SE1200076A1 - En metod för att automatiskt koppla bort ett trådlöst hålldon till en industri robot - Google Patents

Abstract

Föreliggande uppfinning avser en metod för att automatiskt koppla bort ett trådlöst hålldon till en industrirobot, som är anslutet till robotens säkerhetssystem. Metoden innefattar övervakning av huruvida hålldonet inte har använts under en viss tidsperiod, och om så är fallet utförs följande steg: en begäran skickas till hålldonet om att denna ska bekräfta att hålldonet ska fortsätta. att vara ansluten till säkerhetssystemet, och. hålldonet kopplas bort från säkerhetsystemet om säkerhetssystemet inte får tillbaka någon bekräftelse from hålldonet, och anslutningen kvarstår om säkerhetssystemet får tillbaka en bekräftelse from hålldonet.Detta innebär att operatören måste periodvis aktivera robotens "enabling" funktion för att bibehålla anslutingen till robotens säkerhetsfunktion.(Fig. 1)

Description

safety regulation for the robot specifies that the enabling device must be connected to the safety system of the robot when the enabling device is inside the robot cell. To avoid accidents enabling button should be out of function as long as the enabling device is outside the robot cell.

Sometimes it is necessary to be more than one person in the cell at the same time. Each person in the robot cell must have an enabling device that is connected to the safety system.

To be able to move the robot, all enabling buttons of the enabling devices which are connected to the safety system must be pressed at the same time. If one of the enabling buttons is not pressed, the safety system does not allow the robot to move.

Problem It is known to have wireless enabling devices. When working in a robot cell with one or more Wireless enabling devices, it is possible that an operator having a wireless enabling device leaves the robot cell, and forgets to disconnect the enabling device from the safety system. In that case, it is not possible for the other operators to move the robot.

Brief description of the invention The object of the present invention is to provide a solution to this problem.

This object is achieved by a method comprising supervising whether or not the enabling device in use, and performing the following steps upon detecting that the enabling device has not been in use for a certain time intervall sending a request to the enabling device to acknowledge that the enabling device shall continue to be connected to the safety system, and disconnecting the enabling device if no acknowledge is received from the enabling device, and continuing the connection of the enabling device if an acknowledge is received from the enabling device.

Thus, in order to stay connected to the safety function, the operator needs to periodically activate the enabling function of the robot.

The invention also makes the robot cell safer because the enabling device will be automatically disconnected from the safety system if the enabling device is not used for a while and the operator does not confirm that the enabling device shall continue to be connected to the safety system.

Detailed description of the invention Figure 1 shows an example of a robot system including an industrial robot 1 located within a robot cell surrounded by a safety arrangement, for example, a fence 2. A robot cell is a defined safe area surrounding the manipulator. Within the robot cell certain safety rules are applied. One safety rule is that the enabling device must be connected to the safety system When the enabling device is within the robot cell. The robot system further includes a safety unit 3, for example a PLC, including the safety system of the robot. The robot system further includes a plurality of portable enabling devices 4a'c. The enabling devices 4a-c are wireless and communicate with the safety unit 3 via a wireless data link. Each enabling device includes an antenna for wireless communication with the safety unit 3 and the robot control unit. The safety system may be integrated in a robot control unit 6 as shown in the figure.

The enabling device 4a-c comprises a button 5 that has to be pressed down by the operator to enable manual control of the movements of the robot, for example, by means of a joystick.

When the operator releases the button of the enabling device, the robot can no longer be manually moved. In figure 1, there are three enabling device 4a-c connected to the safety unit 3. Two of the enabling device 4a-b are located inside the robot cell and one enabling device 4c is located outside the cell. To be able to move the robot the enabling buttons 5 on all three enabling device have to be pressed at the same time. If one of the buttons is not pressed, it is not possible to move the robot.

When working in the robot cell, a wireless enabling devices has to be connected or to be activated to gets its enabling function. According to the invention, this activation will only be valid for a certain time period to avoid activated enabling devices When no user requires the function. The enabling function times out, i.e. is automatically disconnected after a certain time interval if it has not been used. To prevent disconnection of the enabling function, the user must take some sort of action, such as, press the enabling button or another button on the enabling device.

The safety unit 3 in provided with means for supervising the enabling devices 4a-c and to detect if any of the enabling devices has not been in use for a certain time interval, for example 10 minutes. With not in use is meant that the enabling button has not been used.

Upon detecting that the enabling button has not been used for during a predetermined time interval, the safety unit sends a request to the enabling device to acknowledge that the enabling device shall continue to be connected to the safety system, and if no acknowledge is received from the enabling device the safety unit will disconnect the enabling device.

Otherwise, if acknowledge is received from the enabling device, the enabling device will continue to be connection to the safety unit.

To call for the attention of the user When the enabling device receives the request to acknowledge that the enabling device shall continue to be connected to the safety system, some type of visible or audible signal should be generated upon receiving the request. For example, each enabling devices can be provided with a lamp or LED 7, Which starts to flash upon receiving the request. When the user presses the enabling button, a reply is sent to the safety unit and the lamp is turned off.

Claims (1)

Claim

1. A method for automatically disconnecting a wireless enabling device of an industrial robot, Which enabling device is connected to a safety system of the robot, characterized in that the method comprisesï - supervising whether or not the enabling device in use, performing the following steps upon detecting that the enabling device has not been in use for a certain time periodï o sending a request to the enabling device to acknowledge that the enabling device shall continue to be connected to the safety system, and o disconnecting the enabling device if no acknowledge is received from the enabling device, and o continuing the connection of the enabling device if an acknowledge is received from the enabling device.