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According to data from Harris Williams in its "Industrial Automation Sector Update 2021", the value of the global automation market in 2020 was approximately US$175 billion. It is expected to reach approximately US$265 billion by 2025. The market of China, the world's factory, is expected to be worth NT$208.5 billion by 2022. Clearly, industrial automation is growing globally at an accelerating rate.

Essentially, industrial automation technology is the use of control theory, instrumentation theory and computer information technology to achieve detection, control, optimization, scheduling, management and decision-making of industrial production processes. It is a comprehensive technology that aims to increase output, improve quality, reduce consumption and ensure safety.

The new norm of the global pandemic has significantly impacted labor-intensive industries in industrial manufacturing. The entire market is experiencing increasing urgent demand for both automation and smart solutions.

Figure 1. Global automation market value statistics and estimates (Image source: Harris Williams)

Servo control is the foundation of industrial automation

For a factory, having industrial automated precision manufacturing and flexible manufacturing production lines is almost mandatory for smart and innovative enterprises. The servo system is the core technology for realizing both industrial automated precision manufacturing and flexible manufacturing, as well as the main source of power for industrial robots.

It is common knowledge that the first requirement of an enterprise in the process of transitioning to smart manufacturing is to increase productivity and production efficiency. However, this often requires the aid of advanced equipment. For high-end equipment manufacturing industries that employ robots and CNC machine tools, and electronic manufacturing, the equipment requires precise control of motion elements such as displacement, speed and torque. The high-precision servo system is the key to achieving precise control.

Figure | Schematic diagram of precision manufacturing

Like most industrial automation systems, the servo system consists of three main parts: the controller, servo driver and servo motor. Unlike other industrial automation equipment, which struggles to recalibrate and compensate for faults and errors as soon as problems occur, the servo system can be continuously optimized. Furthermore, it can also control each link with greater precision, even to the extent of the micron level.

On the one hand, the servo system can achieve precision control in precision manufacturing and accelerate production while improving production quality, all of which contribute to improving work efficiency and output value. On the other hand, it can reduce dependence on the processing precision of mechanical parts and the operational precision of the transmission mechanism by improving control precision and efficiency, thus decreasing the manufacturing cost of precision equipment.

Drones are "flying" into industrial automation

In industrial automation applications, drones are helping to actualize the important "unmanned" and "automated" links. They are able to conduct maintenance, take measurements, survey and monitor production. Their usefulness increases as the resolution of the images they capture continually improves. Data collected by drones, combined with analysis software, can provide us with ever more detailed analysis, management, maintenance and prediction capabilities.

Drones must have sophisticated servo control systems to complete various fine-movement flight tasks. You can think of these systems as the drone's brain. For example, to achieve the level of control required for competition-level drones, four high-performance microcontroller units (MCUs) are required to control the four brushless direct current (BLDC) electronic speed control (ESC) motors of a quadcopter drone. A Cortex-M4 MCU is used to control flight and complete tasks such as reading sensor data, controlling flight attitude and facilitating communications.
 

The i.MXRT1052 processor launched by NXP Semiconductors can drive four brushless motors with a non-inductive field-oriented control (FOC) algorithm through external 4-channel power modules. It can complete tasks while using just one MCU. This in turn can reduce the overall manufacturing cost along with the size of the system, opening up exciting new pathways for drone development.

Since this processor has a processing power comparable to that of an MPU, it can support peripheral functional interfaces like LCD, Camera, USB, UART, CAN, Ethernet and PWM. This allows it to easily process the sensor signals, including video data as well as the data returned by accelerometers, gyroscopes, magnetic compasses, and barometric sensors. The processor computes and processes this data to coordinate communications over various channels.

In addition, i.MXRT1052 comes with an integrated DC-DC converter. What’s more, its UART interface can be used to transmit analog signals for speed control in order to achieve high-precision control of position, speed, and motor armature current of the AC motor.

In STMicroelectronics’ drone solution, the STM32G4, three hardware accelerators have been added. These include the adaptive real-time (ART) accelerator that implements code acceleration, the key program acceleration CCM-SRAM (Core Coupled Memory) that implements pre-configured deterministic guarantees, and the mathematical accelerators involving trigonometric functions and digital filters. This configuration ensures that the sensor returns data at high speeds when the processor's predominant frequency resources are insufficient.

Figure | Discovery kit B-G431B-ESC1 based on STM32G4 (Image source: STMicroelectronics official website)

STMicroelectronics also provides a full-featured motor-speed electronic control discovery kit that is capable of handling sensorless field-oriented control (FOC) algorithm or six-step commutation control. Its on-board functions support motor sensors and three-shunt resistor-based current detection. Together with the X-CUBE-MCSDK v5.4.1 motor control SDK, it can realize the electronic control of motor speeds for drones powered by up to 6S LiPo battery packs.

In the future, next-gen technologies such as AI, big data and edge computing will continue to take industrial automation to new levels. The realization of its enormous potential of course requires deep industry knowledge and experience – and a fleet of drones!