Patent Application
20230373099
This disclosure relates generally to a system and method for transmitting signals between a teaching tablet and a controller for teaching a robot and, more particularly, to a system and method for wirelessly transmitting signals between a teaching tablet and a controller for teaching a painting robot.
Robots are known to perform a multitude of tasks including painting an object, such as a vehicle body. A typical painting station for painting, for example, the exterior surfaces of vehicle bodies in both a continuous conveyance and stop station systems includes a spray booth, a plurality of painting robots and opener/closer robots disposed on a periphery thereof. These robots can be mounted on the floor, the wall, the ceiling or side rails. The painting robots carry either spray guns or rotary applicators for directing atomized paint toward the vehicle body.
Augmented reality (AR) has been described as an interactive experience of a real-world environment where objects that reside in the real-world are enhanced by computer-generated perceptual information in the virtual world. The use of AR systems for simulating the operation of industrial robots for calibration purposes, teaching purposes, etc. is known in the art. An AR system can be used, for example, for teaching a robot how to perform a certain operation, such as painting a vehicle, welding vehicle body panels, etc., where a skilled operator uses the AR system to demonstrate the operation and the robot learns the motions involved in a manner well understood by those skilled in the art. The AR system can also be used for other teaching activities, such as establishment of virtual safety zones into which the robot must not encroach.
In one known design, an AR program or other robot teaching program is loaded onto a handheld teaching pendant tablet and the tablet is mounted in a tablet cradle having an enable switch that must be held while the robot is being taught and is moving and an emergency stop push button, which both operate as safety features. Generally, a standard teaching pendant cable connects the cradle, which is inside of the safety fence of the robot, to the robot controller, which is outside of the safety fence, where the data signals operate using the Ethernet to provide the desired data speed. The tablet cradle includes a circuit board that converts an Ethernet (TCP/IP) communications signal from the cable to a USB-C type connection for the tablet. This hardwired USB-C connection provides the data connection to the tablet that displays the robot status and provides teaching, jogging, programming and configuration setting controls of the robot.
The paint that is sprayed by a painting robot is combustible and therefore various precautions need to be taken so that the electrical signals on the cables between the tablet and the robot controller and the electrical signals on the connections between the tablet and the cradle cannot generate sparks that could ignite the paint in the atmosphere. The safety signals traveling from the enable switch and emergency stop button on the cradle to the robot controller can be provided on a safety signal cable, which prevents any possibility of generating a spark. However, the data signals that are high speed, constantly on and complex and travel over the Ethernet connection cannot use such safety cables, and thus it is very difficult, bulky and expensive to provide the level of safety required for these data signals. Further, certain ones of the known teach pendant tablets are only authorized for the painting robot environment if nothing else is plugged into it, and thus being connected to the cradle violates that protocol.
The following discussion discloses and describes a system and method for teaching a painting robot using wireless signals. The system includes a robot teaching assembly having a teaching tablet and a cradle to which the tablet is mounted, where the tablet includes a screen and a tablet Wi-Fi radio. The system also includes a robot controller assembly having a robot controller and a controller Wi-Fi radio, where the tablet radio and the controller radio are in wireless communication with each other to transmit signals to teach the robot. The cradle includes an emergency stop button for stopping the robot and an enable switch that must be closed to allow the robot to operate. The emergency stop button and enable switch are electrically coupled to the robot controller assembly by a safety signal cable. The cradle and the teaching tablet are not electrically coupled.
Additional features of the disclosure will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.
The following discussion of the embodiments of the disclosure directed to a system and method for wirelessly transmitting signals between a teaching tablet and a controller for teaching a painting robot is merely exemplary in nature, and is in no way intended to limit the disclosure or its applications or uses.
The tablet 28 has a built in radio 60 for wireless communications purposes over a Wi-Fi protocol. The system 38 also includes a radio 62 shown here mounted to or in the ACP 32, although the radio 62 can be separated from the ACP 32 and be wirelessly connected to it using a suitable antenna. The radio 62 is powered by a power unit 64 in the ACP 32 and is in electrical communication with the controller 58 on line 66. Therefore, the Ethernet communications signals are wirelessly transmitted between the tablet 28 and the controller 58 for teaching the robot 12, which removes the electrical connection that could otherwise generate a spark, and the safety signals are reliably hardwired between the tablet 28 and the controller 58.
This system 38 also accommodates the application for when using the tablet 28 to “echo” the screen of another teaching pendant device. Specifically, the same method of connecting a tablet computing device to a paint robot controller by Wi-Fi connection for data communications can also be used to “echo” the screen of another teaching pendant device. The “echo” function can be used to display whatever is being transmitted to one teaching pendant device to a second device using Wi-Fi. In the case of the “echo” mode the tablet 28 does not provide any control functions and only displays the same HMI screen output as the one teaching pendant device.
The foregoing discussion discloses and describes merely exemplary embodiments of the present disclosure. One skilled in the art will readily recognize from such discussion and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the spirit and scope of the disclosure as defined in the following claims.
