Autonomous navigation is one of the prerequisites for robots to achieve intelligence, and is a key factor that gives robots the ability to sense and act. If the robot does not self-locate navigation, can not analyze, judge and select the surrounding environment, and plan the path, then there is still a big gap between this robot and intelligence. Then, in the existing SLAM technology, what are the commonly used positioning navigation technologies for robots?
Visual positioning navigation
Visual positioning navigation is mainly done by means of visual sensors. The robot acquires images by means of monocular, binocular cameras, depth cameras, video signal digitizers or DSP-based fast signal processors, and then optically processes the surrounding environment. The acquired image information is compressed and fed back to a learning subsystem composed of a neural network and a statistical method, and then the subsystem associates the acquired image information with the actual position of the robot to complete the positioning.
advantage:
· Wide range of applications, mainly used in the fields of drones , surgical instruments, transportation, agricultural production, etc.
Disadvantages:
· The amount of image processing is huge, and the general computer cannot complete the calculation, and the real-time performance is poor;
· Limited by lighting conditions, unable to work in dark environments;
Ultrasonic positioning navigation
The working principle of ultrasonic positioning and navigation is that the ultrasonic sensor emits an ultrasonic wave emitted from the probe, and the ultrasonic wave encounters an obstacle in the medium and returns to the receiving device. By receiving the ultrasonic reflection signal emitted by itself, and calculating the propagation distance S according to the ultrasonic transmission and echo receiving time difference and propagation speed, the distance from the obstacle to the robot can be obtained, that is, there is a formula: S=Tv/2 where T - time difference between ultrasonic transmission and reception; v - wave velocity of ultrasonic waves propagating in the medium.
advantage:
· low cost;
· It can identify objects that cannot be recognized by infrared sensors, such as glass, mirrors, black bodies and other obstacles;
Disadvantages:
· It is susceptible to weather, surrounding environment (specular reflection or limited beam angle), as well as obstacles, rough surfaces and other external environments;
· Since the propagation distance of ultrasonic waves in the air is relatively short, the application range is small and the ranging distance is short.
· Slow acquisition speed and poor navigation accuracy;
Infrared positioning navigation
The principle of infrared positioning navigation is that the infrared IR sign emits modulated infrared rays, which are received by an optical sensor installed indoors for positioning.
advantage:
· Long-distance measurement, which can measure long distances without reflectors and low reflectivity;
· With synchronous input, multiple sensors can measure simultaneously;
· Wide measuring range and short response time;
Disadvantages:
· The minimum distance detected is too large;
· The infrared range finder is subject to large interference from the environment. It is impossible to detect the distance for objects that are similar to black and transparent, and is only suitable for short-distance propagation;
· When there are other obstructions, it is not working properly. It is necessary to install receiving antennas in each room and corridor, and lay rails, which is relatively expensive;
Silicon Controlled Rectifier (SCR)
Silicon Controlled Rectifier (SCR) is short for silicon controlled rectifier. SCRs are available in one-way, two-way, turn-off, and light control types. It has the advantages of small size, light weight, high efficiency, long life, easy control, etc. It is widely used in occasions such as controllable rectification, voltage regulation, inverter, and non-contact switches and other automatic control and high-power electric energy conversion.
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YANGZHOU POSITIONING TECH CO., LTD. , https://www.cnchipmicro.com