How to realize the flexibility of industrial robots?

The robot tool changer makes the application of robots more flexible by automatically changing different end effectors or peripheral devices. These end effectors and peripherals include, for example, spot welding guns, grippers, vacuum tools, pneumatic and electric motors, etc. The tool quick change device includes a robot side for mounting on the robot arm and a tool side for mounting on the end effector. The tool quick change device can connect different media such as gas, electric signal, liquid, video, ultrasound, etc. from the robot arm to the end effector. The advantages of the robot tool quick change device are:

1. The replacement of the production line can be completed within a few seconds;

2. Maintenance and repair tools can be replaced quickly, greatly reducing downtime;

3. Increase flexibility by using more than one end effector in the application;

4. Replace the original heavy and complex multi-functional tooling actuator with the end effector that automatically exchanges single functions.

The robot tool quick change device enables a single robot to exchange and use different end effectors in the manufacturing and equipment process to increase flexibility. It is widely used in automatic spot welding, arc welding, material grasping, stamping, testing, crimping, assembly, material removal, burr cleaning, packaging and other operations. In addition, the tool quick change device can provide backup tools for tools in some important applications to effectively avoid accidents. It takes several hours to replace tools, and the automatic replacement of standby tools by the tool quick change device can be completed in a few seconds. At the same time, the device is also widely used in some non robot fields, including pallet system, flexible fixture, manual spot welding and manual material lifting.

Vision guidance and positioning of industrial robots

For the industrial robots working on the automatic production line, the most completed type of operation is the “grab place” action. In order to complete this kind of operation, it is necessary to obtain the positioning information of the operated object. First, the robot must know the position and posture of the object before being operated to ensure that the robot can grasp it accurately; Secondly, it is necessary to know the position and posture of the target after the object is operated to ensure that the robot can complete the task accurately.

In most industrial robot applications, the robot only operates according to a fixed procedure. The initial position and end position of the object are specified in advance. The quality of the task is guaranteed by the positioning accuracy of the production line. For high-quality operation, the production line is required to be relatively fixed and the positioning accuracy is high. As a result, the production flexibility is reduced, but the cost is greatly increased. At this time, the flexibility of the production line and the product quality are contradictory.

Visual guidance and positioning is an ideal tool to solve the above contradiction.

The industrial robot can understand the changes of the working environment in real time through the vision system, adjust the action accordingly, and ensure the correct completion of the task. In this case, even if there is a large error in the adjustment or positioning of the production line, it will not have much impact on the accurate operation of the robot. The vision system actually provides an external closed-loop control mechanism to ensure that the robot automatically compensates for the error caused by environmental changes.

The ideal visual guidance and positioning should be based on visual servo. First, observe the approximate orientation of the object, then observe the deviation between the manipulator and the object while the manipulator is moving, and adjust the movement direction of the manipulator according to the deviation until the manipulator and the object are in accurate contact. However, there are many difficulties in the implementation of this positioning method.

Direct vision guidance and positioning is to describe the spatial position and posture of objects in the robot environment in detail once and guide the robot to complete the action directly. Compared with the method based on visual servo, the calculation amount of direct visual guidance is greatly reduced, which creates conditions for practical application. However, this must be based on a premise: the vision system can accurately determine the three-dimensional position and posture information of the object in the robot space (in the base coordinate system).