Patent Publication Number: US-2004054439-A1

Title: Robot control apparatus, robot, and production facility

Description:
TECHNICAL FIELD  
       [0001] The present invention relates to a robot control apparatus, a robot and production facilities.  
       BACKGROUND ART  
       [0002] A robot is seldom used alone in the practical industrial application. Normally, it is equipped with, for example, a jig for handling works, or a device for transportation, welding, etc., or other types of tools such as a torch, and performs a certain specific task such as machining processing, welding, etc. in a series of production activities. For example, in a series of production activities, a conveyor carries a work to a place to be machined there and then to other place for welding.  
       [0003] In a production process as described above, in order to recognize state of operations being performed by peripheral devices a robot control apparatus gathers data which represents operating status of peripheral devices, via an input-output section of sequence controller.  
       [0004] Now in the following, an input-output section of a conventional robot control system formed of a robot control apparatus and a sequence controller is described.  
       [0005]FIG. 6 is a block diagram, showing an exemplary structure of conventional robot control apparatus.  
       [0006] Referring to FIG. 6, robot control apparatus  52  comprises a robot arm control unit  53  and sequence controller  55 . Robot arm control unit  53  and sequence controller  55  exchange signals to each other via bus  58 .  
       [0007] Robot arm control unit  53  controls robot main body  51 .  
       [0008] Sequence controller  55  controls peripheral devices  54  working in collaboration with robot main body  51 .  
       [0009] Sequence controller  55  includes control section  57  and input-output section  56 . Control section  57  exchanges signals with robot arm control unit  53  via bus  58 .  
       [0010] Input-output section  56  receives from peripheral devices  54  signals that represent a state of operation being carried out by peripheral devices  54 . Input-output section  56  also outputs and delivers control signals to peripheral devices  54  in accordance with state of operation being performed by robot main body  51 .  
       [0011] Control section  57  processes signals from peripheral devices  54  and signals from robot arm control unit  53 , and controls input-output section  56  and peripheral devices  54 .  
       [0012] Control section  57  and input-output section  56  exchange signals via bus  59 .  
       [0013] Input-output section  56  here performs a signal processing in accordance with an input-output mode of peripheral device  54 .  
       [0014] In an exemplary case of conventional robot control apparatus as described above, the input-output section of sequence controller is compelled to change the output mode to be compatible with respective input-output modes of peripheral devices, if the peripheral devices constituting a robot control system have different input-output modes.  
       [0015] In other words, when constituting a robot control system, the constituent peripheral devices have to be selected among those which have the same mode of input-output compatible with sequence controller; or, an appropriate sequence controller needs to be provided after confirming the input-output modes of respective peripheral devices.  
       DISCLOSURE OF INVENTION  
       [0016] The present invention aims to offer a robot control apparatus.  
       [0017] When structuring a robot control system using a robot and peripheral devices, the present robot control apparatus lessens limitations due to difference in the input-output mode at the apparatus and helps constituting a flexible system. Furthermore, the present robot control apparatus enables to constitute robot control systems with ease by simply applying a minor modification on the robot control apparatus. The present robot control apparatus contains a robot arm control unit for controlling action of a robot arm and a sequence controller for controlling an apparatus other than the robot arm.  
       [0018] The sequence controller comprises a control section for outputting control signals for controlling action of the apparatus and an input-output section for delivering the signals to the apparatus.  
       [0019] The input-output section comprises a dedicated section and a common processing section for sending signals to the dedicated section. The dedicated section is provided detachable to the common processing section, and outputs signal in accordance with a predetermined output mode.  
       [0020] The above-configured robot control apparatus in the present invention is capable of complying with the input-output modes of respective peripheral devices even in a system formed of various peripheral devices having different input-output modes.  
       [0021] A robot control apparatus in the present invention further comprises a display unit coupled therewith, and the dedicated section is provided with a recognition unit which identifies a predetermined input-output mode. An operator can confirm, through the display unit, a relevant input-output mode of a dedicated section being connected with a certain peripheral device. Whether or not the connection is correct can also be confirmed easily.  
       [0022] A robot control apparatus in the present invention having the above configuration is further provided with an input section in the display unit. The input section includes a selector for selecting a certain dedicated section to be used among a plurality of dedicated sections connected. Thus, a dedicated section compatible with the input-output mode of a peripheral device can be selected through the selector of display unit.  
       [0023] Furthermore, a robot control apparatus in the present invention can be used also for a robot which has a robot main body provided with a robot arm.  
       [0024] Furthermore, a robot containing a robot control apparatus in the present invention can be used on a production facility which contains, for example, machining and welding process steps. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0025]FIG. 1 shows a structure of robot control system in accordance with a first exemplary embodiment of the present invention.  
