JP2005001055A - Robot device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a robot device which stores liquid and powder, etc. into a container and efficiently carries the liquid and powder, etc. without spilling them from an opening of the container. <P>SOLUTION: The container is held by a hand mounted at a distal end of a robot arm to carry the liquid and powder, etc. stored into the container. The attitude of the container is directed in the same direction (just under) as that of gravitational acceleration vector when starting the carrying. As acceleration is increased in an acceleration process, inertia acceleration vector is gradually increased, and inclination is increased in an opposite direction of the direction of the acceleration. When the acceleration is changed to a decrease, the inertia acceleration vector is gradually decreased and the inclination is reduced. When the acceleration process is completed and speed becomes constant, the inclination is eliminated. In a deceleration process, the inclination is increased in the direction opposite to that in the acceleration process as deceleration is increased. When the deceleration is changed to a decrease, the inclination is reduced. When a robot stops, the inclination is eliminated and the container is returned to the attitude directed to the just under direction when starting the carrying. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a robot (a main body having a motion mechanism) and a robot apparatus including a control device for controlling the robot, and more particularly, a liquid, powder, or a small-sized molded product (for example, a small-sized screw). ) And the like are related to a robot apparatus that conveys them in a state where they are accommodated in a container (bucket or the like). In this specification, “container” refers to a container having an opening, such as a bucket, and excludes a sealed container.
[0002]
[Prior art]
When transporting a liquid, powder, or a collection of extremely small objects in a container by a robot, the liquid surface, powder surface, or top surface of a small object shakes due to acceleration while the robot is moving. Spill out of container. Conventionally, in order to prevent this, only a liquid, powder or small-size object which is considerably smaller than the maximum capacity of the container can be transported, and the transport efficiency is low. Moreover, it is necessary to reduce the speed and acceleration at the time of movement so that these objects are not spilled out of the container, and the cycle time is also long.
[0003]
As a technique for avoiding such a drawback, there is a method in which a handle that allows a change of one degree of freedom with respect to the inclination of the container is attached to the container, and the robot supports and conveys the container through this handle. Since the posture change is one degree of freedom, it is effective only during conveyance in a specific movement direction. In addition, the container may swing when the robot is stopped, etc., and it is necessary to set the speed and acceleration low so that liquid or the like does not spill.
[0004]
Although it is conceivable to attach a handle with two degrees of freedom, even in such a case, when the jerk (rate of change of acceleration) is large, there is a high possibility that liquid or the like will spill.
[0005]
Furthermore, there is the following Patent Document 1 as a prior art related to the present invention. This uses a hand that has a gripping force that is asymmetric with respect to the direction of movement in order to grip a long-axis pipe, etc., and has a large gripping force with respect to acceleration, taking into account only the inertial force applied to the workpiece. It controls the posture of the hand in the direction. This prior art is an invention that relies on a hand having a specific asymmetric gripping force, which considers inertial force but does not consider gravity, and is difficult to apply to transporting liquids, powders, etc. is there.
[0006]
[Patent Literature]
Japanese Patent Laid-Open No. 9-300255
[0007]
[Problems to be solved by the invention]
As described above, a robot can be used efficiently without spilling in a state where a transported object having fluidity or a property similar to that such as a liquid, powder, or a collection of extremely small objects is contained in a container. It cannot be said that the development of the transport technology is sufficiently advanced. Therefore, an object of the present invention is that the object to be transported accommodated in a container supported by the robot has fluidity or a property similar to it, such as a collection of liquids, powders, or small-sized objects. Another object of the present invention is to provide a robot apparatus that can efficiently convey the container without spilling it.
[0008]
[Means for Solving the Problems]
The present invention takes into account the inertial acceleration vector applied in the opposite direction of the acceleration direction to the heavy acceleration vector applied to the transferred object when the transferred object is transferred in the state of being accommodated in the container. Then, a combined vector of the gravity acceleration vector and the inertial acceleration vector is calculated, and using the direction of the combined acceleration vector as an index, an appropriate transport posture (hereinafter also referred to as “appropriate transport posture”) is obtained, and the proper transport posture is calculated. The above technical problem is solved by controlling the posture of the robot so that is realized.
