Tactile sensors for industrial robots help them measure any physical interaction with their environment. The sensors measure parameters related to contact between the sensor and the object. Industrial robots also benefit from tactile sensing. Force and tactile sensors enable robots to manipulate objects with greater precision and sensitivity in environments with smaller structures.
Tactile sensors are designed based on the biosensory experience of touch and can detect mechanical stimuli, stimuli of temperature, and pain. Tactile sensors receive and respond to signals of force or physical contact.
Several different types of tactile sensors are used in a range of applications, such as those sensing normal pressure and dynamic tactile sensing. They are among the most commonly used sensors in robotics, including piezoelectric, piezoresistive, capacitive, and elastic types. This article will primarily introduce the functions and types of tactile sensors used in industrial robots.
1. Optical Tactile Sensors: Optical tactile sensors come in two types: internal and external. In this type, the intensity of light is adjusted by moving an obstacle into the optical path. It has the advantages of being resistant to electromagnetic interference and has high resolution. It requires low wiring, and electronic devices can be located away from the sensor.
2. Piezoelectric tactile sensor: When pressure is applied to the sensor element, the voltage effect across the element is piezoelectric. The voltage generated is proportional to the applied pressure. In this case, no external sensor is required. The advantages of this type of sensor are durability and a wide dynamic range. It can measure pressure.
3. Resistive Tactile Sensor: This sensor operates based on the change in resistance between a conductive polymer and electrodes. This type of tactile sensor is widely used. When pressure is applied, the resistance of the conductive material changes. The resistance is then measured. This sensor offers advantages such as high durability and good overload tolerance.
4. Capacitive Touch Sensor: The capacitance change between two electrodes is used in capacitive sensors. This type of capacitive sensor measures capacitance, which changes under applied pressure. The capacitance of a parallel-plate capacitor is related to the spacing and area of the plates. The capacitance changes according to the load. This sensor has the advantages of linear response and wide dynamic range.
5. Magnetic Tactile Sensor: The magnetic tactile sensor employs two methods: one is to measure changes in magnetic flux density, and the other is to measure changes in the magnetic coupling deformation between windings. This sensor has advantages such as high sensitivity and no mechanical hysteresis.
The role of tactile sensors in industrial robots
In industrial robot operation technology, vision and touch, much like in the human realm, are complementary modes. Industry experts predict that vision technology will soon be added to mainstream robot applications. Essentially, an industrial robot's tactile sensor is a touch sensor that can provide information about the object it touches. This information is about the shape, size, and type of the object being touched.
Industrial robot tactile sensors can detect the presence of objects. They can also determine the shape, position, and orientation of parts. The contact between the object and the sensor is pressure, thus the pressure distribution can be determined. This device can perform object inspections such as texture monitoring, joint inspection, or damage detection. Industrial robot tactile sensors can detect various stimuli, detect the presence of objects, and obtain tactile images. Tactile sensors have many sensitive components. With the help of these components, tactile sensors can measure multiple properties.
The functional components of an industrial robot's tactile sensor include a microswitch sensitive to varying ranges of motion. It's an array of touch sensors that, together, form a larger sensor called the touch sensor. Individual touch sensors interpret the physical contact between the robot's finger and the textured surface. Once the industrial robot makes contact with an object, it sends a signal to the controller.
This article primarily introduces the functions and types of tactile sensors for industrial robots. A review of the full text reveals that vision and touch are complementary modes in the human domain of industrial robot operation technology. Industry experts predict that touch sensors will soon incorporate vision technology into mainstream robot applications. Essentially, an industrial robot tactile sensor is a touch sensor that can provide information related to the object being touched. The transmitted information is about the shape, size, and type of the touched object.
