JP2007136588A - Programming pendant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a programming pendant which facilitates teaching of a control parameter of a physical contact force etc. associated with a command in an actual line, of a command row created on an off-line basis. <P>SOLUTION: The programming pendant 7 carries out teaching to a robot 1 having a power sensor 2 on a hand, for carrying out assembling work by bringing both component parts 4, 5 into contact transition with each other, and to a control device 11 having an impedance control section 13 to which an output from the power sensor 2 is fed back, for controlling the robot 1. In this case, the programming pendant 7 includes a reaction presenting means 10 for transferring a contact reaction between the component parts to the teaching operator as a tactual sense, a reaction control means 16 for issuing an operation command based on output from the power sensor 2, to the reaction presenting means 10, and an adjusting means 9 for adjusting the control parameter of an impedance control section 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a robot programming pendant.

Conventional robot teaching methods include a method using a teaching device called a programming pendant and a method using an offline program.
A method using a teaching device called a programming pendant teaches a position of a work in a work space as time series data. In such a method, since the robot simply executes time series data taught, it is impossible for the robot to automatically generate an operation procedure or an operation program online in response to a work change.
The offline program method is to program the robot operation in the robot language in consideration of the contact state transition between components found in the assembly work. In such a method, it is necessary to analytically count all the contact states between parts and the transitions between each contact state, and if the part shape changes, the transition between each contact state is counted from the beginning. It needs to be recreated. Therefore, the method using the offline program has a problem that work efficiency is poor and a burden is imposed on a worker who performs the program. Therefore, in recent years, a method for automatically generating a program (robot command) necessary for robot operation from teaching information obtained by human demonstration has been proposed (see, for example, Non-Patent Document 1).
Also, a robot teaching method (for example, Patent Document 1) is proposed in which a robot command sequence that describes minute operations such as contact state transitions found in assembly work can be generated online only by demonstrating the work. ing. This teaching method will be specifically described with reference to FIG. First, a contact state between a set of corners of an assembly part and a part to be assembled is classified into a predetermined type, and a local model is generated that symbolically represents a contact state transition between parts (ST1). Subsequently, the work space represented by the local model is geometrically divided (ST2). Next, the operator operates an assembly part and performs a demonstration (demonstration) of the assembly work (ST3). Demonstration of assembly work is performed manually using a data glove in a virtual reality environment on computer graphics, or using a camera measurement device, a three-dimensional pointing device, or direct teach in a real environment. . During such a demonstration, the time change data of the position of the assembly part on the divided work space and the time change data of the contact state between the parts are extracted and stored as teaching information (ST4). Then, by analyzing the stored teaching information, a model of contact state transition between the corners of the assembled part and the part to be assembled that is referred to when planning the robot operation is configured as a set of local models (ST5).
Y. Kuniyosi, H. Inaba and M. Inaba "Design and Implementation of a System that Genarates Assembly Programs from Visual Recognition of Human Action Sequence", Proc. IEEE Int. Workshop Intelligent Robots and Systems, pp.567-574, 1990 JP-A-9-198121

As described above, the conventional programming pendant is directed only to position teaching, and it is difficult to teach work involving a contact state transition such as assembly work. For this reason, offline programming teaching has been proposed, but in all cases, the conventional offline programming teaching method only creates a command sequence based on visual information, and the contact force that becomes a problem during actual state transitions. The problem of teaching physical interaction force, such as the size of, could not be solved. In other words, it is possible to extract the command sequence of the work sequence from the geometric information, but there is no means to teach physical information such as reaction force information required at the time of transition of the contact state. It has become necessary to adjust control parameters on a trial and error basis, making it difficult to apply in actual work sites.
The present invention has been made in view of such problems, and an object of the present invention is to control a physical contact force or the like associated with a command on an actual line in a command sequence generated off-line. An object is to provide a programming pendant capable of easily teaching parameters.