     [0026]FIG. 2 is a chart used to describe the first embodiment.  
     [0027]FIG. 3 shows a structure of robot control system in accordance with a second exemplary embodiment of the present invention.  
     [0028]FIG. 4 is a chart used to describe the second embodiment.  
     [0029]FIG. 5 shows a structure of robot control system in accordance with a third exemplary embodiment of the present invention.  
     [0030]FIG. 6 shows an example of conventional robot control system. 
    
    
     DESCRIPTION OF THE PREFFERED EMBODIMENTS  
     [0031] (Embodiment 1)  
     [0032] A first exemplary embodiment of the present invention is described below.  
     [0033]FIG. 1 is a block diagram showing a robot control system formed of a robot, a robot control apparatus and peripheral devices of the robot.  
     [0034] Referring to FIG. 1, robot control apparatus  2  comprises robot arm control unit  3  and sequence controller  5 .  
     [0035] Robot arm control unit  3  controls robot main body  1 .  
     [0036] Robot main body  1  includes robot arm  101  and a robot arm driving unit (not shown).  
     [0037] Sequence controller  5  controls peripheral devices  4  working in collaboration with robot main body  1 .  
     [0038] Robot arm control unit  3  and sequence controller  5  exchange signals via bus  20 .  
     [0039] Sequence controller  5  includes input-output section  6  and control section  7 .  
     [0040] Control section  7  transmits and receives signals to and from robot arm control unit  53  via bus  20 .  
     [0041] Input-output section  6  receives a signal representing the operating status from peripheral device  54 , and outputs control signal to peripheral device  4  in accordance with operating status of robot main body  1 .  
     [0042] Control section  7  processes signal from peripheral device  4  and signal from robot arm control unit  3 , and controls input-output section  6  and peripheral device  4 . Control section  7  also reads a program for operating the peripheral devices, and outputs control signal to control operation of peripheral devices.  
     [0043] Control section  7  and input-output section  6  exchange signals via bus  21 .  
     [0044] Input-output section  6  includes dedicated section  8  and common processing section  9 .  
     [0045] Dedicated section  8  handles the input-output of signals in line with the input-output mode of peripheral device  4 .  
     [0046] Common processing section  9  processes information delivered from control section  7  and signal arriving from dedicated section  8 .  
     [0047] Herein, dedicated section  8  is provided detachable to common processing section  9 .  
     [0048] Now the structure of dedicated section  8  and common processing section  9  is described using one exemplary circuit as shown in FIG. 2.  
     [0049] Now a case shown in FIG. 2 will be explained.  
     [0050] In a case of FIG. 2A, an output of general use logic IC  22  is led to the anode of a photo diode in photo coupler  24 , and the cathode is connected to a ground (GND). The collector of photo transistor in photo coupler  24  is connected to a power source, and the emitter is led to the base of transistor  26 . The collector of transistor  26  is treated as the output portion to the outside, while the emitter is connected to the frame GND (FG).  
     [0051] Now a case shown in FIG. 2B will be explained.  
     [0052] In a case of FIG. 2B, output of general use logic IC  32  is led to the anode of a photo diode in photo coupler  34 , and the cathode is connected to the ground (GND), in the same way as in FIG. 2A. The collector of photo transistor in photo coupler  34  is connected to power source, and the emitter is led to the base of transistor  34 . In the case of FIG. 2B, the collector of transistor is connected to power source, and the emitter is treated as output portion to the outside.  
     [0053] In respective cases of the above FIG. 2A and FIG. 2B, a region before the stage of general use logic  22 ,  23 , which region delivering signals to general use logic IC  22 ,  32 , is included in control section  7 . A region starting from general use logic IC  22 ,  32 , ending at photo couplers  24 ,  34  are included in common processing section  9 . A region of transistor  26 ,  36  and thereafter is included in dedicated section  8 .  
     [0054] Therefore, an output mode can be modified by only changing dedicated section  8  (or, transistor  26 ,  36 , in the above-described practical example).  
     [0055] So far in the above, an output channel from dedicated section  8  has been described. An input channel can be formed likewise, with flow of the signal reversed.  
     [0056] The above structure is just exemplary. Instead, the common processing section and the dedicated section may be replaced with different circuit schemes for implementing the same objective.  
     [0057] Thus, by connecting a dedicated section to the common processing section in accordance with the input-output mode of a peripheral device, the coupling between a robot control apparatus and the peripheral devices can be implemented easily with only a minimum operation of modification.  
