Summary of three servo machines and their installed sensors

It is predicted that collaborative robots will grow tenfold from 2015 to 2020, and the market value will rise from $95 million in 2014 to $1 billion, while lightweight robots will be popular in two years and prices will drop to 1.5 to 20,000. Dollar. Analytical company TechNavio predicts that by 2019, the annual compound growth rate of global collaborative robots will be 50.88%.

1. Three major representatives - Japanese, European and domestic

Yaskawa: Human-Machine Cooperative Robot MOTOMAN-HC10

There are two common problems in the market for man-machine cooperation security settings: First, it is necessary to set up safety gratings to protect personal safety, increase equipment and cost investment; second, the operation is complicated, and the unskilled operators cannot control the robot. .

To this end, Yaskawa Electric has introduced the MOTOMAN-HC10 with the characteristics of “use immediately after setting” and “safe and convenient”. All axes are equipped with a force sensor that automatically stops working when it is touched by the human body. The outer arm of the machine is wrapped with a blue soft material for absorbing collisions. It can completely work in the same space as the HC10. It does not require a safety barrier and saves costs.

Youao: the world's first, UR5 robot

Referring to the representative of the European Department, the U-Robot is doing its part. The UR5 is arguably the world's first collaborative robot, which was launched in 2009. Human commands can be understood only through sounds, gestures, and graphics; human-machine collaboration can be safely produced without obstructions, with superior human perception performance; modular plugs and production components, an integrated robotic system that can be deployed in three days.

Shinsong: "Tai Chi" 7-joint robot

What is the flexibility of industrial robots? As we all know, the most important factor is the number of axes. The number of robot axes determines the degree of freedom. The higher the degree of freedom, the closer the robot is to the man's action function, and the better the versatility; but the more degrees of freedom, the more complex the structure, the higher the overall requirements for the robot. A contradiction in robot design.

This 7-axis flexible multi-joint robot can be said to be the first 7-degree-of-freedom cooperative robot in China, with functions such as quick configuration, traction teaching, visual guidance, and collision detection. If you work in a small space and you need to repeatedly twist and reverse the arm, this seven-axis robot is a good choice.

2, the ultimate ambiguity - product definition of collaborative robots

flexibility

Compared to industrial robots on traditional large-scale production lines, collaborative robots need to work with humans. The size of the structure should be lighter, more flexible, and more steerable.

Ease of use

Collaborative robots emphasize ease of use, such as gestures, followed by sensible devices, lowering the threshold for use, and front-line workers may only need to operate for hours, eliminating the complex programming and configuration of traditional industrial robots.

safety

Collaborative robots are mainly used for human-computer collaboration, working with humans, must be safe, and cannot be harmed to humans by accident. This requires high sensitivity and control of the collaborative robot.

low cost

Collaborative robots are aimed at small and medium-sized enterprises. The lowest possible cost is very important, but often the low cost performance will also be reduced. It is relatively difficult to control the cost while improving performance.

3, indispensable - servo and sensor

To have the above four characteristics, a cooperative robot must have the ability to sense, control, and limit torque. By perceiving externally small torque changes and reacting to avoid collisions, the collaborative process is easier and safer.

(1) Ultra-small, powerful servo drive

A drive is physically small enough to fit directly on the robot joint, ensuring that the robot is compact and compact. The servo drive is directly mounted on the robot joint, and the driver can be placed close enough to the encoder feedback to save the cable , reduce the interference effect, obtain relatively low EMI and RFI indicators, and greatly improve the system stability. Another feature that makes the drive easier to integrate into the joint is the inherent robustness of the drive, which can withstand the extremely high mechanical acceleration and deceleration in the joint.

(2) Double closed loop control algorithm

The double closed loop control algorithm can improve the performance of the servo motor to an optimal state. Each axis in the system uses a double closed loop control algorithm to improve the positioning accuracy of the end position of the rear end of the reducer. The incremental encoder and Hall element are placed in front of the gearbox as speed loop feedback, and a 19-bit high resolution absolute encoder is used as load end position feedback.

(3) Motion redundancy

Kinematic redundancy is useful for manipulating several robots in a particular space because motion interference is easy to handle. Six degrees of freedom are the minimum number of degrees of freedom to complete spatial positioning, and more than six axes of robots, collectively referred to as redundant degrees of freedom robots. Compared to the traditional 6-joint robot, the 7-joint robot can extend the arm to a specific original with multiple angles. Redundant degrees of freedom robots have more advantages in obstacle avoidance, overcoming singularities, flexibility and fault tolerance, so industrial robots with redundant degrees of freedom will have more use in complex work environments.

(4) Torque sensor

In a human-machine collaborative environment, these robots are arranged to perform high-speed, high-precision tasks. Using cameras, force sensors, and other sensing components, the robot can sense the presence of people and act accordingly to avoid harm to people. In some cases, the torque sensor is placed behind the motor gearbox to directly detect any rapid increase in external torque; at other times, the robot needs to output a certain amount of torque to lift the load and move the load from one position to another. . When the robot recognizes an abnormal torque increase value during the movement, such as a collision, it will automatically stop.

(5) Safety sensor

In order for industrial robots to collaborate with people, first find a way to ensure the safety of workers. These sensors come in a variety of forms, from camera to laser, for one purpose, to tell the situation around the robot. The simplest example is the laser safety sensor on the elevator door. When the laser detects an obstacle, the door immediately stops closing and retracts to avoid a collision. This is almost the case with most safety sensors in the robotics industry.

(6) Parts detection sensor

In the part picking application, (assuming there is no vision system), you can't know if the robot gripper grabbed the part correctly. The part inspection application gives you feedback on the position of the gripper. For example, if the gripper misses a part, the system detects the error and repeats the operation once to ensure that the part is properly captured.