In a world where electric motors rotate, how can we explore a more elegant movement posture?

From the Hu Xuan dance that was popular in the Tang Dynasty of China to the ballet that has been admired by the world for centuries, rotation is an important part of dance aesthetics and art. The dancers' clothes flutter and their postures are charming, which enhances the aesthetics and appreciation of the whole dance. The dancers' rotation brings artistic sublimation to the basic motion state of the physical world. Modern science's research on rotational motion has brought about a century-long industrial revolution in dynamics and kinematics, and power equipment based on electric motors has become the foundation of modern industry.

Nowadays, motors have become ubiquitous in modern industry, medical treatment, smart home, IoT, transportation, office, etc., and have penetrated into every aspect of life. The artistic control of dance rotation is the improvement of the dancer's artistic and aesthetic performance, and the control of motor rotation is bringing more convenience and comfort to life with the wisdom of science and technology. Especially in today's digital process, digital information can be converted into precise physical movement, and previously unfeasible scenes are gradually becoming a reality, such as advanced robotics, the Internet of Things, additive manufacturing, prosthetics, and IIoT. Just as the graceful rotation of dancers requires years of training, effectively converting digital information into perfect physical rotation faces many challenges: it requires optimized software and hardware components to optimize performance; it requires as low power consumption as possible to achieve a longer battery life cycle and lower heat; as little software workload as possible to shorten the time to market for products; as high integration as possible to improve product stability... In fact, this is also the key goal achieved by Trinamic motor motion and control solutions of ADI, a high-performance semiconductor solution provider, in recent years. The company's innovation in many key technologies has promoted breakthroughs in motor applications.

The application of motors in prosthetic limbs helps reproduce the beauty of life movement with the beauty of technology. (The world's first prosthetic limb with two movable joints based on ADI Trinamic motor control technology was used at the Cybathlon, the global cyborg Olympics held in Zurich)

How to deliver a glass of beer "elegantly"? The technical "know-how" behind this is very important

The dancers' rotational movements are smooth and graceful, so how can the rotational movement of the motor be controlled freely? The following figure shows ADI Trinamic's demonstration of moving a beer glass with ordinary motor movement, which causes the beer to overflow (Figure b.). ADI Trinamic's "S"-shaped ramp acceleration curve is used to quickly move a glass full of beer between two points (Figure a.) without spilling a drop of beer. The seemingly simple motion state comparison is actually very critical to many application fields. The same principle also applies to robots used in medical research or other liquid handling applications, etc. From tissue analysis to blood centrifugation and liquid handling, fast and smooth motion control provides a simple solution.

Compare the effects of quickly moving a glass full of beer using motor motion.

For this type of application, if you want the motor to run smoothly, designing a good motion control trajectory curve is equivalent to completing half of the perfect motion control. The motor's motion trajectory curve includes trapezoidal curve and S-curve. Compared with the trapezoidal curve, the S-curve is smoother, overcomes the disadvantage of the former's acceleration mutation, and can more effectively reduce the impact. ADI Trinamic implements traditional software algorithms through hardware, thereby saving the burden on the CPU, making the originally complex S-curve easy to implement, and reducing the workload of production and research and development.

The motion trajectory curves of the motor include trapezoidal curves and S-shaped curves. Compared with the trapezoidal curve, the S-shaped curve is smoother.

ADI Trinamic has two major technical patents for stepper motor driving, StealthChopTM and CoolStepTM. By continuously adjusting the acceleration and deceleration rates of the robot arm, the protruding points in the speed curve are avoided to reduce system jitter. The "S"-shaped slope enables it to reach a higher speed and still accurately reach its next position, with minimal interference to its payload, making the stepper motor run more smoothly, more energy-efficient and efficient. These algorithms can also help industrial material transport vehicles move heavy loads quickly and efficiently. In the absence of a feedback device, the stepper motor can still achieve speed control and positioning control. It has the advantages of good rigidity, high reliability, and high cost performance. It is widely used in production line transmission, engraving, textiles, security, medical and other fields.

