. 3 is selected, and the tool unit 42 may interfere. It is effective when a second approaching orbit that can avoid interference is searched for by generating a first approaching orbit without any interference and connecting the starting point of the generated first approaching orbit and the starting point of the picking operation, and having this solution. A gripping point candidate that is a gripping posture is selected, and the selected tracks are connected to form an interference avoidance track A2. The second approach trajectory is a trajectory in which the arm portion and the tool portion of the robot approach the gripping object from the end point (starting point) of the first approach trajectory without interfering with peripheral devices.

In the conventional interference avoidance device, only the gripping point is determined without considering the movement locus of the tool portion reaching the gripping point of the component, so that the gripping posture A shown in FIG. 3 is not selected. On the other hand, in the interference avoidance device 2 according to the first embodiment, the gripping posture A is selected.

Hereinafter, the configuration and processing contents of the interference avoidance device 2 according to the first embodiment will be specifically described. First, an outline of the configuration of the interference avoidance device 2 according to the first embodiment will be described with reference to FIG. FIG. 4 is a configuration diagram of the interference avoidance device according to the first embodiment of the present invention.

The interference avoidance device 2 shown in FIG. 4 includes measurement data 1a output from the measurement unit 1, model information 3a input via the robot control device 3, and a robot program before and after gripping output from the robot control device 3. Based on 3b and the setting information 3c input via the robot control device 3, the interference avoidance trajectory 2a is generated and output.

The model information 3a is data relating to the arm portion 41, the tool portion 42, the peripheral device, and the parts box 9. Specifically, the model information 3a is each geometric information expressed in 3D-CAD as information for defining the occupied area of the arm portion 41, the tool portion 42, the peripheral device, and the parts box 9 in the three-dimensional space. Or, it is expressed as a primitive including each of the arm portion 41, the tool portion 42, the peripheral device, and the parts box 9. As the primitive, a sphere and its center position can be exemplified. By using the model information 3a, it is possible to confirm the presence or absence of interference between the arm portion 41, the tool portion 42, the peripheral device and the parts box 9, and also the arm portion 41, the tool portion 42, the peripheral device and the parts box 9. It is possible to calculate the relative distance between the two.

The robot program 3b before and after gripping is a robot language program stored in the robot control device 3 shown in FIG. The robot program 3b may be any information that defines the position related to the robot movement, and is not limited to the information stored in the robot control device 3, but may be information that defines the position related to the robot movement stored in a personal computer (not shown). ..

The setting information 3c is information for setting an allowable posture range, which is a preset allowable range of the robot posture.

The interference avoidance device 2 interferes based on the grip point candidate generation unit 10 that calculates a plurality of grip point candidates 10a based on the measurement data 1a, the model information 3a, and the robot program 3b, and the plurality of grip point candidates 10a and the setting information 3c. The orbit calculation unit 11 for calculating the avoidance orbit 2a is provided.

The gripping point candidate 10a includes gripping point candidate information and gripping constraint information. The grip restraint information determines the positional relationship between the tool unit 42 and the object to be gripped in advance in order to succeed in gripping, and a position separated from the object to be gripped by a certain distance with the point at which the positional relationship is achieved as the target point. The restraint condition when the tool unit 42 is brought close to the object to be gripped is shown. A position separated by a certain distance from the object to be gripped is a position at which the gripping approach is started, and a position 10 mm away from the gripping point candidate in the Z-axis direction of the tool coordinate system can be exemplified. The tool coordinate system indicates a coordinate system to be set in the tool unit 42. The Z-axis direction of the tool coordinate system is set on an axis that passes through the center point of the stroke of the portion that opens and closes the fingertip of the hand portion 43 and is parallel to the fingertip direction of the hand portion 43. The X-axis and Y-axis directions of the tool coordinate system are determined for ease of use by the user.

In the grip restraint, first, a target position-posture relationship is determined with respect to the tool portion 42 and the object to be gripped. When gripping an object, the most desirable gripping posture is defined in advance as the positional relationship between the tool unit 42 and the object to be gripped. The most desirable gripping posture can be determined based on a database of operations for gripping an object to be gripped by using the tool unit 42. For the database, the results derived from the actual experimental results may be used, or the results of the physical simulation or the offline simulation may be used.

There is an allowable posture error in the position-posture relationship between the tool unit 42 and the object to be gripped, and the statistical average value and the median value of the position-posture relationship in which the grip is successful can be defined. That is, the predetermined desirable position-posture relationship between the tool unit 42 and the object to be gripped is predetermined as a typical position-posture relationship in which gripping is successful.

The operation of the interference avoidance device 2 will be described below. In order to calculate the position or trajectory for the robot 4 to grip the object, the measuring unit 1 measures the state of the object to be gripped. As the state of the object, the position and orientation of the component 9a can be exemplified. From the information obtained by measuring the state of the object, the position / orientation information of the object to be gripped with respect to the robot coordinate system can be obtained. The robot coordinate system is a coordinate system based on the robot 4, and is a coordinate system used when controlling the position of the robot 4. Normally, the Z axis is defined in the direction perpendicular to the installation surface of the robot 4, the origin is at the point where the axis of the first joint and the installation surface intersect, and the X axis is defined at the center position of the movable range of the first joint. To.

In the gripping point candidate generation unit 10, image processing technology and position estimation processing are generally performed in order to acquire the position / orientation information of the object to be gripped. In the gripping point candidate generation unit 10, the distance information between the measurement unit 1 and the measurement target, the point cloud information obtained by plotting the distance information three-dimensionally, and the texture information of the surface of the measurement target are input in advance. SLAM (Simultaneus Localization And Mapping) is applied as position estimation processing based on matching with the prepared model or the relationship between acquired information at different times, and model matching technology is used as image processing technology to grasp the object to be grasped. Position and orientation information is calculated.

The gripping point candidate generation unit 10 is gripped by the robot by inputting the calculated position / posture robot_T_work of the object to be gripped from the robot coordinate system and the target position / posture tool_T_work of the tool unit 42 and the object to be gripped determined in advance. The target position / posture robot_T_tool of the tool unit 42 for realizing the above is determined.

Here, the expression i_T_j indicates the homogeneous transformation matrix T from the i-coordinate system to the j-coordinate system. The homogeneous transformation matrix T is a 3-by-3 rotation matrix R representing the relationship between the i-coordinate system and the j-coordinate system on the X-axis, Y-axis, and Z-axis, and the origin of the j-coordinate system as seen from the i-coordinate system. It is a 4-by-4 matrix expressed by the following equation (1) from the translation vector p (= (x, y, z)) of three elements representing the positional relationship of. However, 0 in the following equation (1) represents a zero matrix consisting of 0s in 1 row and 3 columns.
T = (R p
0 1) ・ ・ ・ (1)
The rotation matrix R is generally a three-row, three-column matrix consisting of R = (R11, R12, R13; R21, R22, R23; R31, R32, R33), and the relative rotation is represented by a matrix. Further, p is a vector of 3 rows and 1 column, and indicates a position vector of a target point as viewed from a certain reference coordinate system.

The gripping point candidate generation unit 10 determines the target position Pgg of the robot fingertip position for the gripping operation by calculating the target position / posture robot_T_tool using the homogeneous transformation matrix i_T_j. The target position Pgg replaces the target position / posture robot_T_tool of the tool unit 42 with the expression of the robot command value. As the representation of the robot command value, translation positions X, Y, Z and rotation amounts A, B, C around each axis of X, Y, Z can be exemplified. The target position / posture robot_T_tool can be obtained by the following equation (2).
robot_T_tool = robot_T_work * (tool_T_work) ^ -1 ... (2)

The target position Pgg of the robot fingertip position has a plurality of point candidates when there are various desirable relationships between the object to be gripped and the tool unit 42. Therefore, in the following, the candidate points of the plurality of target positions Pgg are expressed as the gripping point candidate Pgg (i).

The gripping point candidate generation unit 10 calculates a position separated from the gripping point candidate Pgg (i) by a certain distance based on the target position / posture relationship between the tool unit 42 and the object to be gripped, and determines the position as the gripping approach start point. When Psg (i) is used, the interpolation method from the gripping approach start point Psg (i) for each gripping point candidate to the gripping point candidate Pgg (i) and the respective positions and postures are stored. That is, when focusing only on gripping, the first approaching trajectory is a trajectory that describes the change (orbit) in the positional relationship between the object to be gripped and the tool portion 42 in order to succeed in gripping. The first approaching trajectory is an orbit from the gripping approach start point Psg (i) to the gripping point candidate Pgg (i). The gripping approach start point Psg (i) is a point at which the gripping operation is started.

In the gripping operation, the moving direction and movement are performed in order to avoid a gripping failure by the tool unit 42 touching the object to be gripped or the peripheral device before reaching the target position and orientation of the tool unit 42 and the object to be gripped. It shall include only gripping using the tool portion 42 with a limited amount. Here, in the trajectory until the tool unit 42 reaches the target position / posture of the object to be gripped, the trajectory of the tool unit 42 that is a certain distance away from the target position / posture of the object to be gripped is a success or failure of gripping. As a movement other than the gripping motion, it is treated separately as a second approaching trajectory. That is, the second approach trajectory can select a control method or operation setting different from that of the first approach trajectory. For example, in order to increase the operating speed, the speed of the second approaching trajectory can be set higher than that of the first approaching trajectory. Alternatively, for the second approaching trajectory, joint interpolation may be selected only during the second approaching trajectory to improve the operating speed. Here, joint interpolation is an interpolation method in which the angle of a target point is set as a target angle for each motor axis and controlled. In joint interpolation, the hand trajectory cannot be controlled to the designed trajectory, but the restrictions on controlling each axis motor are reduced, and the motor can be moved at high speed. The second approach trajectory will be described later.

