Introduction to the application and characteristics of various types of sensors
The smart sensor is a sensor with information processing function, with a microprocessor, with the ability to collect, process, and exchange information. It is a combination of sensor integration and microprocessor. Like many smart systems, smart grids are not individual individuals, but the product of many equipment and technologies. Among them, the sensor equipment in monitoring the first line is small, but it is absolutely important. In the development of smart grids, the use of traditional sensors has made it impossible to quickly and directly measure the quality and fault location of certain power products and monitor them online. The smart sensor can be used to measure directly, and measure product quality indicators and faults (such as temperature, pressure, and flow). For example, in order to meet the development needs of smart grids, China has introduced a fiber-optic current sensing system, which realizes the full digital closed-loop control of the pipeline current sensing system. It has the characteristics of stability, linearity and sensitivity, and meets a large range of high range. Precision measurement requirements. At present, smart sensors have become the hotspot and frontier of sensor research in the world. Vigorously developing smart sensor research, the leap-forward development ideas should be the key measures to occupy the commanding heights of information technology in the future.
Vision sensors are divided into two-dimensional vision sensors and three-dimensional vision sensors. Two-dimensional vision is basically a camera that can perform a variety of tasks. From detecting moving objects to positioning parts on conveyor belts, etc. Two-dimensional vision has been on the market for a long time and has taken a certain share. Many smart cameras can detect parts and assist the robot in determining the position of the part. Compared to 2D vision, 3D vision is a technology that has only recently emerged. The 3D vision system must have two different angles of the camera or use a laser scanner. In this way, the third dimension of the object is detected. Similarly, there are many applications that use 3D vision technology. For example, parts pick and place, use 3D vision technology to detect objects and create 3D images, analyze and select the best picking method.
The force/torque sensor gives the robot a sense of touch. The robot uses the force/torque sensor to sense the force of the end effector. In most cases, the force/torque sensor is located between the robot and the fixture so that all the forces fed back to the fixture are monitored by the robot. With force/torque sensors, applications such as assembly, manual guidance, teaching, and force limiting can be achieved. This type of sensor comes in a variety of different forms. The main application of these sensors is to provide a safe working environment for workers, and it is most necessary for collaborative robots to use them. Some sensors can be some kind of tactile recognition system that senses pressure through a soft surface and, if pressure is sensed, sends a signal to the robot to limit or stop the movement of the robot.
Some sensors can also be built directly into the robot. Some companies use accelerometer feedback, while others use current feedback. In both cases, when the robot senses an abnormal force, an emergency stop is triggered to ensure safety. But before the robot stops, you will still be hit by it. Therefore, the safest environment is an environment with no risk of collision. This is the mission of the next sensor. In order for industrial robots to collaborate with people, first find a way to ensure the safety of workers. These sensors come in a variety of forms, from camera to laser, for one purpose, to tell the situation around the robot. Some safety systems can be set up so that when someone appears in a particular area/space, the robot will automatically slow down and the robot will stop working if the person continues to approach.
In the part picking application, it is impossible to know if the robot gripper has correctly grabbed the part. The part inspection application gives you feedback on the position of the gripper. For example, if the gripper misses a part, the system detects the error and repeats the operation once to ensure that the part is properly captured. There are many sensors on the market that are suitable for different applications. Such as weld tracking sensors. Touch sensors are also becoming more and more popular. Sensors of this type are typically mounted on the gripper to detect and feel what the object being grasped is. The Bonner sensor is usually able to detect the velocity and derive the velocity distribution to know the exact location of the object, allowing you to control the position of the grip and the grip of the end effector. There are also some tactile sensors that can detect changes in heat.
The so-called dynamic characteristic refers to the characteristic of the output of the sensor when the input changes. In practice, the dynamic characteristics of a sensor are often expressed in terms of its response to certain standard input signals. This is because the sensor's response to a standard input signal is easily experimentally determined, and its relationship to the standard input signal has a certain relationship with its response to any input signal, and it is often known that the former can presume the latter. The most common standard input signals are step signals and sinusoidal signals, so the dynamic characteristics of the sensor are also commonly expressed by step response and frequency response.
Resolution is the ability of a sensor to sense the smallest change being measured. That is, if the input varies slowly from some non-zero value. When the input change value does not exceed a certain value, the output of the sensor does not change, that is, the change of the sensor's input quantity is inseparable. The output changes only when the input changes more than the resolution. Sensitivity refers to the ratio of the change in output Δy to the change in input Δx of the sensor under steady-state operating conditions. It is the slope of the output-input characteristic curve. Sensitivity S is a constant if there is a linear relationship between the output and the input of the sensor. Otherwise, it will change as the amount of input changes. When the output of the sensor and the amount of input are the same, the sensitivity can be understood as a magnification.