The robotic arm is the most common type of robot in modern industrial robots. It can imitate certain movements and functions of human hands and arms, and can grasp, carry objects or operate specific tools through fixed programs. It is the most widely used automation device in the field of robotics. Its forms are different, but they all have a common feature, which is that they can accept instructions and accurately locate to any point in three-dimensional (two-dimensional) space to perform operations. Its characteristics are that it can complete various expected operations through programming, and its structure and performance combine the advantages of both humans and mechanical machines. It can replace human heavy labor to realize the mechanization and automation of production, and can operate in harmful environments to protect personal safety. Therefore, it is widely used in machinery manufacturing, electronics, light industry and atomic energy.
1.Common robotic arms are mainly composed of three parts: the main body, the drive mechanism and the control system
(I) Mechanical structure
1. The fuselage of the robotic arm is the basic support part of the entire device, usually made of sturdy and durable metal materials. It must not only be able to withstand the various forces and torques generated by the robotic arm during work, but also provide a stable installation position for other components. Its design needs to take into account balance, stability and adaptability to the working environment. 2. Arm The arm of the robot is the key part to achieve various actions. It consists of a series of connecting rods and joints. Through the rotation of the joints and the movement of the connecting rods, the arm can achieve multi-degree-of-freedom movement in space. The joints are usually driven by high-precision motors, reducers or hydraulic drive devices to ensure the movement accuracy and speed of the arm. At the same time, the material of the arm needs to have the characteristics of high strength and light weight to meet the needs of fast movement and carrying heavy objects. 3. End effector This is the part of the robot arm that directly contacts the work object, and its function is similar to that of a human hand. There are many types of end effectors, and the common ones are grippers, suction cups, spray guns, etc. The gripper can be customized according to the shape and size of the object and is used to grab objects of various shapes; the suction cup uses the negative pressure principle to absorb the object and is suitable for objects with flat surfaces; the spray gun can be used for spraying, welding and other operations.
(II) Drive system
1. Motor drive The motor is one of the most commonly used drive methods in the robot arm. DC motors, AC motors and stepper motors can all be used to drive the joint movement of the robot arm. Motor drive has the advantages of high control accuracy, fast response speed and wide speed regulation range. By controlling the speed and direction of the motor, the motion trajectory of the robot arm can be accurately controlled. At the same time, the motor can also be used in conjunction with various reducers to increase the output torque to meet the needs of the robot arm when carrying heavy objects. 2. Hydraulic drive Hydraulic drive is widely used in some robot arms that require large power output. The hydraulic system pressurizes the hydraulic oil through a hydraulic pump to drive the hydraulic cylinder or hydraulic motor to work, thereby realizing the movement of the robot arm. Hydraulic drive has the advantages of high power, fast response speed, and high reliability. It is suitable for some heavy robot arms and occasions that require fast action. However, the hydraulic system also has the disadvantages of leakage, high maintenance cost, and high requirements for the working environment. 3. Pneumatic drive Pneumatic drive uses compressed air as a power source to drive cylinders and other actuators to work. Pneumatic drive has the advantages of simple structure, low cost, and high speed. It is suitable for some occasions where power and precision are not required. However, the power of the pneumatic system is relatively small, the control accuracy is also low, and it needs to be equipped with a compressed air source and related pneumatic components.
(III) Control system
1. Controller The controller is the brain of the robot arm, responsible for receiving various instructions and controlling the actions of the drive system and mechanical structure according to the instructions. The controller usually uses a microprocessor, a programmable logic controller (PLC) or a dedicated motion control chip. It can achieve precise control of the position, speed, acceleration and other parameters of the robot arm, and can also process the information fed back by various sensors to achieve closed-loop control. The controller can be programmed in a variety of ways, including graphical programming, text programming, etc., so that users can program and debug according to different needs. 2. Sensors The sensor is an important part of the robot arm’s perception of the external environment and its own state. The position sensor can monitor the position of each joint of the robot arm in real time to ensure the movement accuracy of the robot arm; the force sensor can detect the force of the robot arm when grasping the object to prevent the object from slipping or being damaged; the visual sensor can recognize and locate the working object and improve the intelligence level of the robot arm. In addition, there are temperature sensors, pressure sensors, etc., which are used to monitor the working status and environmental parameters of the robot arm.
2.The classification of the robot arm is generally classified according to the structural form, driving mode, and application field
(I) Classification by structural form
1. Cartesian coordinate robot arm The arm of this robot arm moves along the three coordinate axes of the rectangular coordinate system, namely the X, Y, and Z axes. It has the advantages of simple structure, convenient control, high positioning accuracy, etc., and is suitable for some simple handling, assembly and processing tasks. However, the working space of the rectangular coordinate robot arm is relatively small and the flexibility is poor.
2. Cylindrical coordinate robot arm The arm of the cylindrical coordinate robot arm consists of a rotary joint and two linear joints, and its motion space is cylindrical. It has the advantages of compact structure, large working range, flexible movement, etc., and is suitable for some medium-complexity tasks. However, the positioning accuracy of the cylindrical coordinate robot arm is relatively low, and the control difficulty is relatively high.
3. Spherical coordinate robot arm The arm of the spherical coordinate robot arm consists of two rotary joints and one linear joint, and its motion space is spherical. It has the advantages of flexible movement, large working range, and ability to adapt to complex working environments. It is suitable for some tasks that require high precision and high flexibility. However, the structure of the spherical coordinate robot arm is complex, the control difficulty is large, and the cost is also high.
4. Articulated robot arm The articulated robot arm imitates the structure of the human arm, consists of multiple rotary joints, and can achieve various movements similar to the human arm. It has the advantages of flexible movement, large working range, and ability to adapt to complex working environments. It is currently the most widely used type of robotic arm.
However, the control of articulated robotic arms is difficult and requires high programming and debugging technology.
(II) Classification by drive mode
1. Electric robotic arms Electric robotic arms use motors as drive devices, which have the advantages of high control accuracy, fast response speed, and low noise. It is suitable for some occasions with high requirements for accuracy and speed, such as electronic manufacturing, medical equipment and other industries. 2. Hydraulic robotic arms Hydraulic robotic arms use hydraulic drive devices, which have the advantages of high power, high reliability, and strong adaptability. It is suitable for some heavy robotic arms and occasions that require large power output, such as construction, mining and other industries. 3. Pneumatic robotic arms Pneumatic robotic arms use pneumatic drive devices, which have the advantages of simple structure, low cost, and high speed. It is suitable for some occasions that do not require high power and accuracy, such as packaging, printing and other industries.
(III) Classification by application field
1. Industrial robotic arms Industrial robotic arms are mainly used in industrial production fields, such as automobile manufacturing, electronic product manufacturing, and mechanical processing. It can realize automated production, improve production efficiency and product quality. 2. Service robotic arm Service robotic arm is mainly used in service industries, such as medical, catering, home services, etc. It can provide people with various services, such as nursing, meal delivery, cleaning, etc. 3. Special robotic arm Special robotic arm is mainly used in some special fields, such as aerospace, military, deep-sea exploration, etc. It needs to have special performance and functions to adapt to complex working environments and task requirements.
The changes that robotic arms bring to industrial manufacturing production are not only the automation and efficiency of operations, but also the accompanying modern management model has greatly changed the production methods and market competitiveness of enterprises. The application of robotic arms is a good opportunity for enterprises to adjust their industrial structure and upgrade and transform.
Post time: Sep-24-2024
