Nidec's Technological Capabilities Take on the challenge of new servo technology

We will take on the challenge of building new servo skills that can cope with large-scale and high-precision control equipment.

The automation of the production line has brought a lot of convenience, and the automation of all production processes such as processing, transfer, and assembly is constantly being carried out. In this process of automation, production skills are also rapidly developing as the core of automation. However, if the level of control targets such as robots and active devices is required to increase, the required standards cannot be met according to the existing control skills, and the existing skills cannot be corresponded.

In the past, it was mainly used to control robots and other devices, such as a numerical control algorithm called a PID manipulator. The control system responds to and corrects the three items of P (share), I (integral), and D (derivative) according to the error of the satisfactory target value and the actual control target value. The method of starting planning without rigorous verification of the control target was selected, and the method of adjusting the parameters of the controller was repeated while repeating the operation test. Since there is no problem with the responsiveness of analog/hardware control equipment, it has been used in a wide range of industries, from the active operation of aircraft to motors and hydraulic systems, as well as automobiles, petrochemicals, and electric power. However, as the number of control devices increased in the direction of mass and precision, the number of controllers increased, and many hours were required to repeat the experiment, and there were cases where the required standards did not meet the required standards.

With the large-scale development of robots and other controlled targets, PID control systems, which have been widely used in major industrial fields, are bound to develop in the direction of large-scale and high-precision. The PID control system at that time will not be able to meet the requirements of future control skills

There is one type of robot that is one of the targets that cannot be controlled by PID manipulators. Japan Densho Sankyo has developed and manufactured various robots, among which the most important development is a robot for transferring liquid crystal glass substrates. In order to complete the large-scale of the final product and the progress of production power, the size of the original glass of the base material master of the LCD screen is also increasing year by year, and the latest model is larger than 3 tatami mats. In order to transfer this very thin and large master glass, even the transfer robot needs to be precisely controlled. This is because rough manipulation can cause the original mother glass to shatter. The problem with these robots for transferring large liquid crystal glass materials is that they tend to shake easily due to the drop in the mechanical resonance point, and the load changes dramatically depending on the elastic movement of the arm and the presence or absence of load. Despite these challenges, it is necessary to improve accuracy and speed in order to increase production power.

Nidec's Technological Capabilities Take on the challenge of new servo technology

With the development of liquid crystal transfer robots in the direction of large-scale, the control effect of the PID manipulator can no longer meet the required standards

In order for large robots to operate with high precision and high speed, the following standards must be met.

Closed-loop characteristics: The need for closed-loop characteristics to fit (fit) the declining mechanical resonances.

Characteristics to deal with external disturbances: Reliable operation is required even for large load changes and external disturbances.

Instruction response characteristics: Instruction response characteristics that are aimed at increasing power by demand progression.

These are the opposite requirements of the original situation, and in order for large robots to operate with high precision and high speed, it is necessary to set these opposite requirements independently in a comfortable control mode. This is not possible with a parameter-adjusting controller such as the conventional PID controller. Therefore, Japan Denco has developed a new control method based on the modern control theory of "mathematically embodying the control target and planning a numerical control algorithm device that fits the mathematical form to reflect the model". In addition, starting from the concept of solid economic manipulation, such a method is considered, that is, the rough calculation model is used to reflect the uncertainty and change part by not using the detailed modeling of the control target, and the external disturbance observation and compensation function of solid economic application is exerted in the set frequency range, so that the uncertainty and change part are more stable. On this basis, the closed-loop characteristics are combined with the demand model that fits the mechanical characteristics, and the instruction response characteristics are improved according to the feedforward control. In this case, it is also possible to set the response characteristics of instructions freely by implementing feedforward compensation based on the closed-loop characteristics matched by the model.

Japan Densan Sankyo's model-matching servo technology overcomes the shortcomings of conventional PIDs, such as repeated test adjustments, slow detection speed, and areas where vibrations occur

Nidec's Technological Capabilities Take on the challenge of new servo technology

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