1. Degrees of freedom
The number of joints that the robot mechanism can independently move is called the degree of freedom of the robot mechanism, which is abbreviated as DOF. At present, the control method adopted by industrial robots is to treat each joint on the mechanical arm as a separate servo mechanism, that is, each axis corresponds to a server, and each server is controlled by the bus, which is controlled and coordinated by the controller.
In the current industrial applications, three axis, four axis, five axis double arm and six axis industrial robots are mostly used. The selection of the number of axes usually depends on the specific application; In the industrial field, the six axis robot is the most widely used.
2. Joint
That is, motion pair, a mechanism that allows relative motion between parts of the robot arm. The precision reducer is the core component of its movement. It uses the speed converter of the gear to reduce the number of rotations of the motor to the desired number of rotations and obtain a device with larger torque, thereby reducing the speed and increasing the torque.
3. Scope of work
The working range of an industrial robot refers to the space area that the robot arm or hand mounting point can reach. Because the size and shape of the hand end effector are various, in order to truly reflect the characteristic parameters of the robot, this refers to the working area when the end effector is not installed.
The shape and size of the robot's working range are very important. When a robot performs a task, it may be unable to complete the task because of the dead zone that cannot be reached by the hand.
The number of degrees of freedom the robot has and the combination of machines determine its motion pattern; The variation of the degree of freedom (that is, the distance of linear motion and the size of the rotation angle) determines the size of the motion pattern.
The working range of the robot is generally expressed by two methods: graphical method and analytical method.
4. Speed
The distance or rotation angle of the center of the mechanical interface or the center of the tool in unit time when the robot is working with load and moving at a constant speed.
At present, the small load industrial robot can achieve 1.0m/s-1.5m/s, and the small robots launched by ABB, KUKA, FANUC, etc. can basically reach 5-6m/s.
5. Workload
It refers to the maximum weight that the load installed at the front end of the robot wrist can bear at any position within the working range, generally expressed in terms of mass, torque and moment of inertia. It is also related to running speed, acceleration and other parameters. Generally, the workload is determined by the weight of the work piece that the robot can grasp at high speed. The total weight of the gripper and the work piece must be considered for the load weight of the handling robot.
6. Resolution
It refers to the minimum moving distance or minimum rotation angle that the robot can achieve, which is divided into programming resolution and control resolution.
7. Precision
Positioning accuracy: refers to the difference between robots reaching a target position repeatedly. The accuracy of industrial robots is characterized by repetitive positioning accuracy and absolute positioning accuracy. The absolute positioning accuracy indicates the deviation between the teaching value and the actual value; Repetitive positioning accuracy refers to the position deviation of a robot that repeatedly reaches a point.