Positional relationships, distances and attitude changes related to the first approach trajectory can also be obtained from learnedly acquired positional relationships using a database of successful or unsuccessful gripping, and geometric constraint relationships. A similar relationship may be derived analytically from. That is, the method of determining the gripping approach start point Psg may be other than the arm direction of the tool unit 42. Specifically, while drawing an arc having a radius R with the grip point candidate Pgg (i) as an input and the grip point candidate Pgg (i) as the end point of the arc, a position separated from the end point by a certain distance is calculated. The position can also be referred to as the gripping approach start point Psg. Further, when the surface of the object to be gripped has irregularities, the hand portion so as to avoid the uneven portions on the surface of the object by the time the fingertip of the hand portion 43 and the target position / posture relationship for gripping the object to be gripped are reached. In some cases, a constant trajectory is given to move 43.

The gripping point candidate Pgg (i), the gripping approach start point Psg, and the first approaching trajectory will be described with reference to FIG. FIG. 5 is a diagram showing an example of a method of defining a first approach trajectory and a gripping approach start point in the interference avoidance device according to the first embodiment of the present invention. As shown in FIG. 5, the gripping approach start point Psg corresponds to the operating point to be passed by the fingertip of the hand portion 43. The gripping point candidate Pgg (i) is used as the end point of the first approach trajectory, and the fingertip of the hand portion 43 is obtained as the start point of the first approach trajectory 13 away from the component 9a while avoiding interference with the convex portion 12 of the component 9a. be able to. Here, the first approaching trajectory can also be used for an orbit that moves so as to be taken out after being approached and gripped. In particular, when considering the time of taking out, it is possible to specify the first approaching trajectory in which a point away from the gripping posture is specified at a position where the work can be taken out by moving the shortest distance as a starting point. For example, the minimum amount of movement required for successful lifting after gripping a part with sufficient distance from other parts can be defined as the shortest distance movement.

The database on the success or failure of grasping can be realized in both the case where the trial is performed using the physical simulation and the case where the experiment is actually performed using the actual machine. The priority of the gripping point candidate for the work is determined in advance based on the priority as described above. As the priority, it can be exemplified that the gripping posture having a high success rate is selected based on the past database, or the part 9a arranged on the upper side of the parts box 9 is preferentially selected.

The trajectory calculation unit 11 selects a gripping point in the gripping posture generating unit using the setting information 3c and the plurality of gripping point candidates 10a, and generates a first approaching trajectory that satisfies the gripping constraint for the selected gripping point. To do. Further, a trajectory that does not interfere with the box or the like is generated as the second approach trajectory by connecting to the gripping approach start point that is the starting point of the first approach trajectory. Finally, the interference avoidance orbit is calculated by connecting the first approach orbit and the second approach orbit, and is output as the interference avoidance orbit 2a. The conventional interference avoidance device only calculates the gripping point candidate without calculating the interference avoidance trajectory, but in the interference avoidance device 2 according to the first embodiment, in addition to the gripping point candidate, the gripping point candidate 10a and the second gripping point candidate Using the approaching orbit, the entire interference avoidance orbit is calculated by combining these.

Hereinafter, the configuration and operation of the trajectory calculation unit 11 for generating the interference avoidance trajectory 2a will be described.

6 is a configuration diagram of the trajectory calculation unit shown in FIG. 4, FIG. 7 is a diagram for explaining the operation of the interference check unit shown in FIG. 6, and FIG. 8 is an operation of the gripping posture generating unit shown in FIG. 9 is a diagram for explaining the operation of the first approach trajectory generation unit shown in FIG. 6, and FIGS. 10 to 13 are diagrams for explaining the operation of the first approach trajectory generation unit shown in FIG. It is the first to fourth figures for demonstrating the operation of a part. FIG. 14 is a diagram for explaining the operation of the avoidance trajectory generation unit shown in FIG.

The trajectory calculation unit 11 shown in FIG. 6 includes a gripping posture generation unit 21, a first approach trajectory generation unit 22, a second approach trajectory generation unit 23, an avoidance trajectory generation unit 24, and an interference check unit 25.

The gripping posture generation unit 21 generates an effective gripping posture 21a that has no possibility of interference as a gripping point candidate after checking for interference with peripheral devices including the parts box 9 from the plurality of gripping point candidates 10a. As shown in FIG. 8, the plurality of gripping point candidates 10a include a plurality of gripping postures A, B, and C, and the postures that the tool unit 42 can take are among these plurality of gripping postures A, B, and C. , It is generated through the processing in the interference check unit 25. The gripping point candidate is referred to as a candidate point for a robot tool unit having a different position or posture.

The interference check unit 25 shown in FIG. 6 determines the relative distance between the robot hand model 101 and the peripheral device model 102, for example, for the robot hand model 101 and the peripheral device model 102 shown in FIG. 7 to be checked for interference. It is calculated and it is determined whether or not the relative distance is equal to or less than the reference value. Further, the interference check unit 25 calculates the relative distance between the tool model 103 and the peripheral device model 102, for example, for the robot hand model 101 and the peripheral device model 102 shown in FIG. 7 to be subjected to the interference check. , Determine whether the relative distance is less than or equal to the reference value. When performing the interference check, the interference check unit 25 inputs the geometric shape information and the position / orientation information of the model as the model information, determines whether or not there is interference, and the calculated relative distance between the models. The interference check judgment information including and is output. Geometric shape information is information about attributes, dimensions, and so on. Information about attributes is information such as shape characteristics, primitive shapes, polyhedra, and free shapes. Primitive shapes are shapes such as spheres, rectangular parallelepipeds, cylinders, and cones. The polyhedron is a polyhedron surrounded by a triangular patch surface formatted by 3D-CAD (three Dimensional Computer Aided Design). A free shape is a point cloud set defined by a point cloud. The dimensions are the radius R if it is a sphere, and the radius R and the length L if it is a cylinder. The interference check unit 25 needs to check the generated trajectory at each time. The interference check unit 25 inputs model information for each time to the orbit and calculates whether or not there is interference in the entire orbit. In order to reduce the calculation cost, there is a method of evaluating only a few typical postures among the starting point and the ending point. In addition, in order to reduce the calculation cost, a geometric model in which the robot arm and the robot hand model at the orbit start point and the robot arm and the robot hand model at the end of the orbit are spatially interpolated, for example, a polyhedron is generated. There is a method to evaluate the presence or absence of interference.

The first approach trajectory generating unit 22 shown in FIG. 6 applies the gripping constraint corresponding to the effective gripping posture 21a generated by the gripping posture generating unit 21 to generate the effective first approaching trajectory 22a. The interference check unit 25 performs an interference check on the effective first approach trajectory 22a. In FIG. 9, the effective gripping postures A'and B'generated by the gripping posture generating unit 21, the first approaching trajectory A1'considering the approach constraint on the effective gripping posture A', and the effective gripping posture B'are shown. The first approach trajectory B1'in consideration of the approach constraint is shown. In this case, in order to reliably grip the component 9a1 to be gripped, the tool portion 42 is started to approach from a position separated from the component 9a1 by a certain distance, and the tip of the tool portion 42 slips under the component 9a1. It is necessary to carry out such an operation.

As shown in FIG. 9, the tool unit 42 operating in the first approach trajectory A1'may interfere with the parts box 9. Therefore, it is desirable not to generate the first approach trajectory A1'corresponding to the effective gripping posture A', but to generate the first approach trajectory B1'corresponding to the effective gripping posture B'. Further, since the gripping posture generating unit 21 is provided in front of the first approaching orbit generating unit 22, the first approaching orbit generating unit 22 calculates an effective first approaching orbit 22a for all gripping point candidates. There is no need to do this, and calculation efficiency is improved.

Hereinafter, the gripping constraint on the tool unit 42 side with respect to the gripping point candidate will be described. The gripping constraint defines the moving trajectory of the tool unit 42 to the gripping point candidate introduced in order to increase the success rate of the work. When the target position / posture of the tool unit 42 with respect to the gripping point is changed, the target position / posture of the tool unit 42 is also affected by variable conditions such as the gripping form, mechanism, and material of the fingertip of the hand unit 43, and thus the production system 200 is configured. The method of increasing the gripping success rate differs depending on the mechanism to be used. When generating the interference avoidance trajectory, the second approach trajectory generating unit 23 considers the constraint condition regarding the fingertip of the hand unit 43, and considers not only the gripping posture but also the intermediate trajectory related to the grip as the constraint condition. The intermediate orbit is an orbit connecting the gripping approach start point Psg, which is the starting point of the effective first approach orbit, and the start point of the picking operation. The starting point of the picking operation is selected to be above a shelf or box (a part of the surrounding environment) containing the target parts, or a point sufficiently separated from the arm or hand so that the surrounding environment does not interfere with each other.

As shown in FIG. 10, when the open / close gripper type hand portion 43 is used, if the method of closing the hand portion 43 is an air type, the gripping speed is determined by the air pressure, and the factory where the hand portion 43 is installed. Since the pressure of the air used in is often a constant value, the gripping speed is a constant value. At this time, if the gripping speed is too high, there is a risk that parts will fall from the hand portion 43. In order to prevent such a risk, the idea of gripping point candidates such that the hand portion 43 touches the lower side of the part 9a1 and then touches the upper side of the part 9a1 changes depending on the configuration of the hand portion 43. Note that FIG. 10 shows an ideal approach direction 14 in which the hand portion 43 approaches the component 9a1 and an allowable approach direction 15 in which the hand portion 43 can grip the component 9a1.

In FIG. 11, instead of the opening / closing gripper type hand portion 43 shown in FIG. 10, a suction type hand portion 43-1 is used. A suction pad 43-1a is provided on the hand portion 43-1, and the ideal approach direction 14 of the hand portion 43-1 changes depending on the hardness and suction force of the suction pad 43-1a. In particular, since it is desirable that the suction pad 43-1a approaches the surface of the component 9a1 in the vertical direction, the allowable approach direction 15 is narrower than when the hand portion 43 shown in FIG. 10 is used. Considering this, it is not desirable to carelessly change the approach trajectory before and after gripping, which contributes to the gripping success rate, together with the interference check.

As described above, the constraint conditions on the tool unit 42 side for the gripping point candidates have been described so far. Next, the constraint conditions on the component 9a1 side for the gripping point candidates will be described.