[0009]
Here, the “appropriate transport posture” is a robot posture calculated based on the direction of the resultant acceleration vector from the viewpoint of preventing the transported object from spilling from the container. However, this “robot posture” has a one-to-one correspondence with the posture of the “container” that accommodates the object to be transported or the posture of the robot hand that holds the container (when the container is gripped by the robot hand). . Therefore, obtaining the proper transport posture of the robot is substantially equivalent to obtaining the proper transport posture for the container or the hand.
[0010]
The present invention includes a robot that transports a transported object placed in a container from a transport start position to a transport end position so that the transported object does not spill from the container, and a control device that controls the robot. Applies to robotic devices. In accordance with the basic feature of the present invention, the robot device synthesizes the inertial acceleration vector and the gravitational acceleration vector by means of calculating means for calculating an inertial acceleration vector applied to the object being conveyed at predetermined intervals. Means for determining an acceleration vector; means for determining an appropriate transfer posture of the robot during transfer based on the determined combined acceleration vector; and means for controlling the posture of the robot based on the determined appropriate transfer posture It has.
[0011]
The robot posture is controlled to change following the change in the direction of the combined acceleration vector. For this purpose, the means for obtaining the difference between the direction of the combined acceleration vector and the direction of the gravitational acceleration vector and the robot whose posture has been changed by an amount corresponding to the difference with reference to the posture of the robot at the transfer start position. Means for obtaining an appropriate transport posture is provided in the robot apparatus.
[0012]
Means for obtaining the posture change amount of the robot corresponding to the difference between the direction of the synthesized acceleration vector in the previous cycle and the direction of the synthesized acceleration vector obtained in the current cycle, with the initial value of the synthesized acceleration vector as the gravitational acceleration vector And the appropriate transfer posture of the robot at the transfer start position as an initial value of the transfer posture of the robot, and the appropriate transfer posture obtained in the previous cycle is changed by the posture change amount, and the proper transfer posture in the current cycle May be provided, and the posture of the robot may be controlled based on the obtained proper transport posture.
[0013]
The inertial acceleration vector for each predetermined cycle can be calculated based on the conveyance start position, the conveyance end position, and the speed command given by the command program, and a predetermined acceleration / deceleration process. Or you may make it obtain the inertial acceleration vector in conveyance from the measurement means of the inertial acceleration vector provided in the said container or its vicinity.
For example, when transporting an empty container, select a mode that does not perform posture control of the robot based on the appropriate transport posture according to the command of the command program in order to cope with cases where there is no fear of spilled objects. It is preferable to be able to do this.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic layout diagram showing a state of conveyance by a robot apparatus according to an embodiment of the present invention. Reference numeral 1 denotes a robot (main body mechanism unit) that carries a robot, and a robot hand (hereinafter simply referred to as “hand”) 2 that holds the container 3 is attached to the tip of the arm. The robot 1 is connected to a robot control device 5 and its operation is controlled by the robot control device 5. The container 3 is for containing a material to be conveyed having fluidity or a property equivalent thereto, such as a liquid, powder, or a collection of small-sized objects, and a bucket is used here.
[0015]
The container 3 is provided with an opening 4 for taking in and out the object to be conveyed. In the state shown in FIG. 1, the opening 4 is directed right above. Hereinafter, such an attitude of the container (an attitude in the space) will be referred to as a “(container) reference attitude”. Further, the posture of the hand 2 (that is, the posture of the robot 1) that causes the container 3 to take the reference posture is referred to as “(robot) reference posture”. In a general case, “the attitude of the container in which the transported object with fluidity is not easily spilled while the robot supporting the container is stationary” may be considered as the “reference attitude of the container”.
[0016]
Then, as a vector representing the attitude of the container 3 in the space, a unit vector that faces in the vertically downward direction when the container 3 is in a stationary state and is in a reference attitude is considered as a vector H. The vector H is a vector fixed on the container 3 to the hand 2, and if the container 3 to the hand 2 is inclined, it naturally follows the inclination.