In order to solve the above problems, the present invention is configured as follows.
According to the first aspect of the present invention, a robot that performs assembly work by bringing a component held by the arm hand into contact with a component to which the component is assembled is based on an output of a force sensor provided on the hand. An impedance control unit that generates a target position correction amount of the arm, and is connected to a control device that feedback-controls the arm to a position obtained by adding the target position correction amount to previously taught teaching data. In a program pendant for operating the robot by sending an operation command inputted by depressing command input means during teaching to the control device, the programming pendant presents a reaction force that performs an operation according to the output from the force sensor Means, and an output of the force sensor, a reaction force control means for sending the operation command to the reaction force presenting means, and the impedance It is a programming pendant that is connected to the dance control unit and includes parameter adjustment means for changing the control parameter of the impedance control unit.
According to a second aspect of the present invention, in the programming pendant according to the first aspect, the command input means includes a plurality of contact switches, and the reaction force presentation means is provided immediately below each of the plurality of contact switches. To do.
In the invention according to claim 3, the reaction force presentation means is included in the coil bobbin that supports the contact switch from below, a coil wound around the lower part of the coil bobbin, and the coil. The programming pendant according to claim 2, wherein the voice pendant motor comprises an inner yoke provided, a magnet provided on the outer periphery of the coil, and an outer yoke provided further on the outer periphery of the magnet. .
In the invention according to claim 4, the reaction force control means sends a command for operating the reaction force presentation means to the reaction force presentation means based on the amplitude of the force output from the force sensor. The programming pendant according to item 1.
In the invention according to claim 5, the reaction force control means sends a command for operating the reaction force presenting means to the reaction force presenting means based on a frequency of force output from the force sensor. The programming pendant according to item 1.
According to a sixth aspect of the present invention, the reaction force presenting means includes a fixed portion provided inside the programming pendant, a rotary motor supported by the fixed portion, and an output shaft of the rotary motor. The programming pendant according to claim 1, comprising a load fixed eccentrically.

According to the first aspect of the present invention, the teaching worker can sense the contact force between parts via the programming pendant, and can finely adjust the parameter of the force control without looking at the programming pendant. Is possible.
According to the second aspect of the present invention, since the reaction force can be directly detected from the command input means, the operability of the teaching worker can be remarkably improved, and the programming pendant can be downsized. .
According to the invention described in claim 3, since the reaction force presenting means can be reduced in size, the entire programming pendant can be reduced in size and the operability of the teaching worker is improved.
Further, according to the invention described in claim 4, it is possible to present a direct contact force on the finger of the teaching worker in accordance with the magnitude of the contact force, thereby preventing damage to the work target component. It becomes possible.
In addition, according to the invention described in claim 5, since not only the amplitude but also the vibration cycle changes, the range of the reaction force that can be presented can be widened, and a wide range of presentations can be made from a fine contact force to a large contact force. Thus, the parameter adjustment of the force control means can be performed efficiently and the optimum parameter adjustment can be performed.
In addition, according to the invention described in claim 6, since it is possible to present the reaction force by vibrating the entire programming pendant, it is possible to enlarge the contact force and present it to the teaching worker, and to set the parameter finely. Adjustment can be performed efficiently.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a configuration diagram of an entire robot system including a robot programming pendant according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a robot. A hand 3 is fixed to the tip of the robot 1 via a force sensor 2, and the hand 3 holds a first component 4. On the work table 6, a second component 5 having a hole 5a into which the first component 4 is inserted is installed. The robot 1 is controlled by a control device 11.

  The control device 11 includes a command generation unit 12 that generates a target command angle for each joint unit of the robot 1 based on an operation command from a programming pendant 7 described later, and force information of the force sensor 2 as force control means. Based on the impedance control unit 13 that generates a position correction amount so as to achieve the target force based on the target command angle generated by the command generation unit 12 and the addition value of the position correction amount generated by the impedance control unit 13 The position / speed control unit 14 performs feedback control as a target position, and the servo amplifier 15 performs current control according to the output of the position / speed control unit.