When there is a model, it can be grasped in advance that each of the plurality of parts 9a is lightweight by modelless matching using the model information 3a. At this time, in order to prevent a couple from being generated with respect to the gripping point candidate 17 shown in FIG. 12 and the part 9a from being flipped by the fingertip of the hand portion 43 (not shown), the gripping point candidate 17 is subjected to. , The permissible travel vector 18 including the distance is defined. The permissible progress vector 18 indicates a distance at which the magnitude of the vector can geometrically advance more than the grip point candidate 17, and a magnitude of a force that can be applied to the grip point candidate 17. That is, the gripping point candidate 17 defines the upper limit of the load that should not be applied because the gripping phenomenon occurs.

As for the evacuation direction, as shown in FIG. 13, an allowable evacuation vector 19 including a distance is defined. The permissible evacuation vector 19 indicates how much the hand portion 43 may be pulled up when the tool portion 42 is moved to the gripping position and gripped, and the width of the vector can be any direction. It is an index of whether it can be raised with less influence on other objects. The trajectory with the least amount of movement that satisfies these gripping constraints is defined as the effective first approach trajectory 22a.

The second approach orbit generation unit 23 starts the effective first approach orbit 22a in examining the interference avoidance orbit passing through the effective first approach orbit 22a generated by the first approach orbit generation unit 22. An intermediate trajectory connecting the point Psg and the start point of the picking operation is generated. Here, the second approach orbit 23a is an orbit defined for distinguishing the movement in free space with respect to the effective first approach orbit 22a, which is not directly related to the success rate of the gripping operation. Therefore, although there are various starting points, the ending point is always the starting point of the effective first approaching orbit 22a.

The second approach trajectory generation unit 23 operates the tool unit 42 at high speed by designating the picking operation start point attitude with as little change in attitude as possible with respect to the position / orientation of the starting point of the effective first approach trajectory 22a. be able to. Regarding the generation of interference avoidance orbitals, the orbital search for avoiding interference when generating each orbital may be performed in Cartesian coordinates or in the configuration space. When searching for an orbit in an offline search, a generally known search method can be used. As the search method, RRT (Rapid Random Tree) can be exemplified.

In the second approach trajectory 23a shown in FIG. 14, the robot hand model 101 and the tool model 103 are effective so that the robot hand model 101 and the tool model 103 do not interfere with the peripheral device model 102 of the parts box 9. It is an interference avoidance orbit that moves to the starting point of the first approaching orbit B1'.

The avoidance trajectory generating unit 24 shown in FIG. 6 has an effective gripping posture 21a of the tool unit 42 obtained by the gripping posture generating unit 21 and an effective first effective first of the tool unit 42 obtained by the first approaching trajectory generating unit 22. The approaching orbit 22a and the second approaching orbit 23a of the tool unit 42 obtained by the second approaching orbit generation unit 23 are connected and output to the robot control device 3 as an interference avoidance orbit 2a. The robot control device 3 executes a bin picking operation based on the interference avoidance trajectory 2a. The orbit calculation unit 11 outputs a plurality of effective gripping postures 21a, an effective first approaching orbit 22a, and a second approaching orbit 23a, and if there are a plurality of combinations, an evaluation function is defined and a score is given. It is possible to take a method in which the value exceeds the threshold value and the one with the highest score is executed. As the evaluation function, it is possible to select a trajectory that minimizes the time required to move the entire interference avoidance trajectory 2a, that is, the total working time of the robot. Further, as the evaluation function, the evaluation value can be calculated so as to minimize the energy consumption by inputting the energy consumption calculated based on the value of the current required for the robot operation. The evaluation function method is not limited to these.

FIG. 15 is a flowchart for explaining the operation of the interference avoidance device according to the first embodiment of the present invention. The interference avoidance device 2 calculates a plurality of gripping point candidates 10a based on the measurement data 1a, and generates an effective gripping posture 21a that is unlikely to interfere with the calculated gripping point candidates 10a as a gripping point candidate ( S1). The interference avoidance device 2 generates an effective first approaching orbit 22a corresponding to the generated gripping point candidate (S2), and performs an interference check on the effective gripping posture 21a and the effective first approaching orbit 22a (S3). ).

If there is a possibility of interference as a result of the interference check (S4, No), the interference check unit 25 generates a part of the tool unit 42 that may interfere with the parts box 9, and interferes within the allowable posture range. A modified grip point candidate is searched for when the smallest posture change is made in order to eliminate it, and the presence or absence of the possibility of interference is determined (S5).

When there is no other solution in the allowable posture range, that is, when a calculation result that eliminates the possibility of interference in the allowable posture range cannot be obtained (S5, No), the interference avoidance device 2 repeats the processes S2 to S5. When the calculation result that eliminates the possibility of interference cannot be obtained, a new gripping point candidate having the next highest priority is selected from the gripping posture generating unit 21, and the candidate points are evaluated.

When there is another solution in the permissible posture range, that is, when a calculation result is obtained in which the possibility of interference is eliminated in the permissible posture range (S5, Yes), the effective gripping posture 21a is corrected in the interference avoidance device 2 (S6), S3. To S6 are repeated.

When there is no possibility of interference in S4 (S4, Yes), the second approach orbit generation unit 23 generates the second approach orbit 23a (S7), and the interference check unit 25 performs the interference check again (S8). ).

When there is a possibility of interference with the second approach orbit 23a (S8, No), the processes of S7 and S8 are repeated. When there is no possibility of interference with the second approach trajectory 23a (S8, Yes), the avoidance trajectory generation unit 24 generates an interference avoidance trajectory with respect to the robot control device 3 (S9).

As described above, the interference avoidance device 2 according to the first embodiment is divided into two regions, an effective first approach trajectory 22a and a second approach trajectory 23a, and the effective first one having a high gripping success rate first. After confirming that there is no possibility of interference with the approaching trajectory 22a, if the second approaching trajectory 23a has an effective solution, the gripping point that is the starting point is selected as the effective gripping point, and each trajectory is selected. Connect to make an interference avoidance trajectory. With this configuration, the gripping success rate can be increased while selecting gripping points that do not interfere, and the work efficiency of the robot system 100 can be improved as compared with the case where a conventional interference avoidance device is used.

Embodiment 2.
FIG. 16 is a configuration diagram of a trajectory calculation unit included in the interference avoidance device according to the second embodiment of the present invention. Hereinafter, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted, and only the different parts will be described here. The differences between the first embodiment and the second embodiment are as follows.
(1) In the second embodiment, the orbit calculation unit 11A is used instead of the orbit calculation unit 11 of the first embodiment.
(2) The trajectory calculation unit 11A is attached to the gripping posture generation unit 21, the first approach trajectory generation unit 22, the second approach trajectory generation unit 23, the avoidance trajectory generation unit 24, and the interference check unit 25 included in the trajectory calculation unit 11. In addition, an interference risk evaluation unit 26 is provided.

FIG. 17 is a first diagram for explaining the operation of the interference risk evaluation unit shown in FIG. The distance information Lij is the distance between the robot hand model 101, which is an object that wants to avoid mutual interference, and the parts box 9, or the distance between the tool model 103, which is an object that wants to avoid mutual interference, and the parts box 9. .. Interference is usually avoided by keeping them at a certain distance or longer. Therefore, if the high-precision measurement results of the measurement unit and the accurate relative distance relationship between the peripheral device and the robot calculated based on the measurement results are always known, these are kept at a certain distance or more. It is important to control the existence, and the second approach orbit generator selects an orbit in which these are above a certain level. However, an accurate relative distance relationship may not be obtained due to the influence of calibration error and noise / relative distance modeling error. In this case, if an accurate relative distance relationship cannot be obtained in the second approach orbit generator, the interference risk in the second approach orbit is evaluated based on the approach distance Lij, and the risk is high. For the conceivable part, it is desirable to adjust the execution speed of the second approach trajectory so as to reduce the damage in the case of actual collision by adjusting the movement speed.

The interference risk evaluation unit 26 shown in FIG. 16 receives the start point information of the effective first approach orbit 22a and the model information 3a as inputs, and is between the object i and the object j with respect to the second approach orbit generation unit 23. Calculates the distance information Lij of. The object i and the object j may be objects such as the robot hand model 101, the tool model 103, and the parts box 9 shown in FIG. 17 that are desired to avoid interference. The interference risk evaluation unit 26 is a distance between the object i and the object j based on the position information of each model such as the arm unit 41, the tool unit 42, the peripheral device and the parts box 9 and the measurement data 1a included in the model information 3a. The information Lij is calculated.

FIG. 18 is a second diagram for explaining the operation of the interference risk evaluation unit shown in FIG. In the upper part of FIG. 18, the vertical axis is the approach speed Lij'calculated by dividing the difference of the distance information Lij by the time, and the horizontal axis is the time. In the lower part of FIG. 18, the vertical axis is the distance information Lij and the horizontal axis is the time. As shown in FIG. 18, the second approach orbit generation unit 23 shown in FIG. 16 confirms whether or not the distance information Lij has reached the approach distance threshold value 31b, or the rate of change of the approach distance, that is, the approach speed Lij. It is confirmed whether or not'exceeds the speed upper limit value 31a of the approach speed that changes according to the distance information Lij. In the example shown in FIG. 18, when the approach distance Lij approaches the interference check threshold value 31b, the speed upper limit value 31a is set to be reduced. That is, in the case of an evaluation in which the risk of interference increases, the permissible movement speed is reduced. If a movement speed higher than the reduced speed is set, the movement speed of the robot is adjusted so that the movement speed can be reduced to the speed upper limit value 31a.