[0017]
The arrow S shown in FIG. 1 shows an example in the transport direction. If the robot 1 operates and the hand 2 moves in the direction of the arrow S, the object to be transported in the container 3 is naturally the arrow S. It is conveyed in the direction of. When performing such a transfer, the robot 1 is accelerated for a while after starting from the transfer start position, and decelerated before the command transfer end position. As a result, the object to be transported in the container 3 becomes unstable. For example, when the object to be transported is a liquid, a phenomenon occurs that the liquid level 6 falls and spills out from the opening 4 of the container 3.
[0018]
As described above, in the present invention, this phenomenon is controlled by the attitude control of the container being transported (direction control in the space of the vector H), in other words, the attitude control of the robot hand holding the container (more generalized). In other words, it is avoided by controlling the attitude of the robot that supports the container. This posture control is performed so that the direction of the vector H changes following the change of the direction of “total acceleration received by the conveyed object”.
[0019]
When the robot 1 is stationary and moved in a constant direction and constant speed, gravity Mg acts on the object to be transported in the container 3 in the downward direction. The acceleration vector corresponding to the gravity Mg is represented by the gravity acceleration vector Ka. On the other hand, during acceleration / deceleration (accelerating or decelerating; hereinafter the same), inertial force is applied thereto. FIG. 2 shows this state. As shown in FIG. 2, the inertia force has the magnitude of the product of the vector a representing acceleration and the mass M, and the direction is opposite to that of the vector a. This inertial force is represented by -Ma, and the acceleration corresponding to this inertial force is represented by an inertial acceleration vector Ka. A force obtained by combining the gravity Mg and the inertial force -Ma is represented by Mh, and an acceleration corresponding to the combined force is represented by a combined acceleration vector Kh.
[0020]
Here, the gravitational acceleration vector Kg can be determined from a known gravity constant and data of a set coordinate system (for example, the −Z axis direction of the world coordinate system). As will be described later, the inertial acceleration can be obtained by calculation from data held by the robot, but can also be obtained by using an acceleration sensor. In that case, the acceleration sensor is installed on the container 3 as indicated by reference numeral 8 or is installed in the vicinity of the container 3 such as the hand 2 as indicated by reference numeral 9, and is detected at each calculation cycle by the robot controller 5. Send a signal.
[0021]
Now, if the inertial force -Ma acts on the liquid, powder, etc., it will move in the container 3 in an attempt to be distributed in the direction of the inertial acceleration vector Ka and become unstable. Therefore, if the posture of the container 3 (that is, the posture of the hand 2 or the posture of the robot 1; the same applies hereinafter) is maintained in the standard posture (see FIG. 1), the liquid, powder, etc. The conveyed product is easily spilled from the opening 4.
[0022]
Therefore, in the present invention, the posture of the container 3 is changed so as to follow the change in the direction of the combined acceleration vector Kh to prevent the conveyed object from spilling out of the container 3. In this embodiment, as shown in FIG. 3, the vector H representing the attitude of the container 3 (or hand 2) is an angle Θ from the direction of the gravitational acceleration vector Kg (ie, the direction of the resultant acceleration vector Kh at rest). The robot 1 is controlled so as to incline and coincide with the direction of the resultant acceleration vector Kh at that time (the direction in which the resultant force Mh acts).
[0023]
In other words, the angle Θ is the angle formed by the resultant acceleration vector Kh during conveyance with the direction of the gravitational acceleration Mg (ie, the direction of the resultant acceleration vector Kh at rest) (ie, the resultant acceleration vector Kh generated by the inertial acceleration vector Ka 1). This is an angle representing a change in direction.
[0024]
Thus, by controlling the posture of the container 3 or the hand 2 in the direction of the combined acceleration vector Kh, the combined acceleration (synthetic force) always acts on the bottom surface of the container 3 in the vertical direction even during the conveyance. In addition, liquids, fluids, etc. can be transported without spilling. 4 and 5 are diagrams for explaining the transition of the posture of the container 3 to the hand 2 in the case where the robot moves with a typical transition of speed and acceleration, and FIG. 4 shows the program speed from the acceleration immediately after the start of conveyance. FIG. 5 shows the posture transition of the container or the hand in the process leading to the linear movement at the (command speed), and FIG. 5 shows the attitude of the container or the hand in the process of decelerating from the linear movement at the program speed (command speed) to the end of the conveyance. It represents the transition. In both figures, the arrow written for each posture represents the direction of the vector H described above.