     [0058] (Embodiment 2)  
     [0059] A second exemplary embodiment of the present invention is described referring to FIG. 3 and FIG. 4. Those portions having the same structure as that of the first embodiment are represented by using the same reference numerals, and the description on which portions are omitted.  
     [0060] Referring to FIG. 3, dedicated section  8  is further provided with recognition unit  10 . Information recognized at recognition unit  10  is delivered to common processing section  9 . The information recognized at recognition unit  10  is delivered also to display unit  11  by way of control section  7 , bus line  20  and robot arm control unit  3 .  
     [0061] Now, the structure of recognition unit  10  is described.  
     [0062] In an exemplary case as shown in FIG. 4, values representing respective input-output modes corresponding to dedicated sections are preset at DIP switch  40 , or the like other means. The preset values are read out to be stored in control section  7  via common processing section  9  and data bus  21 .  
     [0063] Data corresponding to a preset value is sent from robot arm control unit  3  to display unit  11  via data bus  20 . The data delivered from common processing section  9  may either be parallel or serial.  
     [0064] Respective values preset at DIP switch  40  correspond to predetermined input-output modes of dedicated sections  8 . Therefore, control section  7  delivers data of an input-output mode that corresponds to a preset value at DIP switch  40  to display unit  11  to be displayed thereon.  
     [0065] Thus display unit  11  can display an input-output mode of a dedicated section.  
     [0066] A preset value at DIP switch, or at the like means, may further indicate, not only the input-output mode of peripheral device, but a state of peripheral devices connection or types of the peripheral devices, etc.  
     [0067] As described in the above, when a dedicated section is connected with common processing section during an operation of coupling a robot control apparatus with peripheral devices, an operator can confirm on the display unit the input-output mode of the relevant dedicated section being connected to a peripheral device. The display unit also facilitates an easy confirmation that connection of a dedicated section is correct.  
     [0068] (Embodiment 3)  
     [0069] A third exemplary embodiment of the present invention is described with reference to FIG. 5. Those portions having the same structure as that of the first embodiment and the second embodiment are represented by using the same reference numerals, and the description on which portions are omitted.  
     [0070] Referring to FIG. 5, input-output section  6  is provided with a plurality of dedicated sections  8 . The plurality of dedicated sections  8  is connected to a common processing section  9 . Respective dedicated sections  8  in the present embodiment contain recognition unit  10  shown in FIG. 3. Although dedicated section  8  is shown for two units in FIG. 5, it may be provided for a plurality more than two.  
     [0071] Display unit  11  includes input section  12  for used by an operator.  
     [0072] When coupling peripheral device  4  having a specific input-output mode, an operator uses input section  12  to select a suitable dedicated section compatible with the input-output mode of peripheral device  4 . Then, common processing section  9  switches the connection between dedicated sections  8  and control section  7 .  
     [0073] The switching at common processing section  9  can be carried out with ease by making use of a general use logic IC.  
     [0074] That is, control section  7  sends a switching signal to common processing section  9  via bus  21 , in response to a signal delivered from input section  12  telling to select dedicated section  8 . In common processing section  9 , a connection between a dedicated section, which inputs/outputs signals of control section  7  for controlling peripheral device  4 , and control section  7  is switched by means of a selector which is one of general use logic ICs.  
     [0075] Through a procedure as described above, dedicated section  8  that fits to specific input-output mode of peripheral device  4  is selected from among a plurality of dedicated sections  8  connected with common processing section  5 , in accordance with instruction delivered from input section  12  of display unit  11 .  
     [0076] Each of the plurality of dedicated sections may be provided with a symbol and the like for recognizing which section is used, so that input section  12  of display unit  11  can select a suitable dedicated section.  
     [0077] Description in the above exemplary embodiments has been based mainly on a robot control apparatus. Robot control apparatus described in the above embodiments can be used for a robot including the robot main body having a robot arm.  
     [0078] Furthermore, a robot containing a robot control apparatus in the above-described embodiment can be used in a production facility which includes a machining process, an welding and the like process steps.  
     INDUSTRIAL APPLICABILITY  
     [0079] A robot control apparatus in the present invention can comply with different input-output modes of peripheral devices with less adapting operation. And modifying operation can be implemented easily.  
     [0080] Furthermore, in a robot control apparatus in the present invention, a display unit facilitates an easy recognition of input-output modes, connection status, as well as kinds and relevant information regarding the peripheral devices.  
     [0081] Still further, when coupling a robot control apparatus in the present invention with peripheral devices, an operator can select a suitable dedicated section that fits to the input-output mode of a peripheral device through an input section of display unit. Thus the coupling as well as the change in the coupling with peripheral devices can be implemented easily in a flexible manner.