Even if the interference check determines that there is no possibility of interference, interference may occur if sensing information and modeling errors occur. Normally, in anticipation of these, the risk of collision between the tool unit and the surrounding environment is reduced by taking a "judgment margin" that sets a large threshold value for determining interference with respect to the approach distance Lij of all interference checks. To do. However, by taking this determination margin, the determination may become excessive and it may be erroneously determined that "interferes" more than necessary. As a result, the number of orbitals that can be grasped is extremely reduced. According to the interference avoidance device 2 according to the second embodiment, even when it is desired to reduce the determination margin for the purpose of avoiding the excessive erroneous determination and the required work time is short and the operation is high speed, the interference risk is high. The hand unit 43 can be moved by adjusting the command value to a speed at which the damage level of the object is low based on the approach distance Lij and the approach speed Lij'.

While maintaining that the damage level is low when the peripheral device and the robot approach each other as described above, the operating speed can be increased as necessary for the entire trajectory. For example, when the speed upper limit value 31a of the approach speed Lij'between each model is satisfied, a part where the difference between the actual approach speed 30a and the speed upper limit value 31a is particularly large is searched, and the moving speed of the robot in those parts is greatly adjusted. can do. In this case, the approach speed 30a shown on the upper side of FIG. 18 increases and approaches the speed upper limit value 31a, and the approach distance 30b shown on the lower side of FIG. 18 is compressed with respect to the time axis (horizontal axis) and in the vertical axis direction. The value of is unchanged. By repeating increasing the robot operating speed at a certain time, the operating speed of the second approaching orbit generated by the second approaching orbit generation unit can be maximized. As an actual adjustment method, it is necessary to consider that the maximum acceleration at which each axis of the robot arm can move changes depending on the posture of the robot arm in the second approach trajectory. First, the relationship between the approach speed and the approach distance when the robot arm is moved at the maximum speed in each posture is first obtained. Then, the speed can be maximized by finding a portion where the approach speed 30a exceeds the speed upper limit value 31a and adjusting to correct these.

The interference risk evaluation unit 26 according to the second embodiment pays particular attention to the relative distance between the hand unit 43 and the peripheral device and the relative approach speed between the hand unit 43 and the peripheral device as the distance between the objects that pose the interference risk. If there is a risk of exceeding the interference speed allowed by each component, the speed can be reduced to prevent damage to the hand portion 43 and the component 9a while suppressing a decrease in work efficiency, and the hand portion 43 and the component 9a can be prevented from being damaged. There is no time loss required for replacement, and the work efficiency of the robot system 100 can be further improved.

Embodiment 3.
The interference avoidance device 2 according to the third embodiment is the same as the interference avoidance device 2 according to the second embodiment, the gripping posture generation unit 21, the first approach trajectory generation unit 22, the second approach trajectory generation unit 23, and avoidance. It includes an orbit generation unit 24, an interference check unit 25, and an interference risk evaluation unit 26. In the third embodiment, an operation example of the interference avoidance device 2 in which the potential method is applied to the second approach orbit generation unit 23 according to the second embodiment will be described. The potential method defines a virtual energy field between objects, and defines a virtual external force as a repulsive force (dimension of force) acts as the distance between two objects approaches. Assuming that this virtual external force acts, the potential method is to apply this virtual external force to the robot arm, obtain the displacement of the arm based on the equation of motion, and correct the displacement amount as the correction amount at each point of the orbit. This is the concept of orbit correction in. In addition, a vector amount representing the trajectory correction amount (position dimension) of the position or posture is calculated assuming that the object moves away by the virtual external force. Assuming that the robot model is one of the objects, when generating the command value at each point, the definition works at a position that is pushed away by a certain amount from the original command value based on the calculated repulsive force or orbit correction amount vector. To do. The trajectory correction using the potential method is a method of virtually correcting the hand control trajectory based on the above procedure. The second approach orbit generation unit 23 according to the third embodiment acts on the tool unit 42 a virtual external force which is a repulsive force according to the distance information Lij obtained by the interference risk evaluation unit 26, and causes the second approach orbit. Is used as the reference orbit and the reference orbit is modified by using the potential method.

FIG. 19 is a diagram showing the operation of the robot hand operated by the interference avoidance device according to the third embodiment. A virtual external force 32, which is a repulsive force according to the distance information Lij obtained by the interference risk evaluation unit 26, acts on the hand unit 43. Further, the interference avoidance device 2 outputs virtual external force information indicated by the virtual external force 32 to the robot control device 3 shown in FIG. 2 in addition to the interference avoidance trajectory 2a including the second approach trajectory 23a shown in FIG. To do.

The robot control device 3 makes the hand unit 43 follow the second approaching trajectory 23a as the second approaching trajectory P, and performs impedance control according to the virtual external force information. In the potential method, the resultant force of forces is interpreted as the moving speed as it is, multiplied by an appropriate coefficient to obtain the position correction amount ΔP, and the position control can be performed with the second approach trajectory P + the position correction amount ΔP as the target value. .. Here, an example of how to obtain the second approach orbit P + position correction amount ΔP is shown. In FIG. 19, when the tip of the tool portion of the robot is moving in the direction of the velocity vector V along the second approach trajectory P, the virtual external force 32 acts in two places according to the distance between the tip of the tool portion and the box. It shows how it is doing. In this case, the robot control device 3 corrects the magnitude and direction of the velocity vector V according to the virtual external force 32, and sets the corrected velocity vector as V'. The robot control device 3 corrects the target value by setting the corrected speed vector V'and the amount ΔTc * V'multiplied by the control cycle ΔTc as the position correction amount P + the position correction amount ΔP. Expressed by the relationship between the virtual external force F and the position correction amount ΔP instead of the velocity vector, the position correction amount ΔP is selected so that K * ΔP is balanced with the external force action F, where K is the virtual spring rigidity of impedance control. You can also do it. As a result, in the third embodiment, it is possible to respond to the online situation change that could not be obtained in the second embodiment, and even if a sudden environmental change occurs, the robot system 100 can be operated without being damaged. System operational efficiency can be maintained.

Embodiment 4.
FIG. 20 is a configuration diagram of a trajectory calculation unit included in the interference avoidance device according to the fourth embodiment of the present invention. Hereinafter, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted, and only the different parts will be described here. The trajectory calculation unit 11B included in the interference avoidance device 2 according to the fourth embodiment is the same as the trajectory calculation unit 11 included in the interference avoidance device 2 according to the first embodiment, the gripping posture generation unit 21 and the first approach trajectory generation. A unit 22, a second approach orbit generation unit 23, an avoidance orbit generation unit 24, and an interference check unit 25 are provided. In the fourth embodiment, the effective gripping posture 21a is input to the first approaching trajectory generating unit 22, and the hand opening / closing speed 33 and the hand opening / closing time 34 are input to the first approaching trajectory generating unit 22 as gripping approach constraints. Will be done.

In the field of welding technology represented by a servo gun, there is a technology for automatically setting a trigger of the servo gun in anticipation of statically indeterminate of the arm in order to shorten the welding time. As a fact related to this, even in gripping, the hand opening / closing speed and the gripping start time are important and are related to the gripping success rate. In particular, it is necessary to execute a hand opening / closing operation suitable for each servo gun attached to the robot hand in order to increase the success rate, rather than defining the first approach trajectory in detail.

The first approach trajectory generating unit 22 according to the fourth embodiment evaluates the gripping approach restraint, the trajectory generation in consideration of the hand opening / closing speed 33 and the hand opening / closing time 34, and the hand opening / closing instruction, and evaluates the effective first approach trajectory 22a. To generate. When the hand unit 43 is a hand using air pressure, the response time of the hand cannot be changed for each part. When the hand opening / closing is not in time for the effective first approaching trajectory 22a, the unnecessary waiting time can be reduced by setting the hand opening / closing time in the avoidance trajectory generation unit 24. Such determination of the hand opening / closing time is determined from the time required for the effective first approaching trajectory 22a in the avoidance trajectory generating unit 24.

As described above, in the fourth embodiment, since the picking operation can be determined in consideration of the hand opening / closing time 34, it is possible to reduce the delay of one operation related to the hand opening / closing and shorten the tact time. it can. Further, in the fourth embodiment, by considering the hand opening / closing speed in addition to the trajectory as a gripping approach constraint, in addition to the effect of the first embodiment, the gripping operation on the trajectory can be controlled more finely, and the gripping is successful. The rate can be improved.

FIG. 21 is a hardware configuration diagram of the interference avoidance device according to the first to fourth embodiments of the present invention. The interference avoidance device 2 includes a CPU (Central Processing Unit) 61, a ROM (Read Only Memory) 62, a RAM (Random Access Memory) 63, and an input unit 65. In the interference avoidance device 2, the CPU 61, the ROM 62, the RAM 63, and the input unit 65 are connected via the bus line 66.

The input unit 65 includes a mouse and a keyboard, and inputs information input by the user. The information input to the input unit 65 is sent to the CPU 61. The program 60 for the interference avoidance device 2 is stored in the ROM 62. When the interference avoidance device 2 according to the first to fourth embodiments is realized, the CPU 61 executes the program 60 loaded in the RAM 63, so that the grip point candidate generation unit 10 and the trajectory calculation unit 11 of the interference avoidance device 2 are executed. It will be realized.

FIG. 22 is a diagram showing a modified example of the production system shown in FIG. The production system 200 shown in FIG. 22 includes an image processing device 1001 in addition to the components of the production system 200 shown in FIG. The image processing device 1001 is provided between the measuring unit 1 and the interference avoiding device 2. The image processing device 1001 is a device having a function of the gripping point candidate generation unit 10 extracted from the interference avoidance device 2. That is, the image processing device 1001 is a device including the gripping point candidate generation unit 10 of FIG. 4 that performs image processing on the measurement data 1a and calculates the gripping point candidate 10a.

FIG. 23 is a diagram showing a configuration example of the interference avoidance device shown in FIG. When the image processing device 1001 is used in FIG. 22, as shown in FIG. 23, the interference avoidance device 2 removes the grip point candidate generation unit 10 of FIG. 4, and the interference avoidance device 2 includes grip point candidates 10a, model information 3a, and so on. A trajectory calculation unit 11 that uses the robot program 3b and the setting information 3c as input information is provided.

Further, since the production system 200 of FIG. 22 is configured to transmit the gripping point candidate 10a which is the image processing result from the image processing device 1001, the processing result is shared via a network such as Ethernet (registered trademark). be able to.

