Is flexible robot the development trend of collaborative robot?

2020-06-18 17:24:49
Co-robots refer to robots designed to interact directly with people in collaboration areas. Small and media-sized enterprises (SMEs) are an important client group of co-robots, and the rise of co-robots is closely related to SMEs.

The origins of co-robots

Esben "Ostergaard, Kasper Stoy and Kristian Mr Kassow starts his when doing research at the university of southern Denmark established Universal Robot, and now the CEO of Esben stergaard was an assistant professor at the university of southern Denmark, three people found the small and medium-sized enterprise the new demand for the Robot (also with the Danish government dominated a Robot program), and in 2009 launched the first collaboration UR5 Robot. Most co-robots before UR5 are modified on the basis of traditional robots. UR5 is the first robot developed according to the requirements of co-robots from the beginning of product design.

Shortly thereafter (2008), renowned robotician Rodney Brooks founded Rethink Robotics. Its original purpose was to help local SMEs in the United States improve production efficiency, reduce costs and reduce offshore outsourcing. The initial launch of the two-armed Baxter was not very successful, slowly falling behind UR. A new one-armed Sawyer robot was introduced last fall, and it remains to be seen how well it will be received.

After UR and Rethink, a large number of newly established co-robot companies (such as Shenzhen Techrobots) have grown up. There are more and more collaborative products on the market, and the concept of co-robot has been gradually recognized and accepted by everyone.

The differences between co-robots and traditional six-axis robots

Co-robots are also industrial robots, but what are the technological differences compared with traditional six-axis robots? "In the robot industry applications, the traditional six axis robot is widely used in automobile, 3 c industries, these industries belongs to large OEM enterprises, production line, mature, stable industry, in very high risk of producing a year, engineers programmed, it is ok to start production directly, pay attention to the efficiency of the application, like this you must use the six axis robot," wang said, "and in the process of promoting and found a lot of small businesses, such as integration, on the production line in production is very frequent, for these small and medium-sized enterprises, their demands are more hope can change frequently, easy to operate. The most important thing is safety. Traditional robots need to be surrounded by safety fences. There are many accidents every year and a large amount of cost is needed in the safety system.

To sum up, the difference between the two is that the traditional industrial robot is a single variety, mass production; Co-robots are customized, multi-variety, small batch production. So co-robots have to satisfy several characteristics: easy to use, safe, and low cost. Be able to autonomously plan graphic programming, drag teaching, reduce system integration training, programming maintenance costs; Safety design, reduce hardware protection investment, reduce floor space to reduce safety investment.

Distribution of major co-robots in the market

The first generation is based on the transformation of traditional robots. This kind of co-robot is based on the existing models, with a large choice of load and arm spread, and a wide variety of detection means. However, the speed caused by self-weight must be very slow, and there are certain defects in precision and safety. The old product design idea is inconsistent with the cooperation, and the cost of reconstruction is high, which is not quite consistent with the concept of man-machine cooperation.

In the second generation, the cost/performance balance is better, and the mass production and known as the co-robot. For example, co-robots such as UR, which have a large market share, are characterized by lightweight, low voltage and small load. They are relatively safe varieties of traditional robots with simple structure and low requirements for control and planning, which can meet the requirements of general material handling, positioning and loading and unloading of machine tools. However, there are many problems in price, ease of use, flexibility and security.

Third generation, evolutionary version of co-robots. The co-robot represented by ABB has accurate manipulator dynamics model, accurate transmission model and vibration compensation. The torque free sensor reduces the influence of friction and inertia on drag, collision and force control to a sufficient level by greatly reducing deadweight and load. However, the design of this cable inside is not the motor of a heavy industry, and the direction of the cable is relatively complex. The design principle determines that it is impossible to make a model with large load, and the actual landing needs to be improved.

The fourth generation, SEA based flexible robot. , the intermediate version of the bionic arm on the road, and the next generation of co-robot technology with better cost and performance balance.

This robot has a flexible every joint of sensor, the position of the first three generations in the traditional control, are controlled at the end of the robot, from one point to reach a certain point, according to timing control, to a high or low point, direct force control, which can realize high dynamic force control, high sensitive drag teach/collision detection; The closed-loop feedback of sensors in each joint is really used to realize control detection. These robots are a kind of robot that we believe can achieve force control flexibility well with force sensors added in the joint.