“Over the past few years, a range of new end markets and applications have begun to emerge, driving the need for higher performance position sensors. This is particularly evident in the field of magnetic position sensor ICs, where suppliers of such sensors have responded to the market’s urgent call to launch new products tailored for the rapidly growing robotics and drone market.

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Over the past few years, a range of new end markets and applications have begun to emerge, driving the need for higher performance position sensors. This is particularly evident in the field of magnetic position sensor ICs, where suppliers of such sensors have responded to the market’s urgent call to launch new products tailored for the rapidly growing robotics and drone market. The new magnetic position sensor is smarter, offers higher resolution and accuracy, is smaller and lighter, and consumes far less power than its predecessor. This article will briefly describe the history of magnetic position sensors, the end markets and ways they have served in the past, and then delve into the special new features and capabilities introduced in today’s new generation of devices. Finally, focusing on robotics and drones, we share a few use cases for these new and innovative magnetic position sensors.

Hall magnetic position sensors have been around for a long time, but as the end markets for automotive, consumer and industrial applications continue to electrify, their use in these applications is still increasing today. For example, in the automotive field, magnetic position sensors are currently used in vehicle subsystems such as steering, braking, transmission, shifters, ride height, pedals, fuel level sensing, etc. And the proliferation of self-driving vehicles will only boost their usage demand. In the consumer sector, they are widely used for door position detection in white goods. In the industrial market, they are used to provide actuator, lever and joystick position feedback for control systems and industrial robots. In addition, they are heavily used for auxiliary motor control in all markets.

The main reason why magnetic position sensors are so widely used is that they can be implemented with low-cost CMOS semiconductor technology and can provide accurate, repeatable, and reliable position measurements in the harshest environments. Magnetic position sensors are immune to dust, mud, dirt and liquids, and can work in high temperature, high humidity environments. Some suppliers, such as ams, even offer magnetic position sensors that are immune to stray fields.

CMOS magnetic position sensors have been incorporated into a variety of common surface mount and single in-line through-hole IC packages that are small enough for most of the applications mentioned above. Likewise, the typical power consumption of a CMOS magnetic position sensor is in the tens of milliamps. This is still an affordable level of power consumption for the traditional automotive, industrial and consumer markets.

However, with the rapid electrification of cars, new consumer products connected to the Internet of Things emerging, and industrial equipment and factories becoming more efficient and intelligent through the use of robotics and artificial intelligence, the magnetic position sensors of the past are no longer suitable. Today’s designers generally believe that they are too large in physical size and power consumption, and not accurate enough to meet the system’s performance goals.

Design engineers currently working on new types of robots for end markets such as light industry, medical and space exploration feel the same way about traditional magnetic position sensors. In all three end markets, robotic designers need ultra-compact and ultra-low-power magnetic position sensors to produce very small, high-precision robotic arms. Robotic arms will be used to perform intricate tasks such as assembling Electronic components, performing various laparoscopic surgeries, and picking up samples of small minerals and sediments on distant planets.

The same is true for the rapidly growing UAV market, where size, weight and low power consumption are key requirements to achieve longer flight missions. In the field of UAV camera gimbal, ultra-small and ultra-low power magnetic position sensors are especially important. essential. The magnetic position sensor is used in the camera gimbal of the UAV, providing commutation feedback for the brushless DC motor of the gimbal, and providing three-dimensional gear angle position feedback. Without these magnetic position sensors, the camera isn’t stable enough to deliver stunning photography.

Fortunately, magnetic position sensor suppliers are responding to the needs of customers and these new end markets with a new generation of magnetic position sensors. The new magnetic position sensors are available in ultra-small packages, including a wafer-level chip-level package (WLCSP), which is nearly the same size as the sensor die itself, and these position sensors automatically enter a low-power mode to reduce overall power consumption.

For example, ams offers two devices that meet these new needs. The AS5510 linear position sensor is packaged in a WLCSP with a size of only 1.46mmx1.0mmx0.6mm and features a low-power mode that consumes only 25μA of current. Likewise, the 12-bit precision AS5055A is available in a small QFN-16 package (4.9mmx6.0mmx1.75mm) and has a low power mode that consumes only 3μA in this mode. These features make the AS5055A widely used in motor control systems that require ultra-small size and ultra-low power consumption. This product is currently widely used in motor control for a variety of end-market applications, including industrial and consumer applications and robotics for interplanetary space exploration. ams also offers a variety of system-in-package (SiP) solutions for magnetic position sensors, where the sensor and associated decoupling capacitors are integrated in the same package, enabling a “PCB-free” design for lower System cost and smaller form factor solutions.

ams has also recently started offering samples of its latest magnetic angular position sensor, the AS5600L. This product offers 12-bit output resolution at -40 to 125^oThe maximum INL (integral nonlinearity) error over the entire operating temperature range of C is only1^o, in a WLCSP (2.07mm x 2.63mmx0.6mm) package and consumes only 1.5mA in automatic low power mode. Below are two example simulation plots of the INL error of the AS5600L with a gap (Z) of 1.5mm and an X/Y deviation of no more than ±1mm between the target magnet and the sensor itself. As can be seen in the figure, both target magnets can achieve an INL error o at zero X/Y deviation.when the gap

Magnet (diameter 4mm, thickness 2mm) Magnet (diameter 6mm, thickness 2.5mm)

Figure 1.0

This low INL error or high accuracy results, along with low noise and ultra-low power consumption over a wide temperature range and target magnetic flux, enables ultra-compact Hall-effect based magnetic position sensors such as the AS5600L to meet the demands of today’s robotic and unmanned systems. Machine design engineers need performance and space. Additionally, they offer cost advantages over competing position sensor technologies.

Robot designers are leveraging a new generation of magnetic position sensors to develop robots with smaller, more flexible limbs for a variety of end markets, including medical, light industry, and geology and space exploration. Robots with small limbs can pick up and move objects faster and more precisely in applications such as performing light industrial electronics assembly tasks, enabling robotic laparoscopic surgery, and even picking up small soil samples on distant planets. Specifically, they are using magnetic position sensors to provide joint motor commutation and gear position feedback.

To realize these small robot arms, mechatronics design engineers are using flexible printed circuit boards to mount these small magnetic sensor ICs on the main controller of the robot body to provide power and transmit data signals back to the main controller in the robot body. main controller. See Figure 2.0 below.

Figure 2.0

Similarly, a new generation of magnetic position sensors is also used in the field of drones. Drone designers are developing new three-axis camera heads that incorporate many of the same technologies found in smartphones to keep the camera stable for great shots. However, it is the use of ultra-small and low-power magnetic position sensors that play a key role, providing three-axis position feedback from the camera head’s brushless DC motor and gears to ensure the camera is always level and vibration-free while flying and shooting . See Figure 3.0.

Figure 3.0

All in all, a new generation of high-accuracy, small-size, and low-power magnetic position sensor ICs enables today’s electrical and mechanical design engineers to develop new, powerful robots and drones that serve many new markets and applications. In the near future, we can expect to see small medical robotic arms actually pierce the human body, maneuvering adeptly to remove tumors and perform other surgeries. In the industrial robotics market, we expect to see lightweight smart manufacturing robots used to perform more complex and delicate tasks such as electronic assembly. In the UAV space, we will continue to see the development and improvement of cameras and payload gimbal to support higher resolution photography and complete higher precision 2D and 3D mapping.