FIG. 24 is a diagram showing a first modification of the production system shown in FIG. 22. The production system 200 shown in FIG. 24 is configured such that the gripping point candidate 10a obtained as a result of image processing is received by the robot control device 3. The production system 200 may be configured so that the gripping point candidate 10a is received by both the robot control device 3 and the interference avoidance device 2.

FIG. 25 is a diagram showing a second modification of the production system shown in FIG. The production system 200 shown in FIG. 25 includes an information integrated terminal 5 using a PLC, a personal computer, or the like, manages all information collectively by the information integrated terminal 5 via a network, and operates as a whole according to a state. It is configured to output change instructions or commands. The gripping point candidate 10a is input to the information integrated terminal 5, and the gripping point candidate 10a input to the information integrated terminal 5 is input to the interference avoidance device 2 via the robot control device 3.

FIG. 26 is a diagram showing a third modification of the production system shown in FIG. The production system 200 shown in FIG. 26 includes a plurality of image processing devices 1001, 1002 and a plurality of measurement units 1, 1A. The measuring unit 1A is installed at a position where the robot 4 can be photographed by the fixed base 70. The measurement unit 1A transmits the image pickup information obtained by imaging the operation of the robot 4 to the image processing device 1002 as measurement data 1a.

The image processing device 1002 has the same configuration as the image processing device 1001, and calculates the gripping point candidate 10b based on the measurement data 1b. The calculated gripping point candidate 10b is input to the information integration terminal 5. The information integration terminal 5 aggregates the gripping point candidates 10a and 10b, and outputs an instruction or command for changing the operation as a whole according to the state.

In the present embodiment, an example using the measuring unit 1 fixed to the robot 4 and the measuring unit 1A installed in a place other than the robot 4 is shown, but the production system 200 according to the present embodiment measures. The configuration may be such that only one of the unit 1 and the measurement unit 1A is used. Although not shown, when the interference avoidance device 2 calculates the interference avoidance trajectory of the entire object other than the robot 4, the information integration terminal 5 is configured to include the interference avoidance device 2 and the information integration terminal 5 is a conveyor control device. 6. It may be configured to function as the interference avoidance device 2 of each of the processing machine control device 7 and the robot control device 8.

Embodiment 5.
FIG. 27 is a configuration diagram of a trajectory calculation unit included in the interference avoidance device according to the fifth embodiment of the present invention. The orbit calculation unit 11C shown in FIG. 27 replaces the first approach orbit generation unit 22 and the second approach orbit generation unit 23 shown in FIG. 6 with the first approach orbit generation unit 22A and the second approach orbit generation unit 23. A unit 23A is provided. In addition to the first approach trajectory generation unit 22A and the second approach trajectory generation unit 23A, the trajectory calculation unit 11C includes a gripping posture generation unit 21, an avoidance trajectory generation unit 24, and an interference check unit 25 shown in FIG. In FIG. 27, the gripping posture generation unit 21, the avoidance trajectory generation unit 24, and the interference check unit 25 in FIG. 6 are not shown. Hereinafter, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted, and only the different parts will be described here.

The first approach orbit generation unit 22A includes an orbital element generation unit 83 and an approach orbit generation unit 84.

The orbital element generation unit 83 calculates M + 1 first approaching orbital elements 13a based on the M intermediate goal information 81 and the effective gripping posture 21a regarding the first approaching orbit. M is an integer greater than or equal to 1. k is a variable from 1 to M + 1. The orbital element generation unit 83 calculates the first approaching orbital element 13a in order from k = 1 to k = M + 1. The first approaching orbital element is defined by interpolating both end points with two positions (two of a gripping point, a waypoint, an operation start point, and an operation completion point) as both end points. As the interpolation method, spline interpolation can be exemplified. The intermediate goal is a gripping point candidate Pgg which is a target position of the tool unit and a gripping approach start point Psg of the tool unit which is a starting point of a first approaching trajectory indicating a position separated from the target position Pgg of the tool unit by a certain distance. It is the waypoint of the orbit defined between. The intermediate goal information 81 is information indicating the contents of the intermediate goal.

The approach orbit generation unit 84 stores each of the first approach orbit elements 13a calculated in order from k = 1 to k = M + 1, and connects each of the plurality of first approach orbit elements 13a in the order of storage. Thereby, the effective first approach orbit 22a is generated. For example, the first calculated first approach orbit element 13a is connected to the second calculated first approach orbit element 13a, and the second calculated first approach orbit element 13a is connected to 3 The first calculated first approach orbital element 13a is connected. By executing such processing in order from the first approaching orbital element 13a calculated by k = 1 to the first approaching orbital element 13a calculated by k = M + 1, the effective first approaching approach is performed. The orbit 22a is generated. When k = 1, the approaching trajectory element connecting the gripping point candidate Pgg and the first intermediate goal related to the first approaching trajectory is calculated. When k = M + 1, the approach orbital element connecting the Mth intermediate goal related to the first approach orbit and the gripping approach start point Psg which is the starting point of the first approach orbit is calculated. As a method of connecting the two approaching orbital elements, the following method of connecting the approaching orbital elements can be applied for the purpose of smoothly transitioning the robot movement. The first connection method is a connection method that takes speed into consideration. The first approach orbit generation unit can define the approach orbit so as to be slow and slow in acceleration / deceleration in consideration of the influence of inertial force and centrifugal force generated in the vicinity of the intermediate goal which is the connection point. At this time, the connection points of the two approaching orbital elements are connected as trajectories that are not discontinuous, and are connected so that the speed command value in the vicinity of the connection points does not increase. This is a connection method in which when the magnitude of the speed of the movement direction defined by the motion trajectory changes suddenly before and after the connection point, the robot decelerates appropriately to realize a smooth robot motion. Normally, speed information is not always required for the orbit, but here it is necessary to have a passing speed that can be realized by the tool part of the robot. Explained as a case. The second connection method is a connection method that smoothly connects waypoints using a spline curve. The first approach trajectory generating unit generates a smooth trajectory by spline interpolation based on the gripping approach start point Psg which is the starting point of the first approaching trajectory, the gripping point candidate Pgg which is the ending point, and the intermediate goal. You can also do it. Here, the role of the intermediate goal will be explained. In the first embodiment, when the effective gripping posture 21a is determined, the trajectory candidate is calculated using the gripping approach start point Psg of the tool portion and the gripping point candidate Pgg of the tool portion. On the other hand, in the present embodiment, in addition to the grip point candidate Pgg calculated from the grip points represented by the effective grip posture required for picking, M intermediate goals are set as transit points that always pass. These intermediate goals can be obtained in several ways. For example, there are cases where the user automatically extracts the intermediate goal from the successful case after having the robot perform a preliminary work trial, or there is a case where the intermediate goal is automatically extracted by learning from the successful case in the preliminary simulation. .. That is, in the case where the gripping point fails to be gripped when going straight from the normal direction to the gripping point, it is necessary to give a target point immediately before the gripping position. This target point becomes the intermediate goal 81. A case where one intermediate goal is set with M = 1 will be described. Consider the case where an object is gripped and there is a constraint in the approach vector direction immediately before the gripping position. Here, the "constraint" refers to the approach vector direction when there is a vector that cannot be specified as the approach vector direction. The approach vector direction that cannot be specified is set when the following events occur when the robot moves in the approach vector direction. Specific examples of the above-mentioned events include an event in which the tool part and end effector of the robot interfere with an obstacle, an event in which the work of the gripping target is hindered (falling of the gripping target, damage to the gripping target), and the like. Can be mentioned. When the fingertip is brought closer to the gripping point without changing the posture from the position offset by 10 mm from the gripping posture, an intermediate goal is set at a position offset by 10 mm from the gripping point candidate Pgg. Here, the "offset position" means "another position that is translated by a certain amount of position (mm) in a certain direction from a certain reference position". The "position offset by 10 mm" shown here is a position translated in the direction in which the robot can successfully grip, excluding the "vector that cannot be specified as the approach vector direction" explained as a constraint. On the other hand, the difference between the points that are not intermediate goals (grasping point candidate Pgg and gripping approach start point Psg) and the method of determining the intermediate goal will be supplementarily explained. As described above, the gripping point candidate is calculated based on the measurement data. The end point on the side of the first approaching trajectory that is not the gripping point Pgg, that is, the gripping approach start point Psg, is the position where the robot that grips the parts to be taken out moves to a height or position where interference between the parts to be taken out and the surrounding parts disappears. Set. That is, a position different from the intermediate goal is set. However, here, the parts contained in the supply box and selected as the gripping point candidates are called "parts to be taken out", and the other parts contained in the supply box are called "surrounding parts". Further, the intermediate goal is defined only when it is necessary to define the target point immediately before the gripping position, and the intermediate goal is not set unless there is a restriction in the approach vector direction immediately before the gripping position.

The second approach orbit generation unit 23A includes an orbital element generation unit 85 and an approach orbit generation unit 86.

The trajectory element generation unit 85 has a gripping approach start point Psg, which is the starting point of the effective first approach trajectory 22a, and a start point of the second approach trajectory 23a, which is the robot operation start point, among the effective first approach tracks 22a. Based on the start point of the picking operation and the N intermediate goal information 82 regarding the second approach trajectory, N + 1 second approach trajectory elements 13b are calculated. N is an integer greater than or equal to 1. j is a variable from 1 to N + 1. The orbital element generation unit 85 calculates the second approaching orbital element 13b in order from j = 1 to j = N + 1. When j = 1, the orbital element generation unit 85 calculates an approaching orbital element that connects the gripping approach starting point Psg of the effective first approaching orbital 22a and the first intermediate goal related to the second approaching orbital. When j = N + 1, the orbital element generation unit 85 calculates an approaching orbital element that connects the Nth intermediate goal with respect to the second approaching orbit and the start point of the picking operation. The intermediate goal information 82 is information defined by the position (X, Y, Z) and the posture (rotation angle (A, B, C) / rotation matrix R) of the robot tool unit. However, the start point of the picking operation, which is the start point of the second approach orbit 23a, is defined in the orbital element generation unit 85. For example, as explained in [0076], the starting point of the picking operation is the sky above the shelf or box (a part of the surrounding environment) containing the target parts, or the arm or hand and the surrounding environment interfere with each other. Points that are not far enough apart are designed and specified by the user. As another method, the starting point of the picking operation can be defined as a point acquired exploratoryly as described in [0083] and [0084]. Even in the case of exploratory acquisition, the user defines and sets a point at which the hand is sufficiently separated from the box as the end condition of the search.