[0025]
As can be seen from these figures, at the start of conveyance, the vector H is directly below (same direction as the gravitational acceleration vector), but as the acceleration increases during the acceleration process, the inertial acceleration vector gradually increases, When the inclination increases in the reverse direction (the same direction as the inertial acceleration vector) and the acceleration starts to decrease, the inertial acceleration vector gradually decreases and the inclination decreases. When the acceleration process is completed and the speed is constant (linear movement at the program speed), the inclination is canceled, and the vector H maintains the downward direction at the start of conveyance.
[0026]
Next, as the deceleration (acceleration in the direction of decreasing the speed) increases in the deceleration process, the inertial acceleration vector (opposite to the acceleration process) gradually increases, the slope increases in the opposite direction to the acceleration process, and the deceleration increases. If it starts to decrease, the inertial acceleration vector (opposite to the acceleration process) gradually decreases, and its inclination decreases. When the deceleration process is completed and the robot 1 is stopped, the inclination is canceled, and the vector H returns to the downward direction at the start of conveyance.
[0027]
Next, an example of a specific procedure for executing the attitude control as described above will be described. Note that the posture control of the container is performed through the posture control of the robot 1. In this embodiment, the container 3 is held by the hand 2, and the posture control of the robot 1 is to control the posture of the hand 2. Since this is none other than the above, “posture control of the robot 1” will be described as “posture control of the hand 2”.
[0028]
As described above, the robot 1 is connected to the robot control device 5 (see FIG. 1), and the posture control of the hand 2 in the above-described manner is performed by the robot control device 5. The hardware configuration of the robot control device 5 may be the same as that of the conventional robot control device, and the software configuration is not particularly different from the conventional configuration except for software for executing processing described later.
[0029]
Since the general configuration of the robot control device is well known, only the outline will be described very simply with reference to FIG. As shown in FIG. 6, the robot control device 5 drives a processor 51, a memory 52 including a ROM, a RAM, a display device 53, an input means 54 such as a key of a teaching operation panel, and each joint axis of the robot. Servo control means 55 for driving and controlling the servo motor, an input / output circuit 56 connected to peripheral devices of the robot, and the like.
[0030]
The processor 51 executes the teaching program stored in the memory 52 and outputs a movement command to the servo control means 55. The servo control means 55 performs feedback control of the position and speed of each axis based on this movement command, the position attached to the servo motor of each axis, the position from the speed detector, and the speed feedback signal. As a result, the position, posture, and speed of the grip point (TCP; tool tip point) of the hand 2 attached to the arm tip of the robot 1 (see FIG. 1) are controlled.
[0031]
Here, in the present embodiment, in order to realize the attitude control (the attitude control using the combined acceleration vector obtained by combining the inertial acceleration vector and the heavy force vector as a tracking index) in the above-described manner, 7 is executed.
[0032]
Note that immediately before the transfer operation is started, the container 3 is held by the hand 2 in a state in which an object to be transferred (for example, liquid) is accommodated, and the posture is in the reference posture (the posture in which the vector H described above faces directly below). Shall. From this state, a line having a teaching program (a line instructing conveyance from the conveyance start position to the conveyance end position) is read in the robot control device 5, and the operation from the current position to the end point described in the program execution line is performed. The process for starting is started. The main points of each step are as follows.
[0033]
Step A1: First, the movement amount Li and the movement time Tm per operation are calculated from the start and end positions of the operation and the program speed (command speed).
[0034]
Step A2: An index n representing the number of calculation cycles and a time index Tn are initialized to n = 1 and Tn = 0, respectively.
Step A3: A movement amount ΔLt = n from time Tn to time Tn + 1 is calculated, and the value is stored in the memory.
[0035]
Step A4: It is confirmed whether the hand posture control is valid. If it is valid, the flow proceeds to step A5 and subsequent steps in order to perform the hand posture control of the present invention. If invalid, the process proceeds to step A13. Whether or not the hand posture control is valid can be confirmed, for example, by checking a mode flag value (1 or 0) designated by a program command. Alternatively, the mode flag value may be set by the input means 54 (see FIG. 6) and checked by checking the mode flag value.
