To realize the next generation of robots, several key sensor technologies play a very important role, including magnetic position sensors, presence sensors, gesture sensors, torque sensors, environmental sensors, and power management sensors.
Magnetic position sensor promotes robot revolution
One of the most common sensor technologies in today's consumer, service, social, and even industrial robots is the magnetic position sensor integrated circuit (IC). Today, almost every consumer, service professional, or social robot is used in every joint. Two or more magnetic position sensor ICs. At least one magnetic angular position sensor is used for each rotation axis or joint rotation. Many robots today use small but powerful brushless DC motors (BLDC) to move robotic joints and limbs. In order to drive the motor correctly, motor position feedback is needed.
There are more and more magnetic angle position sensor ICs used to provide motor commutation feedback for joint motor controllers (see Figure 1). In addition, closed loop motor control of robot joints also requires gear angular position feedback. Therefore, robot joints Each of the two axes of motion requires two magnetic angular position sensors. For example, if the robot's pedals must be moved in pitch and roll axially, a total of four magnetic position sensors must be used. Since each joint requires this multiple Sensors, and most robots have many joints, therefore, it is very obvious that nowadays a new generation of robots have adopted magnetic angle position sensors.
Figure 1 Robotic Arm with Magnetic Position Sensor
Compared to other position sensor technologies that were used in robotic joints in the past, today's latest magnetic angle position sensors offer many advantages. These new magnetic angle position sensor ICs provide high resolution and repeatable accuracy. In addition, due to their Manufactured on a CMOS silicon process, these new magnetic angle position sensor ICs require minimal power, weight, and space compared to other position sensor technologies such as optical encoders and resolvers. Furthermore, magnetic position sensor ICs can Working in very harsh environments, including extreme temperatures, dirty and dusty environments. Some magnetic position sensors are not even affected by common magnetic stray fields in robotic working environments. Finally, because they are non-contact, and Mobile mechanical parts, so they do not wear out, unlike the resistive potentiometers commonly found in traditional servomotor components used in low-cost social/toy robots. Thanks to these advantages, magnetic angular position sensors are widely used in today's consumption. Sexual, professional services and social robots are now even used for industrial robots.
Information Fusion Achieves Spatial Visual Sensing
There are several existing sensor technologies that are being integrated into today's robots, and their information is fused together to provide spatial visual sensing of robots, as well as object detection and avoidance obstacles. 2D and 3D visual stereo cameras It is common in many new consumer and professional service robots today. However, there are new advanced sensor technologies, such as Time of Flight sensors including light detection and ranging Lidar sensors. It is also being used in robots. Optima provides high-resolution 3D mapping of the robot's operating space and surrounding environment, enabling it to perform tasks and move better (see Figure 2).
Figure 2 Lidar Mapping
Ultrasonic sensors are also used for presence sensing. Just as they are used in reversing security alarm systems, ultrasonic sensors in robots are also suitable for detecting nearby obstacles to prevent robots from hitting walls, objects, other robots. And the human body. In addition, these ultrasonic sensors can also play a role when the robot performs its main function. The ultrasonic sensor plays an important role in near-field navigation and obstacle avoidance, which can improve the overall efficiency and safety of the robot.
However, the sensing range of ultrasonic sensors has its limitations, which are approximately 1 cm to several meters, and the range of cones up to approximately 30 degrees. Their cost is relatively low, and accuracy in close range Higher, but as the ranging range and measurement angle increase, the accuracy decreases. They are also susceptible to changes in temperature and pressure, as well as interference from other robots using the same frequency ultrasonic sensors. However, when compared to other When existing sensors are used in combination, they provide useful and reliable position information.
When all the presence sensors (2D/3D cameras, light, and ultrasound) data are fused together, as we have seen in high-end consumer/professional service robots and industrial robots, these robots have outstanding spatial awareness. Ability to move and perform more complex tasks without harming yourself, humans and the environment.
Gesture Sensors Help Human Interaction
There are more and more gesture sensors integrated into today's most complex robots to provide user interface instructions. Gesture sensor technologies include optical sensors and control arm sensors worn by robot operators.
Using optical-based gesture sensors, robots can be trained to recognize specific hand movements and perform specific tasks based on specific gestures or hand movements. These types of sensors open up many opportunities for physically impaired people with limited communication skills in homes or hospitals. , also provide many assistance in the smart factory.
Using an armband control sensor, the wearer can communicate and control with a collaborative, industrial, medical or military robot, enabling the robot to perform and simulate specific tasks based on the operator's movement patterns and arm position. For example, each arm wears one arm The surgeon with the sensor can control the telemedicine robotic arm to perform surgery, and the arms may be farther from the other side of the globe.
Torque sensor provides monitoring
Torque sensors are also increasingly used in today's next-generation robots. Torque sensors are used not only for the robot's end effectors and fixtures, but also for other parts of the robot, such as the trunk, arms, legs and head. Etc. These special torque sensors are used to monitor rapid body movements, detect obstacles and provide safety alerts to the robot's central processor. For example, when a torque sensor in the robot's arm senses that the robot's arm has collided with an object Sudden and unexpected external forces, its control security software can stop the arm and retract it.
Torque sensors can also work with presence sensors, as well as other safety monitoring sensors, such as environmental sensors, to provide monitoring of the overall safety zone.
Environmental sensor protection work safety
Various environmental sensors are also looking for ways to enter industrial and consumer robots, including environmental sensors that detect volatile organic compounds (VOCs) that affect air quality, temperature and humidity sensors, pressure sensors, and even It is a sensor that can detect the presence of lighting. These sensors not only help ensure that the robot can continue to operate effectively and safely, but also allow people within the robot's working range to perceive unsafe environmental conditions.
Power Management Sensors Improve Efficiency
Power management sensors have also been integrated into today's robots to help extend the robot's working time between charges and ensure that the most commonly used lithium-ion batteries in automatic robots do not overheat when they are charged or discharged. Sensors are also used for voltage regulation and power and thermal management of robotic joint motors. All on-board electronic components, such as microprocessors, sensors and actuators, require low-noise chopper power and voltage regulators to ensure It can operate efficiently and correctly.
The latest sensor solutions for robot power management include coulomb counting for battery discharge and charging, accurate and reliable overheat monitoring sensors for regulators, and current sensors for battery management devices.
Thanks to the integration and integration of these innovative sensor technologies, today's latest robots can operate more independently and safely. In addition, computing capabilities, significant advances in software and artificial intelligence, and collocation with these new sensor technologies, make the next generation of robots It can be more easily used to support various applications. Furthermore, they can complete tasks more accurately and more quickly than previous generations of robots. Finally, they can be more independent in more home, business and manufacturing environments. Work and collaborate more safely with humans.