The approach orbit generation unit 86 stores the second approach orbit elements 13b calculated in order from j = 1 to j = N + 1, and connects each of the second approach orbit elements 13b in the order of storage. , Generates a second approach orbit 23a.

Here, as shown in FIG. 5, in consideration of the component to be gripped and the geometric shape of the hand, the effective first approach is made so that the fingertip of the hand portion 43 does not interfere with the convex portion 12 of the component 9a. The orbit 22a is generated. However, in the generation of the effective first approaching trajectory 22a, when applying the method of performing the trajectory search to avoid interference, it may be necessary to set an intermediate goal. For example, in conjunction with the opening and closing of the fingertips of the gripping hand, the action of slightly closing the fingers of the gripping hand at the intermediate goal immediately before the gripping posture is performed as one of the robot actions, thereby geometrically holding the gripping object. It is possible to exemplify a case where the state is changed to a trapped state in the space of the fingertip, the gripping object is further moved to the target gripping point, and then the gripping target is gripped. The state in which the gripping object is geometrically trapped in the space of the fingertip of the hand is a state in which the spatial movement is restricted or a caging state. A condition in which spatial motion is constrained is that, for example, when the fingertips of the gripping hand are close to each other in a region slightly larger than the part, the part comes into contact with the fingertip when trying to rotate in the fingertip of the gripping hand. It represents a state in which the parts cannot rotate. The part to be gripped does not displace significantly as it goes out from the gap between the fingers, and it is possible to keep the posture change within a range that does not make gripping impossible. When trying to move to the gripping point candidate Pgg by the gripping operation using such an intermediate goal, it is possible to prevent the parts that are likely to fall over from falling. Caging is an object constraint that surrounds the object so that it cannot escape in either direction, although there is no contact geometric constraint. Also in this case, it is an object to prevent the event that the part falls or becomes impossible to grip when the part is displaced by an external force other than the acting force on the part due to the opening and closing of the fingertip.

For the same reason, even when the second approach trajectory 23a is generated, an operation for increasing the gripping success rate can be set by providing an intermediate goal. For example, if the position of the center of gravity of the object deviates from the gripping point of the robot hand and the moment increases during the transportation of the object, the object being transported may fall. In order to prevent such a situation, an intermediate goal in which the robot hand posture is set by the following method can be selected as the intermediate goal in the second approach trajectory. The second approach trajectory generating unit 23A minimizes the distance between the gripping point and the position of the center of gravity of the object in the direction perpendicular to the vertical direction, and stably grips the gripping object so as to prevent it from falling off due to the action of a moment. The posture can be set as the posture of the gripping hand of the robot with the intermediate goal. The distance with respect to the direction orthogonal to the vertical direction corresponds to the distance from the gripping point of the robot hand to the position of the center of gravity of the object. The position of the intermediate goal corresponding to the posture of the gripping hand can be calculated as follows. The second approach trajectory generating unit 23A calculates the height at which the gripping hand and the surrounding environment do not interfere with each other even in the stable gripping posture of the parts box 9 and the gripping object, and the stable gripping posture until the height reaches the height at which the gripping object does not interfere with each other. The position of the intermediate goal can be set to take the stable gripping posture after reaching a height that does not interfere with the position. Here, for the height that does not interfere, for example, the gripping posture is calculated from the object data measured in advance, and the calculated gripping posture and the geometric data of the object acquired in advance interfere with the parts box or the like. It can be obtained by calculating the distance that does not occur.

As described above, according to the interference avoidance device according to the fifth embodiment, in addition to the effect of the first embodiment, it is possible to prevent the gripped object from falling out of the gripped state, and as a result, the productivity of the system is improved. The effect of doing is obtained.

Embodiment 6.
FIG. 28 is a configuration diagram of a trajectory calculation unit included in the interference avoidance device according to the sixth embodiment of the present invention. The orbit calculation unit 11D shown in FIG. 28 replaces the first approach orbit generation unit 22 and the second approach orbit generation unit 23 shown in FIG. 6 with the first approach orbit generation unit 22B and the second approach orbit generation unit 23. A unit 23B is provided. Further, the track calculation unit 11D includes an assembly posture candidate generation unit 27 and an assembly position candidate generation unit 28 instead of the gripping posture generation unit 21 shown in FIG. In the sixth embodiment, the gripping point candidate is replaced with the “assembly posture candidate” as the configuration changes to the assembly work of the gripped object instead of the gripping of the object, and the gripping approach start point (starting point of the first approach trajectory). ) Is replaced with "assembly operation start point". The starting point of the picking operation, which is the starting point of the robot operation, is replaced with the "starting point of the entire assembly operation". The assembly position candidate generation unit 28 may be provided outside the track calculation unit 11D. Hereinafter, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted, and only the different parts will be described here.

First, the hand unit 43 measures the position of the component 9a by utilizing a camera or an image sensor, and grips the component. At this time, when the supply form is the bulk supply and the parts are in the bulk stack state, the robot starts the entire assembly operation by the same process as in the first embodiment in which the parts are above the parts after grasping the parts 9a. Move to point Psa. After that, the robot operates according to the trajectory generated by the trajectory calculation unit 11D. The starting point Psa of the entire assembly operation is generated by the second approach orbit generation unit. Up to the assembly operation start point, or at the assembly operation start point, the interference avoidance device 2 measures the position and orientation of the object being gripped by utilizing the vision sensor or the camera which is the measurement unit, and the measurement is measured. Information (RGB (Red Green Blue) image information, distance image information such as point cloud, distance information) By performing image recognition processing, the position and orientation of the object grasped by the hand is calculated. In the image recognition process, a model matching process or the like is used. As a result, the "positional posture of the part", which is how the part is gripped with respect to the hand, is acquired. However, the position and orientation of the parts are measured before gripping, assuming that the gripping hand succeeded in gripping the parts in an ideal state without slipping or misalignment with respect to the position and posture of the parts acquired for gripping the parts. It is also possible to perform calculation based on the position / orientation information of the parts. The assembly position candidate generation unit 28 calculates the gripping posture information 87 expressed by the tool position / posture of the robot based on the position / posture of the parts. The assembly position candidate generation unit 28 uses the gripping posture information 87 with respect to the tool unit to be gripped based on the model information of the robot and the peripheral device, and the tool unit completes the assembly of the gripping target. Candidate 88 is calculated. In the first to fifth embodiments, there are often a plurality of posture candidates that can be generated by the gripping posture generating unit 21. On the other hand, in the sixth embodiment, there is only one candidate posture at the time of completion as in the case of assembling the part 9a to the part 9b as shown in FIG. 29, and there is only one first assembly posture candidate 88. May be set. In the sixth embodiment, as an example of the case where there are a plurality of first assembly posture candidates 88 generated by the assembly position candidate generation unit 28, there is a case where the part shape is a rectangular parallelepiped, a cylinder, or a disk. When the component shape is a rectangular parallelepiped, a cylinder, or a disk, the assembly position candidate generation unit 28 sets a plurality of first assembly posture candidates 88 due to the symmetry of the component. The assembly posture candidate generation unit 27 generates a second assembly posture candidate capable of realizing the assembly work including an allowable error. That is, the assembly posture candidate generation unit 27 generates a plurality of effective assembly posture candidates 27a that exist within the permissible posture range without the tool unit interfering with the peripheral device for the second assembly posture candidate. The effective assembly posture candidate 27a includes position information and posture information ([X, Y, Z, A, B, C]).

FIG. 29 is a diagram for explaining the operation by the trajectory calculation unit shown in FIG. 28. In FIG. 29, the tool unit 42 of the robot approaches the component box 9 which is the component supply box, the hand unit 43 grips the component 9a which is the object to be gripped in the component box 9, and then the hand unit 43 is the component. The operation of moving the 9a to the upper side of the component 9b and assembling the component 9a held by the hand portion 43 to the component 9b is shown.

The robot that takes out the object to be gripped from the parts box 9 may perform product assembly work in the factory in addition to the gripping operation of the object. As shown in FIG. 29, when a product is assembled by assembling the component 9a to the component 9b, the component 9b has a fixing portion 80 to which the component 9a is fitted by a snap fit, a U-shaped protrusion 9b1, and the like. May exist. Snap-fit is a type of mechanical joining method used to bond two or more materials, and is a method of fixing two or more materials to each other by fitting two or more materials together using the elasticity of the materials. That is. Therefore, when assembling the product, the robot does not allow the tip of the component 9a to interfere with the protrusion 9b1 of the component 9b, and the horizontal ends of the component 9a do not rest on the upper surface of the fixing portion 80. It is necessary to assemble the component 9a to the component 9b.

However, when the position and angle immediately before the assembly completion of the component 9a on the component 9b is compared with the assembly completion position and angle of the component 9a on the component 9b, the angle of the extension direction of the component 9a with respect to the extension direction of the component 9b is Not only are they different, but the positions of the tips of the parts 9a with respect to members such as the fixing portion 80 and the protrusions 9b1 of the part 9b are different. The assembly completion position is the position of the bottommost part 9a among the plurality of parts 9a existing in the part 9b. In this way, when the component 9a is assembled to the component 9b having members such as the fixing portion 80 and the protrusion 9b1, there may be restrictions on the insertion direction, insertion angle, etc. of the component 9a into the component 9b. Further, for example, when the assembly operation of the component 9a to the component 9b is started in the vertical direction from the position where the assembly completion position of the component 9a is extended vertically above the component 9b, the component 9a interferes with the protrusion 9b1 of the component 9b. There is a risk. Therefore, in addition to the assembly position candidate point which is the final destination of the part 9a, the relative position of the part 9a with respect to the part 9b, the relative angle of the part 9a with respect to the part 9b, etc. by passing the part 9a to a position which is an intermediate goal, etc. The assembly cannot be completed without making minor changes. That is, the effective first approach orbit 22a generated by the first approach orbit generation unit 22A of the fifth embodiment is further divided into a plurality of orbits, and the second approach orbit generation unit 23A generated by the second approach orbit generation unit 23A. The assembly may not be completed unless the approaching track 23a is further divided into a plurality of tracks.