  The programming pendant 7 includes a command input means 8 for a teaching worker to input an operation command for the robot 1 to the control device 11, and the first part 4 gripped at the tip of the robot 1 is the second part. The reaction force presenting means 10 presents the reaction force when touching 5 as a tactile sensation to the teaching worker, and the reaction force control means 16 for controlling the reaction force presenting means 10.

Next, a more detailed configuration of the command input means 8 and the reaction force presentation means 10 of the programming pendant 7 will be described with reference to FIGS. FIG. 2 is a diagram in which only the parts related to the command input means 8 of the programming pendant 7 and the parameter adjustment means 9 of the reaction force presentation means 10 are clearly shown from the top, and other display devices which are conventional techniques are omitted. ing. The command input means 8 and the reaction force presentation means 10 are respectively composed of 51 to 62 depending on the operating axial direction.
As a representative, FIG. 3 shows a cross-sectional view of 55 of FIG. The reaction force presentation means 10 comprises a voice coil motor comprising an outer yoke 10e, a magnet 10c, a coil 10b, an inner yoke 10d, and a coil bobbin 10a made of a nonmagnetic material. A contact switch 10f is fixed on the upper surface of the coil bobbin 10a. Thus, since the command input means 8 and the reaction force presentation means are arranged on the same axis, it can be arranged as it is on a conventional programming pendant and can be made compact. . Moreover, since the command is stopped just by removing the finger immediately after the reaction force is felt, damage to the parts due to erroneous operation can be avoided.

  The drive command input to the reaction force presenting means 10 is generated by the reaction force control means 16. Specifically, the vibration pattern shown in FIG. 5 is generated based on the control process shown in FIG. In addition to the method of generating the vibration pattern so that the vibration amplitude Dh is proportional to the output of the force sensor 2, as shown in FIG. 4, the frequency is changed in proportion to the output of the force sensor 2, and a large contact force is generated. In this case, a high-frequency vibration pattern may be generated.

Next, the adjustment procedure of the control parameter of the impedance control unit 13 using the parameter adjustment means 9 which is the object of the present invention will be specifically described. First, the impedance model of the impedance control unit 13 is:
F = M x (··) + B x (·) + K x
However, F: Contact force which is the output of the force sensor 2
M: Inertia coefficient
B: Viscosity coefficient
K: a spring coefficient, and the inertia coefficient M, viscosity coefficient B, and spring coefficient K are adjusted by the parameter adjusting means 9 of the programming pendant 7. As shown in FIG. 2, the parameter adjusting means 9 further includes a parameter selection switch 9a, a push button 9b for increasing the value of the parameter selected by the selection switch 9a, and a push button 9c for decreasing the value. Composed.

  When adjusting the control parameters (M, B, K) when pressing the first part 4 shown in FIG. 1 against the second part 5, the teaching worker uses the command input means 56 of the programming pendant 7. The first part 4 gripped by the tip of the robot 1 is moved closer to the second part 5 and pressed. At that time, the reaction force presenting means 10 vibrates according to the contact force, and the reaction force is transmitted to the teaching worker as a tactile sense. When the teaching worker determines that the reaction force is too large, the command input means 55 once separates the first part 4 and the second part 5, adjusts them with the parameter adjusting means 9, and again sets the programming pendant 7. The command input means 56 is impressed and adjusted until a desired reaction force is obtained, and parameters adjusted using the function of a conventional programming pendant are stored.