[0036]
Step A5: A speed ΔVt = n is calculated from the difference between the movement amounts ΔLt = n and ΔLt = n + 1. Further, acceleration ΔAt = n is calculated from the difference between the speed ΔVt = n and the speed ΔVt = n + 1. The initial values are ΔLt = 1 = 0 and ΔAt = 1 = 0.
Step A6: An inertial acceleration vector Ka is calculated from the acceleration ΔAt = n. Further, a gravitational acceleration vector Kg is calculated from the gravitational acceleration acting on the container. Note that the data on the magnitude of gravitational acceleration is previously set in a memory.
[0037]
Step A7: A combined acceleration vector Kh of the inertial acceleration vector Ka and the gravitational acceleration vector Kg is calculated.
Step A8: Hand postures (appropriate postures) Wh 1, Ph 2, Rh 1 that face the direction of the resultant acceleration vector Kh 1 are calculated.
Step A9: The amount of movement Δ of each motor from the positions X, Y, Z at time Tn, the hand postures W, P, R at time Tn, and the geometrical formula (for example, DH parameter) of the robot. M is calculated.
[0038]
Step A10: The movement amount ΔM of each motor is commanded to each motor, and the motor is operated.
Step A11: Wait for ΔT and set Tn = Tn + ΔT.
[0039]
Step A12: It is checked whether Tn ≧ Tm. If yes, the process ends. If no, return to Step A3 and repeat Step A3 to Step A12.
[0040]
Step A13: When it is determined in step A4 that the hand posture control is not effective, the hand posture control of the present invention is not performed, and the position at time Tn, the hand posture W, P, R, and The movement amount ΔM of each motor is calculated from the robot's geometric formula (for example, the DH parameter), and the process proceeds to step A10 and subsequent steps.
[0041]
Thereafter, after step A10 → step A11, the cycle of step A12 → step A3 → step A4 → step A13 → step A10 → step A11 → step A12 will be repeated as many times as necessary (until yes at step A12). . In addition, as a case where the robot is moved in this cycle, a case where the container 3 is empty or a case where only a small amount of objects to be conveyed is accommodated in the container 3 can be considered.
[0042]
In step A8 in the process of the flowchart of FIG. 7, hand postures Wh, Ph and Rh themselves (appropriate postures themselves at time Tn) facing the direction of the resultant acceleration vector Kh are calculated. In subsequent step A9, the proper postures are calculated. The motor movement amount ΔM to be realized is obtained from the positions X, Y, Z at the time Tn, the hand postures W, P, R at the time Tn, and the geometric formula of the robot.
[0043]
However, instead of the proper posture calculated in step A8 (the posture facing the direction of the combined acceleration vector Kh) itself, “the displacement amounts δW, δP, δR of W, P, R necessary for realizing the proper posture” May be calculated. This step is referred to as step B8. Here, the hand posture at the start of conveyance (Tn = 0) (the reference posture of the hand) can be employed as the posture (posture corresponding to δW = δP = δR = 0) as the starting point of the displacement amount calculation. . Alternatively, the “posture calculated when the combined acceleration vector is not considered” calculated in step A13 may be adopted as the posture corresponding to δW = δP = δR = 0. Such an attitude corresponding to δW = δP = δR = 0 is represented by W1, P1, and R1 for convenience.
[0044]
Then, as step B9 following step B8, a step of calculating postures W ′, P ′, R ′ obtained by adding the displacements δW, δP, δR to the postures W1, P1, R1 can be employed. The flowchart of FIG. 8 shows an outline of processing when these steps B8 and B9 are employed instead of steps A8 and A9. In the flowchart, Step B1 to Step B7 and Step B10 to Step B13 are the same as Step A1 to Step A7 and Step A10 to Step A13, respectively, and thus the description thereof is omitted. The main points of Step B8 and Step B9 are as described above.
[0045]
Furthermore, it is possible to adopt a processing method in which calculation is performed with an incremental amount for each calculation cycle including calculation of an appropriate posture. The outline of the process in that case is shown in the flowchart of FIG. The main points of each step are as follows.
[0046]
Step C1: A movement amount Li and a movement time Tm per operation are calculated from the start and end positions of the operation and the program speed (command speed).
