The steps to realize the action of grabbing cans by using the four-bar mechanism are as follows:

1. Design a four-bar mechanism to adapt to the shape and size of cans.

2. Choose a suitable driver, such as motor or pneumatic motor, to drive the four-bar mechanism to move.

3. Design the action of four-bar mechanism, so that it can clamp and lift cans.

4. Motion control is realized by the sensor and the control unit to ensure that the motion speed, trajectory and grasping strength of the four-bar mechanism are appropriate.

5. Test and adjust to ensure that the four-bar mechanism can correctly grasp the jar.