Data processing: generic control systems or specific application – Specific application – apparatus or process – Robot control
Reexamination Certificate
2000-11-28
2002-06-04
Louis-Jacques, Jacques H. (Department: 3661)
Data processing: generic control systems or specific application
Specific application, apparatus or process
Robot control
C700S056000, C700S083000, C700S086000, C700S245000, C700S292000, C029S430000, C029S783000, C029S787000, C901S006000, C901S008000, C318S587000, C414S277000
Reexamination Certificate
active
06401011
ABSTRACT:
BACKGROUND TO THE INVENTION
1. Field of the Invention
The present invention relates to a work-transporting robot provided between a plurality of press machines; particularly, the present invention relates to a synchronous control device for a plurality of robots.
2. Description of the Related Art
Conventionally known are press systems where pressing by a plurality of press machines occurs by transporting a work item in sequence using a work transport line. The work transport line involves a plurality of robots, a material supply device at an upstream side, a product removal device at a downstream side, and a plurality of intermediate stages.
Each robot transports a work item in a sequential manner between the intermediate stages. Each robot, the material supply device, and the product removal device are conventionally operated in an electronically linked manner, as will be described. During operation, each of the robots travels to a work retrieve position, from a home position, retrieves the work item, advances to a work release position, releases the work item, and returns to the home position.
During conventional operation, the position of the robots is matched at both a midpoint in the advance motion and the return motion. The midpoints are also linked to the motion of the material supply device and the product removal device, as will be explained. When each of the robots reaches the return midpoint, the corresponding press machines are activated and pressing is conducted.
During the advance and the return motion, a transporting speed for each of the robots may differ as a result in several factors. These factors include, differences in the weight of each work item, differences in the advance and return motions, and differences in retrieve and release motions. Thus, during adjustment to the press machines, robots, work transport line, or product removal device, each of the robots must be operated alone in order to avoid interference with adjacent robots or other devices.
Referring now to
FIG. 6
, a conventional flow control diagram for the work transport line includes a master board
17
linking a programmable controller
18
to three robots
3
a
′,
3
b
′, and
3
c
′. Additional conventional links to the material supply device (not shown) and the material removal device (not shown) are omitted for clarity.
Each robot
3
a
′,
3
b
′, and
3
c
′ includes a programmable controller
16
, a servo amp
15
and a servo motor
14
each in electronic communication with the other. Each robot
3
a
′,
3
b
′, and
3
c
′ is linked to and controlled by programmable controller
18
, through corresponding programmable controller
16
. Electronic communications pass from programmable controller
16
, by corresponding servo amp
15
, to servo motor
14
. Each servo motor
14
acts as a drive source for each corresponding robot
3
a
′,
3
b
′, and
3
c
′ through a mechanical construction member (not shown).
During conventional linked operation, programmable controller
18
signals each robot
3
a
′,
3
b
′, and
3
c
′, through corresponding programmable controllers
16
, to go to the corresponding work retrieve positions, retrieve the work items, and advance to the advance midpoints and wait. Once programmable controllers
18
,
16
confirm that all robots
3
a
′,
3
b
′, and
3
c
′ have reached the advance midpoints, each robot
3
a
′,
3
b
′, and
3
c
′ advances to the corresponding work release position and releases the work items.
After releasing the work items, robots
3
a
′,
3
b
′, and
3
c
′ return to the corresponding return midpoints and wait. Once programmable controllers
18
,
16
confirm that all robots
3
a
′,
3
b
′, and
3
c
′ have reached the corresponding return midpoints, all robots
3
a
′,
3
b
′, and
3
c
′ wait for further signals from programmable controller
18
. The return midpoint is also a home position for robots
3
a
′,
3
b
′, and
3
c
′. When robots
3
a
′,
3
b
′, and
3
c
′ have reached the corresponding return midpoints, the corresponding press machines are activated. Repetition of the above described conventional process advances corresponding work items through the press system (not shown).
Using the conventional process, only the midpoint in the advance and the midpoint in the return are matched for corresponding robot
3
a
′,
3
b
′, and
3
c
′. As a result, the general movements of robots
3
a
′,
3
b
′, and
3
c
′ are not continuously synchronized.
During adjustment, exchange of dies, or other maintenance activity conducted on the press system (not shown), robots
3
a
′,
3
b
′, and
3
c
′ are operated individually in an inching operation (not shown). Since adjacent robots
3
a
′,
3
b
′, and
3
c
′ are not synchronized, the inching operation is conducted by individual inching movements (not shown). In this case, to avoid interference between adjacent robots
3
a
′,
3
b
′, and
3
c
′, the range of inching movement is limited. As a result, adjustment, exchange of dies, or other maintenance activity is complex and time consuming thereby increasing operating costs.
OBJECT AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a synchronous control device for a robot.
It is another object of the present invention to provide a synchronous control device to synchronize the operation of multiple work-transporting robots without matching the position of the robots at a point.
It is another object of the present invention to provide a synchronous control device adaptable to synchronize an inching or linked operation of multiple robots.
It is another object of the present invention to provide a synchronous control device for multiple robots that minimizes the danger of interference between adjacent robots during inching or linked operation.
A synchronous control device receives expansion data describing robot movement, stores the expansion data in a storage element, and in accordance with an internal clock or encoder equivalent, outputs the expansion data to a positioning controller through an output element to continuously control robot movement.
According to an embodiment of the present invention there is provided a synchronous control device comprising: an internal clock being of a type equivalent to a speed of an outside element, means for storing data characterizing a path and the speed of the outside element, means for outputting the data to a positioning controller in accordance with the internal clock, and the positioning controller receiving the data and controlling the outside element, whereby the outside element is continuously synchronized with the data.
According to another embodiment of the present invention there is provided a synchronous control device, comprising: means for storing data characterizing a path of a robot, a clock being of a type equivalent to a speed of said robot, means for outputting the data to a positioning controller in accordance with the clock, and the positioning controller commanding a control source for the robot, whereby the robot is continuously synchronized with the data.
According to another embodiment of the present invention there is provided a synchronous control device wherein: the clock is replaced with an encoder signal detecting a crank position of the robot.
According to another embodiment of the present invention there is provided a synchronous control device for a robot, being a synchronous control device for a work-transporting robot provided between press machines and having a drive source, comprising: an internal clock being of a type equivalent to a motion speed of the robot, a positioning controller being of a type which outputs a command signal to a drive source for the robot, means for storage being of a type which stores data describing a path of the robot, and means fo
Aida Engineering Co., Ltd.
Louis-Jacques Jacques H.
Marc McDieunel
Morrison Law Firm
LandOfFree
Synchronous control device for robots does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Synchronous control device for robots, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Synchronous control device for robots will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2979318