In addition, in high-speed applications, servo motors such as BLDC (brushless DC motor) and PMSM (permanent magnet synchronous motor) have more advantages. FOC (field oriented control) is the most efficient control method in servo control. ADI Trinamic's hardware-based spatial magnetic field vector control can accurately control the size and direction of the magnetic field, making the motor torque stable, low noise, and quick to respond, thereby improving the motor efficiency and accuracy.

“As fast as a rabbit and as quiet as a virgin”, how can motor applications be “both dynamic and quiet”?

Just like the aesthetics of dance, the dynamic beauty of fast rotation and the gentle beauty of slow movement changes, or the quiet beauty of abrupt stop, bring different artistic perceptions. In motor applications, there are also many fields that require "both static and dynamic" - especially in scenes such as office, home, and medical treatment. People's traditional impression of the noisy characteristics of motors makes people want to stay away from them, and the silent characteristics of motors in operation are very important.

Take the increasingly popular 3D printing as an example. This type of lightweight and convenient equipment is mainly used in non-traditional industrial manufacturing plant environments such as offices. During the hours of operation, any noise will cause a very negative experience. Anxiety about noise has become a common topic in this industry: "3D printers are very loud, and it is difficult to be in the same room with them when doing anything efficient."; "When printing at low speeds, the whole thing vibrates and makes noise."; "I didn't expect them to be so noisy, is this normal?"... These are just a few of the complaints on the RepRap forum, a well-known 3D printing open source community in the industry, and everyone hopes to find the best solution for 3D printing silent motor control. In fact, patients in quiet wards cannot tolerate the obvious noise of infusion pump motors. Similarly, at home, you can hardly tolerate the annoying buzzing of the sweeper when sweeping indoors. The same scene where people demand quiet working equipment also appears in video conferencing, smart homes, laboratory automation and desktop CNC equipment.

All of these applications make extensive use of stepper motors. However, the disadvantage of steppers is that they are noisy, especially at low speeds or when stationary, due to vibration. There are two main sources of vibration in stepper motors: the step resolution, and side effects caused by the chopper and pulse width modulation (PWM) mode.

The first 3D printer to use Android, based on a solution with StealthChop silent motion control technology, means the 3D printer can be integrated into any home or office.

Low-resolution stepping modes such as full-step or half-step are the main source of noise in stepper motors. They introduce huge vibrations, especially at low speeds and close to certain resonant frequencies. To reduce these vibrations, a mechanism called microstepping can be applied to divide a full step into a smaller number of microsteps, with the maximum resolution defined by the A/D and D/A functions of the driver. ADI Trinamic's stepper motor controllers and drivers allow the use of up to 256 (8-bit) microsteps per full step, using the chip's integrated configurable sine wave table or even completely customized current waveforms to make the motor rotor step at a smaller angle or shorter distance. When driving some inferior stepper motors, ADI Trinamic opens the function of automatic adjustment of the internal subdivision table to users.

Another source of noise and vibration comes from the traditional chopper and PWM modes commonly used in stepper motors. The parasitic effects of these modes are often ignored due to the main influence of coarse step resolution. However, as the step resolution is increased using microstepping, these parasitic effects become more obvious and even audible. Advanced current control PWM chopping modes such as SpreadCycle™ automatically configure a hysteresis decay function between slow and fast decay. The average current reflects the configured normal current, and there is no transition period at the zero crossing of the sine. This reduces the fluctuation of current and torque and makes the current waveform closer to a sine wave. Compared with the traditional constant chopping mode, the motor controlled by SpreadCycle PWM chopping mode runs much more smoothly and can reach higher speeds, thereby achieving high dynamic motor control.

Based on ADI Trinamic motor control drive solution, the system's electromechanical actuator is completely silent to achieve high-fidelity Dereneville DTT-01-S active linear tracking turntable design