Hereinafter, the operation of the trajectory calculation unit 11D according to the sixth embodiment when the grasped target object is assembled to another target object will be described. FIG. 30 is a flowchart for explaining the operation by the trajectory calculation unit shown in FIG. 28.

The hand unit 43 grips the supplied component 9a (S10), and the interference avoidance device 2 calculates the position and orientation of the component 9a gripped by the hand unit 43 (S11). Assembling posture candidate points for work are generated (S12). Next, in S13, the first approach orbit generation unit 22B of the orbit calculation unit 11D is moved by a part whose assembly direction or insertion direction is restricted during assembly, and the part 9a gripped by the assembly target comes into contact with the assembly target. Generates a first approach trajectory consisting of component movement with. The first approach trajectory generation unit 22B of the trajectory calculation unit 11D is a tool while satisfying a state in which the gripping part 9a and the gripping hand do not shift the assembly target among the generated plurality of effective assembly posture candidates 27a. Extract the assembly posture that allows the unit to approach the assembly target. Next, the first approach trajectory generation unit 22B generates a plurality of assembly track candidates for the extracted assembly posture candidates, and first approaches the plurality of tracks having each of the plurality of assembly posture candidates as end points. Generate as an orbit. Specifically, the first approach orbit generation unit 22B generates the k-th (here, k = 1) first approach orbit element 13a1 for M intermediate goals. In FIG. 29, the first approach orbital element 13a1 generated at this time is indicated by an upward curved arrow. Subsequently, the first approach trajectory generating unit 22B provides a trajectory for the element operation to be pressed against the fixed portion 80, and generates the k + 1st first approach trajectory element 13a2 as the element operation for inserting the member to that position. To do. In FIG. 29, the first approach orbital element 13a2 generated at this time is indicated by an arrow pointing to the upper left. The first approaching orbital element 13a2 includes a movement amount when the tip of the component 9a is inserted into the protrusion 9b1 formed on the component 9b of FIG. 29 and an inclination with respect to the horizontal direction. The locus formed by combining the first approach orbit element 13a1 and the first approach orbit element 13a2 becomes an effective first approach orbit 22a during the assembly operation of the component 9a on the component 9b. FIG. 29 shows an example in which the number of intermediate goal information 81 regarding the effective first approach trajectory 22a is one, that is, M = 1. Therefore, in the first approach orbit generation unit 22B of the orbit calculation unit 11D, M + 1 first approach orbit elements 13a are generated, that is, two are generated in the example of M = 1, so that the two first approach elements are generated. An effective first approach orbit 22a is generated by connecting each of the approach orbit elements 13a.

In S14, the interference check unit 25 performs an interference check on the effective gripping posture 21a and the effective first approach trajectory 22a. If there is a possibility of interference as a result of the interference check (S15, No), the interference check unit 25 generates a part of the tool unit 42 that may interfere with the parts box 9, and interferes within the allowable posture range. A modified grip point candidate is searched for when the smallest posture change is made in order to eliminate it, and the presence or absence of the possibility of interference is determined (S16).

When there is no other solution in the allowable posture range, that is, when a calculation result that eliminates the possibility of interference in the allowable posture range cannot be obtained (S16, No), the processes from S13 to S15 are repeated. When the calculation result that eliminates the possibility of interference cannot be obtained, a new gripping point candidate having the next highest priority is selected from the gripping posture generating unit 21, and the candidate points are evaluated.

When there is another solution in the allowable posture range, that is, when a calculation result that eliminates the possibility of interference in the allowable posture range is obtained (S16, Yes), the effective gripping posture 21a is corrected in the interference avoidance device 2 (S17), S14. The process from S15 to S15 is repeated.

When there is no possibility of interference in S15 (S15, Yes), the second approach orbit generation unit 23B of the orbit calculation unit 11D is located at the farthest position from the assembly target among the end points of the effective first approach orbit 22a. A second approach trajectory 23a is generated in which the arm portion and the tool portion of the robot approach the end point of 1 without interfering with peripheral devices (S18). Specifically, the second approach orbit generation unit 23B generates the j-th (here, j = 1) second approach orbit element 13b1 for N intermediate goal information 82. Reference numeral 13b1 shown in FIG. 29 indicates a second approaching orbital element with j = 1st. Here, the intermediate goal information 82 intends to shift the gripping posture of the part 9a from the gripping posture that is advantageous for gripping and transporting to the gripping posture that is convenient for assembly at the position above the part 9b. The waypoint is set. At this time, the end point 13b1a of the orbit at which j = the first second approaching orbit element 13b1 is connected to the assembly start point. The assembly start point is the end point 13a2a farther than the assembly position of the M + 1st first approaching orbital element 13a2. FIG. 29 shows an example in which the number of intermediate goal information 82 regarding the second approach trajectory 23a is one, that is, N = 1. The end points of the second approach orbital element 13b2 are connected to the starting point Psa of the entire assembly operation. It should be noted that the movement of the component 9a from the supply position with respect to the sky is referred to as a transport operation to distinguish it. Therefore, in the second approach orbit generation unit 23B of the orbit calculation unit 11D, N + 1, that is, two second approach orbit elements 13b are generated, so that each of the two generated second approach orbit elements 13b is generated. A second approach orbit 23a is generated in the form of being connected.

The interference check unit 25 performs the interference check again (S19). When there is a possibility of interference with the second approach orbit 23a (S19, No), the processes of S18 and S19 are repeated. When there is no possibility of interference with the second approach orbit 23a (S19, Yes), the avoidance orbit generation unit 24 is an interference avoidance orbit connecting the effective first approach orbit 22a and the second approach orbit 23a. Generate 2a (S20). A method of connecting the effective first approach orbit 22a and the second approach orbit 23a will be described. A plurality of effective assembly posture candidates 27a, an effective first approach trajectory 22a, and a second approach trajectory 23a are output, and when there are a plurality of combinations, the evaluation value becomes the smallest or the largest using the evaluation function. Select the orbit of the thing. As the evaluation function, it is possible to select a trajectory that minimizes the evaluation value with respect to time while inputting the total working time corresponding to the movement of the entire interference avoidance trajectory. Further, as the evaluation function, the evaluation value can be calculated so as to minimize the energy consumption by inputting the energy consumption based on the current value due to the robot operation. The method of the evaluation function is not limited to these.

As described above, according to the interference avoidance device according to the sixth embodiment, even when the product is assembled by assembling the component 9a to the component 9b, the effective first approaching track 22a is divided into a plurality of tracks. Since the second approach track 23a is divided into a plurality of tracks, the component 9a can be assembled to the component 9b without the component 9a interfering with the component 9b even when the fixing portion 80 or the like exists in the component 9b. ..

Embodiment 7.
FIG. 31 is a configuration diagram of a trajectory calculation unit included in the interference avoidance device according to the seventh embodiment of the present invention. The trajectory calculation unit 11E shown in FIG. 31 is in addition to the gripping posture generation unit 21, the first approach trajectory generation unit 22, the second approach trajectory generation unit 23, the avoidance trajectory generation unit 24, and the interference check unit 25 shown in FIG. The simulation unit 300 is provided. The simulation unit 300 includes a 3D model simulation unit 301, a learning device 302, a first approach orbit candidate storage unit 303, and a second approach orbit candidate storage unit 304.

The 3D model simulation unit 301 simulates the robot movement in the constructed virtual space based on the 3D-CAD model or the 3D model obtained by the 3D measurement, thereby and the driving force required for the movement and the robot hand. Alternatively, the simulation result 311 including the motion trajectory through which the robot arm passes and the interference determination information regarding the interference with the surrounding environment during the motion activation is output.

The learner 302 inputs these simulation results 311, extracts efficient movements satisfying a certain criterion and movements without interference based on the evaluation function, and drives their movement trajectories and movements necessary for the movements. Information 312 regarding robot motion trajectory candidates and motion parameter constraints is output as information regarding force. Here, the motion parameter constraint is a condition for narrowing the allowable search space such as the joint movable range of the robot and the movable range of the robot expressed in Cartesian coordinates, or an upper limit for narrowing the upper limit of the acceleration / deceleration of the drive shaft. is there.

The 3D model simulation unit 301 uses the first approach trajectory candidate 313 and the second approach trajectory candidate 313 based on the information 312 and the gripping point candidates obtained based on the measurement data of the target object acquired by the camera or the like during the actual work. The approach orbit candidate 314 is generated and output. In addition, the 3D model simulation unit 301 sets the first approach trajectory candidate 313 based on the information 312 and the gripping point candidate obtained in the virtual environment by performing imaging processing on the simulation using the camera model in the virtual environment. It is also possible to generate and output the second approach orbit candidate 314. The first approach orbit candidate 313 is stored in the first approach orbit candidate storage unit 303, and the second approach orbit candidate 314 is stored in the second approach orbit candidate storage unit 304. Since the simulation unit 301 can perform the simulation in advance as many times as the calculation processing capacity allows, based on the object arrangement and the gripping point candidates assuming the situation assumed by the actual robot, the first approach The orbit candidate 313 and the second approach orbit candidate 314 can be stored in advance in a form corresponding to the positional relationship between all the gripping point candidates and the surrounding environment. That is, when the robot actually operates, based on the output information of the effective grip point candidate 21a, the first approach trajectory candidate generation unit considering the grip success rate and the interference with the surroundings is the first in a short time. The approaching orbit of 1 can be output. Similarly, the second approach orbit generator can output the second approach orbit in a short time.