Step C2: An index n indicating the number of calculation cycles and a time index Tn are initialized to n = 1 and Tn = 0, respectively.
[0047]
Step C3: A movement amount ΔLt = n from time Tn to time Tn + 1 is calculated, and the value is stored in the memory.
Step C4: It is confirmed whether or not the hand posture control is effective, and if it is effective, the flow proceeds to Step C5 and subsequent steps in order to perform the hand posture control of the present invention. If invalid, the process proceeds to step C14.
[0048]
Step C5: A speed ΔVt = n is calculated from the difference between the movement amounts ΔLt = n and ΔLt = n + 1. Further, acceleration ΔAt = n is calculated from the difference between the speed ΔVt = n and the speed ΔVt = n + 1. The initial values are ΔLt = 1 = 0 and ΔAt = 1 = 0.
[0049]
Step C6: An inertial acceleration vector Kan is calculated from the acceleration ΔAt = n. Also, a gravitational acceleration vector Kgn is calculated from the gravitational acceleration acting on the container. The gravitational acceleration vector is substantially unchanged, and a set value is used for each calculation. However, for convenience, it is expressed as Mgn.
[0050]
Step C7: A combined acceleration vector Khn of the inertial acceleration vector Kan and the gravitational acceleration vector Kgn is calculated.
[0051]
Step C8: If the index n is n = 1 (corresponding to the start of conveyance), the process proceeds to Step C15, and if not, the process proceeds to Step C9.
[0052]
Step C9: Calculate the displacement amounts ΔW, ΔP, ΔR of W, P, R necessary for realizing the appropriate posture (the posture facing the direction of the combined acceleration vector Khn). Here, hand postures Wn−1, Pn−1, and Rn−1 calculated in the previous calculation cycle are adopted as postures that serve as starting points for displacement amount calculation (postures corresponding to ΔW = ΔP = ΔR = 0). To do.
[0053]
Step C10: Hand posture Wn = Wn-1 + .DELTA.W, Pn = Pn-1 + .DELTA.P, Rn = Rn-1 + .DELTA.R are calculated, and positions X, Y, Z at time Tn, and the geometrical formula of the robot. Thus, the movement amount ΔM of each motor is calculated.
[0054]
Step C11: The movement amount ΔM of each motor is commanded to each motor, and the motor is operated.
[0055]
Step C12: Wait for ΔT, and set Tn = Tn + ΔT.
[0056]
Step A13: It is checked whether Tn ≧ Tm. If yes, the process ends. If no, return to Step C3 and repeat Step C3 to Step C13.
[0057]
Step C14: If it is determined in step C4 that the hand posture control is not effective, the hand posture control of the present invention is not performed, and the position at time Tn, the hand posture W, P, R, and The movement amount ΔM of each motor is calculated from the geometrical formula of the robot (for example, DH parameter), and the process proceeds to Step C11 and the subsequent steps.
[0058]
After that, after step C111 → step C12, the cycle of step C13 → step C3 → step C4 → step A14 → step C11 → step C12 → step C13 is repeated as many times as necessary (until yes at step C13). .
[0059]
Step C15: If n = 1 is determined in step C8 (corresponding to the start of conveyance), the gravitational acceleration vector Kgn is adopted as the expected value of the combined acceleration vector vector Mhn.
[0060]
In the embodiment described above, the inertial acceleration is calculated from the acceleration ΔAt = n (see step A6, B6, or C6), but the inertial acceleration data can also be acquired using an acceleration sensor. In that case, the acceleration sensor is grounded on the container 3 (see reference numeral 8 in FIG. 1) or is installed in the vicinity of the container 3 such as the hand 2 (see reference numeral 9 in FIG. 1). Thus, the detection signal is taken in every calculation cycle, and the inertial acceleration vector may be obtained based on the detection signal.
[0061]
【The invention's effect】
According to the present invention, even if the object to be transported accommodated in the container and transported by the robot exhibits fluidity or a property equivalent thereto, such as liquid, powder, small size object, etc. Since the position of the container is controlled so that the object to be conveyed does not spill out from the container, even if it is transported while containing liquid, powder, etc. up to the maximum capacity of the container, it will be a problem. As a result, the transport efficiency per container is improved. In addition, it is possible to increase the speed and acceleration of the robot at the time of transportation, and it is possible to transport liquids, powders, small-sized objects, etc. in a short cycle time.
