Efficient, low-cost material transportation is an important measure for many manufacturing plants and warehouses to improve their operations. AGV" to achieve efficient and low-cost material transportation, and in terms of safety, AG is safer than other material transportation methods, especially compared with manual handling. One of the main advantages of AGVs is that they do not disrupt people or infrastructure. Indeed, AGVs are safer than traditional manual vehicles such as traditional forklifts
One of the things that many companies have to go through is done manually. Now, with the advent of the intelligent era, some work has been replaced by robots, which has gradually realized logistics robots, food delivery robots, etc. AGV handling robots, also known as path trolleys of unmanned trucks, can automatically move goods for storage. As the main implementation method of industrial automation logistics, they are widely used in the fields of repetitive handling, harsh moving environments and high environmental requirements.
In fact, AGVs have many safety devices to prevent accidents, such as flashing lights, sound devices, physical emergency bumpers and ultrasonic equipment. In addition, the Jiangguo National Standards Association (ANS regulations specify layout requirements, braking distances and other safety-related items to ensure safety. How to avoid AGVs colliding with each other and running on the same path? Traffic control is here. , For example, a flexible manufacturing system of multiple AGVs requires traffic control so that the AGVs do not touch each other. Traffic control can be performed locally on the AGV or by software in a fixed computer elsewhere in the factory. Local methods include area control , sensor control and integrated control. Each method has its advantages and disadvantages
(1) Regional control. Zone Control is the most enjoyable to use in most environments because it is simple to install and easy to expand. Zone control uses wireless transmitters to send signals in a fixed zone. Each AGV contains a sensing device to receive this signal and respond to the transmitter. If an area is empty, the signal is set to "empty", allowing any signal to enter and pass through the area. If there is AGV in the area, send a "stop" signal, all AGVs trying to enter the area stop and wait for their turn. Once the AGVs in the zone have been removed out of the zone, send a "null" signal to one of the waiting AGVs. Another way to establish zone control traffic management is to have each robot have its own small transmitter/receiver Each AGV will send its own "don't enter" message to all AGVs in the space area close to it. One problem with this approach is that if one area fails then all AGVs have the risk of colliding with any other AGV in the area. Control is a low-cost and effective regional AGV control method. (2) Sensor control. Sensor control is to use obstacle avoidance sensors to avoid collisions with other AGVs in the area. Sensors include: ultrasonic sensors, and the working principle of radar Similar; optical sensors, using infrared sensors; bumpers, physical contact sensors. Most AGVs are equipped with some form of bumper sensor as a failsafe. Ultrasonic sensors send out a chirp or high frequency signal output and then wait for a reply AGV to pass Judging the contours of the reply signal can tell if there is an object ahead and take the necessary action to avoid a collision. Optical sensors use an infrared transmitter/receiver, which emits an infrared signal, which is then reflected back, the same way it works as an ultrasonic sensor is a similar concept.
A comprehensive control method combining sensor control and area control is used to realize traffic control between AGV vehicles. Each AGV in the system is equipped with two infrared obstacle avoidance sensors, one is installed in the front to detect obstacles in the front, and the other is installed in the right front to detect the oncoming vehicles from the side. For the sake of safety, the system also comprehensively uses the method of area control, and the dispatch center will set up a mutually exclusive signal in the area that may collide. When an AGV enters the area, the mutual exclusion signal will be occupied. At this time, the dispatch center will send a stop signal to other AGVs trying to enter the area. When the previous vehicle leaves the area, the mutual exclusion signal will be released, and the latter vehicle will be released. car to enter the area.