The first approach orbit generation unit 22 selects the first approach orbit candidate 313 corresponding to the effective gripping posture 21a from the first approach orbit candidate storage unit 303, and selects the selected first approach orbit candidate 313. , Output as an effective first approach orbit 22a. The second approach orbit generation unit 23 selects the second approach orbit candidate 314 corresponding to the effective first approach orbit 22a from the second approach orbit candidate storage unit 304, and selects the second approach orbit. Candidate 314 is output as the second approach orbit 23a.

As described above, according to the interference avoidance device according to the seventh embodiment, in addition to the effect of the first embodiment, the processing time for executing the operation plan is shortened, and the tact time at the time of production is shortened. can get.

The configuration shown in the above-described embodiment shows an example of the content of the present invention, can be combined with another known technique, and is one of the configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

1,1A measurement unit, 1a measurement data, 2 interference avoidance device, 2a interference avoidance trajectory, 3,8 robot control device, 3a model information, 3b robot program, 3c setting information, 4 robot, 5 information integrated terminal, 6 conveyor control Equipment, 7 Processing machine control device, 9 parts box, 9a, 9a1, 9b parts, 9a11 longitudinal piece, 9a12 short piece, 9b1 protrusion, 10 grip point candidate generator, 10a, 10b, 17 grip point candidate, 11, 11A, 11B, 11C, 11D, 11E Orbit calculation unit, 12 convex part, 13 first approach orbit, 13a, 13a1, 13a2 first approach orbit element, 13a2a, 13b1a endpoint, 13b, 13b1, 13b2 second approach Orbital elements, 14 ideal approach direction, 15 permissible approach direction, 18 permissible progress vector, 19 permissible withdrawal vector, 21 gripping posture generator, 21a effective gripping posture, 22, 22A, 22B first approach trajectory generator, 22a effective first 1 approach orbit, 23, 23A, 23B 2nd approach orbit generation unit, 23a 2nd approach orbit, 24 avoidance orbit generation unit, 25 interference check unit, 26 interference risk evaluation unit, 27 assembly posture candidate generation unit, 27a Effective assembly posture candidate, 28 assembly position candidate generator, 28a assembly position candidate, 30a approach speed, 30b approach distance, 31a speed upper limit, 31b threshold, 32 virtual external force, 33 hand opening / closing speed, 34 hand opening / closing time, 41 arm , 42 tool part, 43,43-1,43A, 43B, 43C hand part, 43-1a suction pad, 44 jig, 50 floor surface, 60 program, 61 CPU, 62 ROM, 63 RAM, 65 input part, 66 bus Line, 70 fixed base, 80 fixed part, 81,82 intermediate goal information, 83,85 track element generation part, 84,86 approach track generation part, 87 gripping posture information, 88 first assembly posture candidate, 91 bottom part, 92a, 92b Surface measuring unit, 93 Top surface, 94 Opening, 100 Robot system, 101 Robot hand model, 102 Peripheral equipment model, 103 Tool model, 200 Production system, 300 Simulation unit, 301 3D model simulation unit, 302 Learner, 303 First approach orbit candidate storage unit, 304 Second approach orbit candidate storage unit, 311 Simulation result, 312 information, 313 First approach orbit candidate, 314 Second approach orbit candidate, 1001, 1002 Image processing apparatus.

Claims (8)

It is an interference avoidance device that prevents the tool unit having an openable / closable hand unit provided on the arm unit of the robot from interfering with the peripheral device by inputting measurement data that measures at least the state of the peripheral device.
Based on the measurement data and model information of the robot and the peripheral device, a grip point candidate generation unit that calculates a plurality of grip point candidates that the tool unit can grip the grip target of the tool unit.
A trajectory calculation unit for calculating an interference avoidance trajectory in which the tool unit approaches the grip target without interfering with the peripheral device based on the plurality of grip point candidates is provided.
The orbit calculation unit
A gripping posture generating unit that generates a plurality of gripping posture candidates existing within an allowable posture range without the tool unit interfering with the peripheral device for the plurality of gripping point candidates.
As the generated target posture of the gripping posture candidate, the tool unit can approach the target posture while the spatial movement constraint is generated so that the gripping object cannot rotate due to the relationship between the gripping object and the tool unit. A plurality of gripping postures capable of generating approaching orbits are extracted , and a plurality of orbits having each gripping posture as an end point are taken into consideration in consideration of the gripping approach constraint including the hand opening / closing speed and the hand opening / closing time of the hand portion . The first approach orbit generation unit generated as an approach orbit,
A second approaching trajectory in which the robot arm portion and the tool portion approach the first end point of the first approaching trajectory at the position farthest from the gripping object without interfering with the peripheral device. A second approach orbit generator that generates
A trajectory capable of reducing the waiting time for approaching the gripping object in consideration of the gripping approach constraint was selected from a plurality of first approaching orbits generated by the first approaching trajectory generating unit. An interference avoidance device including an avoidance trajectory generating unit that generates the interference avoidance trajectory that connects the first approach trajectory and the second approach trajectory. The orbit calculation unit
A first storage unit that stores a plurality of the first approaching orbits,
A second storage unit that stores a plurality of the second approaching orbits,
With more
The first approach orbit generation unit selects and outputs the first approach orbit corresponding to the gripping posture candidate from the first storage unit, and outputs the first approach orbit.
The second approach orbit generation unit selects and outputs the second approach orbit corresponding to the first approach orbit selected by the first approach orbit generation unit from the second storage unit. The interference avoidance device according to claim 1. The distance between the tool unit and the peripheral device is calculated based on the measurement data or the model information, and the distance and the approach speed thereof are used to determine the ease of interference of the tool unit with the peripheral device. Equipped with an interference risk evaluation unit to evaluate
The second approach orbit generation unit is not smaller than the distance at which the evaluation is a reference value from the orbit connecting the first end point of the first approach orbit and the gripping approach start point of the tool unit. Moreover, the second approach trajectory that does not become larger than the approach speed is selected , and the damage level of the object is set to a low speed based on the approach distance between the peripheral device and the robot and the approach speed between the peripheral device and the robot. The interference avoidance device according to claim 1, wherein the command value is adjusted . The second approach orbit generation unit applies a virtual external force, which is a repulsive force according to the distance, to the tool unit to modify the reference orbit using the potential method with the second approach orbit as the reference orbit. The interference avoidance device according to claim 3 , characterized in that. The second approach trajectory generating unit maximizes the approach speed of the tool unit to the gripping object, which changes according to the distance, within a range not exceeding the upper limit value of the approach speed. Item 3. The interference avoidance device according to item 3 . The first approach trajectory generating unit is a transit point of the trajectory defined between the target position of the tool unit and the gripping approach start point of the tool unit indicating a position separated from the target position of the tool unit by a certain distance. M + 1 first approach orbital elements connecting the M intermediate goals, the gripping approach start point, and the gripping point candidate are generated, and the generated plurality of first approaching orbital elements are connected.
The interference avoidance device according to any one of claims 1, 3, and 4 , wherein M is an integer of 1 or more. The second approach trajectory generating unit includes N intermediate goals, which are transit points of the trajectory defined between the grip approach start point and the picking operation start point, the grip approach start point, and the picking. Generate N + 1 second approach orbital elements that connect to the starting point of the motion, and connect the generated second approach orbital elements.
The interference avoidance device according to claim 6, wherein N is an integer of 1 or more. It is an interference avoidance device that prevents the tool unit having an openable / closable hand unit provided on the arm unit of the robot from interfering with the peripheral device by inputting measurement data that measures at least the state of the peripheral device.
Based on the measurement data and the model information of the robot and the peripheral device, a plurality of assembly positions in which the tool unit completes the assembly of the gripping object by using the gripping posture information of the tool unit with respect to the tool unit to be gripped. A trajectory calculation unit is provided that calculates candidates and calculates an interference avoidance trajectory in which the tool unit approaches the assembly target without interfering with the peripheral device based on the calculated plurality of assembly position candidates.
The orbit calculation unit
An assembly posture candidate generation unit that generates a plurality of assembly posture candidates existing within an allowable posture range without the tool unit interfering with the peripheral device with respect to the assembly position candidate.
From the generated plurality of assembly posture candidates, a plurality of assembly track candidates for extracting an assembly posture in which the tool unit can approach the assembly target without shifting the assembly target and forming the extracted assembly posture candidates. Is generated , and a plurality of orbits having each of the plurality of assembly posture candidates as an end point are generated as the first approach orbit while considering the gripping approach constraint including the hand opening / closing speed and the hand opening / closing time of the hand portion . 1 approach orbit generator and
A second approaching trajectory in which the robot arm portion and the tool portion approach the first endpoint point of the first approaching trajectory, which is the farthest position from the assembly target, without interfering with the peripheral device. A second approach orbit generator that generates
A trajectory capable of reducing the waiting time for approaching the gripping object in consideration of the gripping approach constraint was selected from a plurality of first approaching orbits generated by the first approaching trajectory generating unit. avoidance trajectory generation unit that generates the interference avoidance path that connects the second approach track and the first approach trajectory,
With
The first approach trajectory generating unit is defined between an assembly posture candidate which is a target position of the tool unit and a gripping approach start point of the tool unit which indicates a position separated from the target position of the tool unit by a certain distance. M + 1 first approaching orbital elements connecting the M intermediate goals, the assembly operation start point, and the gripping point, which are the waypoints of the orbits, are generated, and the generated plurality of first approaching orbital elements are generated. Connect and
The second approach trajectory generating unit includes N intermediate goals, which are transit points of the trajectory defined between the assembly operation start point and the start point of the entire assembly operation, the assembly operation start point, and the assembly operation start point. Generate N + 1 second approach orbital elements that connect to the starting point of the entire assembly operation, and connect the generated second approach orbital elements.
An interference avoidance device, wherein M is an integer of 1 or more, and N is an integer of 1 or more.

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