  Next, the configuration of the programming pendant 7 of the robot showing the second embodiment is shown in FIG. In FIG. 6, the rotary motor 17 is fixed via the programming pendant 7, the fixed portion 7a, and the fixed portion 7b. An eccentric load 19 is fixed to the output shaft 18 of the rotary motor 17. When the first component 2 comes into contact with the second component 5 and a contact force is generated, a drive command proportional to the contact force is input from the reaction force control means 16 to the rotary motor 17 and the eccentric load As a result, the vibration shown in FIG. 6 is generated in the programming pendant 7, and the contact force can be presented to the teaching worker. In this case, it is not necessary to generate a vibration pattern by the reaction force control means 16 as in the first embodiment, and a vibration pattern corresponding to the contact force can be generated by the rotation of the rotary motor 17. Further, by changing the weight of the eccentric load 19, the magnitude of the reaction force to be presented can be freely adjusted, and can be adjusted according to the type of application work, which is extremely useful in practice.

  As described above, it is possible to provide a programming pendant that can easily teach control parameters such as physical contact force associated with a command on an actual line in a command sequence generated off-line. it can.

The figure which shows the whole structure which uses the programming pendant of this invention Example 1. Part of the top view of the programming pendant of the present invention Partial sectional view explaining command input means and reaction force presentation means The figure explaining reaction force control means The figure explaining the operation pattern of reaction force presentation means Part of top view of programming pendant of embodiment 2 of the present invention Conventional robot teaching method

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Robot 2 Force sensor 3 Hand 4 1st part 5 2nd part 5a Hole 6 Work table 7 Programming pendant 8 Command input means 9 Parameter adjustment means 9a Parameter selection switch 9b Push button 9c Push button 10 Reaction force presentation means 10a Coil bobbin 10b Coil 10c magnet 10d inner yoke 10e outer yoke 10f contact switch 11 control device 12 command generation unit 13 impedance control unit 14 position / speed control unit 15 servo amplifier 16 reaction force control means 17 rotary motor 18 output shaft 19 eccentric load
7a Fixed part
7b Fixed portion 51 X + direction command input means 52 X− direction command input means 53 Y + direction command input means 54 Y− direction command input means 55 Z + direction command input means 56 Z− direction command input means 57 RX + direction command input means 58 RX -Direction command input means 59 RY + Direction command input means 60 RY-Direction command input means 61 RZ + Direction command input means 62 RZ-Direction command input means

Claims (6)

A robot that performs assembly work by bringing a component held by the arm's hand into contact with a component to which the component is assembled is adjusted based on the output of a force sensor provided on the hand. An impedance control unit for generating, connected to a control device that feedback-controls the arm to a position obtained by adding the target position correction amount to previously taught teaching data, and the operator presses the command input means during teaching In a program pendant that sends the input operation command to the control device to operate the robot,
The programming pendant includes a reaction force presentation unit that performs an operation according to an output from the force sensor, and a reaction force control unit that receives the output of the force sensor and sends a command of the operation to the reaction force presentation unit. A programming pendant comprising: parameter adjusting means connected to the impedance control unit and changing a control parameter of the impedance control unit.   2. The programming pendant according to claim 1, wherein the command input means includes a plurality of contact switches, and the reaction force presentation means is provided immediately below each of the plurality of contact switches.   The reaction force presenting means includes a coil bobbin that supports the contact switch from below, a coil wound around the lower part of the coil bobbin, an inner yoke provided so as to be included in the coil, and an outer periphery of the coil 3. The programming pendant according to claim 2, wherein the voice pendant motor comprises: a magnet provided on the magnet and an outer yoke provided on the outer periphery of the magnet.   2. The programming pendant according to claim 1, wherein the reaction force control means sends a command for operating the reaction force presenting means to the reaction force presenting means based on the amplitude of the force output from the force sensor. .   2. The programming pendant according to claim 1, wherein the reaction force control means sends a command for operating the reaction force presenting means to the reaction force presenting means based on the frequency of the force output from the force sensor. .   The reaction force presentation means includes: a fixed portion provided inside a programming pendant; a rotary motor supported by the fixed portion; and a load that is eccentrically fixed to the output shaft of the rotary motor. The programming pendant according to claim 1, wherein

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