[Brief description of the drawings]
FIG. 1 is a schematic layout diagram showing a state of conveyance by a robot apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining acceleration received by an object in a container during conveyance.
FIG. 3 is a diagram illustrating posture control performed during conveyance.
FIG. 4 is a diagram for explaining a change in posture of a container or a hand in a process from acceleration immediately after the start of conveyance to linear movement at a program speed (command speed).
FIG. 5 is a diagram for explaining the posture transition of the container or the hand in the process from the start of deceleration to the stop of the robot.
FIG. 6 is a block diagram illustrating an outline of a configuration of a robot control device used in the embodiment.
FIG. 7 is a flowchart illustrating an outline of an example of processing executed in the embodiment.
FIG. 8 is a flowchart illustrating an outline of another example of processing executed in the embodiment.
FIG. 9 is a flowchart illustrating an outline of still another example of processing executed in the embodiment.
[Explanation of symbols]
1 Robot (Main body mechanism)
2 Robotic hand
3 containers
4 opening
5 Robot controller
6 Liquid level
8, 9 Acceleration sensor
51 processor
52 memory
53 Display device
54 Input means
55 Servo control means
56 I / O circuit
S Transfer direction (Robot movement direction)

Claims (6)

In a robot apparatus that includes a robot that transports a transported object placed in a container from a transport start position to a transport end position so that the transported object does not spill from the container, and a control device that controls the robot.
Means for calculating an inertial acceleration vector applied to the conveyed object being conveyed at predetermined intervals;
Means for combining the inertial acceleration vector and the gravitational acceleration vector to obtain a combined acceleration vector;
Means for determining an appropriate transfer posture of the robot during transfer based on the determined combined acceleration vector;
A robot apparatus comprising: means for controlling the posture of the robot based on the determined proper transport posture. In a robot apparatus that includes a robot that transports a transported object placed in a container from a transport start position to a transport end position so that the transported object does not spill from the container, and a control device that controls the robot.
Means for calculating an inertial acceleration vector applied to the conveyed object being conveyed at predetermined intervals;
Means for combining the inertial acceleration vector and the gravitational acceleration vector to obtain a combined acceleration vector;
Means for determining a difference between the direction of the combined acceleration vector and the direction of the gravitational acceleration vector;
Means for determining an appropriate transport posture of the robot that has undergone a posture change corresponding to the difference with reference to the posture of the robot at the transport start position;
A robot apparatus comprising: means for controlling the posture of the robot based on the determined proper transport posture. In a robot apparatus that includes a robot that transports a transported object placed in a container from a transport start position to a transport end position so that the transported object does not spill from the container, and a control device that controls the robot.
Means for calculating an inertial acceleration vector applied to the conveyed object being conveyed at predetermined intervals;
Means for combining the inertial acceleration vector and the gravitational acceleration vector to obtain a combined acceleration vector;
Means for determining a posture change amount corresponding to the difference between the direction of the synthetic acceleration vector in the previous cycle and the direction of the synthetic acceleration vector obtained in the current cycle, with the initial value of the synthetic acceleration vector as a gravitational acceleration vector;
Using the initial value of the robot transport posture as the appropriate transport posture of the robot at the transport start position, the proper transport posture obtained in the previous cycle is changed by the posture change amount to obtain the proper transport posture in the current cycle. Means,
A robot apparatus comprising: means for controlling the posture of the robot based on the determined proper transport posture. The inertial acceleration vector for each predetermined cycle is obtained based on a transfer start position, a transfer end position, a speed command given by the command program, and a predetermined acceleration / deceleration process. 4. The robot apparatus according to any one of 3. 4. The apparatus according to claim 1, wherein means for measuring an inertial acceleration vector is provided in or near the container in place of the means for calculating the inertial acceleration vector during conveyance. The robot apparatus as described in. The robot apparatus according to any one of claims 1 to 5, wherein a mode in which the posture control of the robot based on the proper transport posture is not performed can be selected by a command of a command program. .

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