What Role Do High-Precision Sensors Play in Creating Natural Movement in Robots?

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The service robot market is about to take off

Robots that perform tasks in place of humans are playing increasingly active roles in a variety of settings like manufacturing, logistics, medical, welfare and homes. The range of robots is expansive, including factory automation equipment, Automated Guided Vehicles (AGVs), customer service robots and nursing care robots. For the home, there are even “communication” robots designed to provide healing and entertainment.

Robots can be categorized into two types: industrial robots and service robots. Industrial robots operate in factories and other manufacturing facilities, performing predetermined tasks on behalf of humans in environments isolated from humans. Service robots, on the other hand, perform functions like customer service and nursing care, and work mainly in public spaces like stores and offices in the proximity of people. For service robots and people to coexist, ensuring safety is a must.

Service robots are being adopted widely around the world. As sensors and systems evolve, new types of robots are expected to emerge and become increasingly familiar in our daily lives.

The role expected of sensors in robots

Among service robots, “companion robots”^*1 are designed to play the role of pets or family members at home. Thanks to their AI-based conversational functions and fluid movements, one might even forget they are machines at all. Because the spread of Covid-19 has restricted the amount of contact between people, these robots are now drawing attention as one means to alleviate feelings of loneliness.

Indispensable to the smooth, natural movements in these robots are the performance of motors along with components known as motor controllers and angle sensors. Moving parts of the robot like the arms, torso and wheels are equipped with small servo motors; their movements are coordinated precisely by the controllers. Angle sensors accurately detect the angle and speed at which they rotate.

For a small companion robot to move naturally and accurately, the best torque response from the motors must be brought out through highly accurate angle detection and fast response times. High-precision angle sensors and compact embedded controllers play crucial roles in this. TAS/TAD series of sensors are broadly used among service robots and other applications.

Robots that autonomously roam around a room need to accurately detect the external environment, including the size of the room, surrounding objects and the movement of people. To this end, the latest companion robots are equipped with numerous sensing components like cameras, microphones, temperature sensors and luminance sensors. Technologies for making sensors smaller, more accurate, and more reliable are essential to the high performance of robots.

TMR sensors^*2 are highly precise, extremely reliable magnetic sensors used to detect angles in robotic motors. They can sense a rotating body’s angle, position and other conditions across a wider temperature range and with higher precision than conventional sensors. Besides robotic motors, they are widely utilized in settings where high-precision magnetic detection is required, such as angle detection in electric vehicle motors, electric power steering (EPS) systems and autofocus in smartphones.

A TMR sensor detects the angle of rotation of a motor

The remarkable capability of high-precision TMR sensors

TDK’s TMR sensors are magnetic sensors that utilize TMR (Tunnel Magneto Resistance) elements. They were originally developed as angle sensors for automotive and other applications. These products are packed with TDK’s know-how on magnetic and thin-film technologies, and feature high precision, high reliability and favorable temperature characteristics.

TMR sensors operate reliably across a wide temperature range, which is why they are broadly utilized in automotive applications where precision and reliability are paramount. They also feature low power consumption and are employed in consumer products like robots and smartphones as well.

TDK’s high-sensitivity TMR sensors can be valuable for controlling just about anything that runs on motors. They empower future industries and our daily lives with high precision and reliability.

TAD2141 TMR Angle Sensor

TDK’s TAD2141 TMR sensor is a thin-film element composed of two ferromagnetic layers that sandwich an insulator layer as thin as one to two nanometers (a nanometer is one-millionth of a millimeter). The TAD2141 offers robust noise resistance, high output and outstanding angular accuracy and stability in a small package. The TAD4140 features two sensor elements and two discrete output systems, ensuring the high level of redundancy required for automated vehicles. For more information about our products, please visit the Product Center.