AGV是自动导引运输车（Automated Guided Vehicle）的英文缩写，指装备有电磁或光学等自动导引装置，能够沿规定的导引路径行驶，具有安全保护以及各种移载功能的运输车，AGV属于轮式移动机器人（WMR――Wheeled Mobile Robot）的范畴。
AGC（Automated Guided Cart），属于AGV的一类，但由于具有独特的功能与用途，将它单独出来讲。AGC是以日本为代表的简易型AGV技术，该技术追求的是简单实用，极力让用户在最短的时间内收回投资成本。该类AGV完全结合简单的生产应用场合（单一的路径，固定的流程），AGC只是用来进行搬运，并不强调AGV的自动装卸功能。由于日本的基础工业发达，AGC生产企业能够为AGC配置上几乎简单得不能再简单的功能器件，使AGC的成本几乎降到了极限。
1. Definition of AGV and AGC
AGV is the English abbreviation of Automated Guided Vehicle, which refers to a transport vehicle equipped with automatic guidance devices such as electromagnetic or optical, which can travel along a prescribed guiding path, and has safety protection and various transfer functions. AGV belongs to the category of Wheeled Mobile Robot (WMR-Wheeled Mobile Robot).
AGC (Automated Guided Cart), belongs to a category of AGV, but because of its unique functions and uses, it will be discussed separately. AGC is a simple AGV technology represented by Japan. The technology pursues simplicity and practicality, and strives to allow users to recover their investment costs in the shortest possible time. This type of AGV is completely combined with simple production applications (single path, fixed process), AGC is only used for handling, and does not emphasize the automatic loading and unloading function of AGV. Due to the developed basic industry in Japan, AGC manufacturers can configure AGC with functional devices that are almost as simple as they can be, making the cost of AGC almost reduced to the limit.
国家标准《GB/T 20721—2006 自动导引车通用技术条件》第4.3.2 条款规定，“在自动导引车上安装与地面移载装置的连锁功能。在移载过程中任意一方的意外故障，都应通知对方，并及时处理，防止货物或设备的损坏。发生移载故障后，在排除故障之前，系统应维持停止状态”。
国家标准《GB/T 20721—2006 自动导引车通用技术条件》第4.3.3 C）条款规定，“在自动导引车与控制台间应该具有调度和控制功能”。
2. All-round comparison between AGV and AGC
(1) Different driving methods
Considering the importance of stability and reliability for AGVs used in industrial fields, AGVs are generally driven by servo motors, and the motor and the wheel train are integrated, which is expensive. However, AGC only meets the requirements of simple logistics and transportation, and is generally driven by ordinary DC motors, and the price is low.
(2) Different positioning accuracy
The AGV positioning accuracy standard is ±10mm, which can meet the requirements of docking between the conveyor on the AGV and the conveyor on the ground.
The AGC positioning accuracy standard is ±20mm, which cannot guarantee automatic and precise positioning and docking with the ground conveyor.
(3) Different speed control methods
The speed of the AGV in the straight section and the curved section is different, which can ensure that the goods carried by the AGV will not overturn due to the large centrifugal force during the curve.
The speed of the AGC is the same in straight and curved sections. If both are at high speed, it will be very dangerous when cornering. If the speed is both low, it is difficult to meet the work rhythm requirements. Generally, manufacturers install a section of angle steel on the ground of the curved section of the AGC running route to forcibly correct the running track of the wheels of the AGC when turning, otherwise the AGC will deviate from the running route.
(4) Different non-contact obstacle detection devices
The AGV uses a diffuse reflection laser sensor as a proximity obstacle detection device, which is generally imported, and the effective detection distance is 4m, which has a very good detection effect on personnel and equipment. AGC uses infrared sensor as a proximity obstacle detection device, because the detection distance of infrared sensor to different objects is determined by the reflection ability of the object (for example, the reflection ability of metal objects is higher than that of people), so it cannot guarantee to reach the calibrated detection distance (2m ), in order to ensure sufficient braking distance when an obstacle is detected, the running speed of AGC is generally low.
(5) Interlock with ground conveying equipment
Clause 4.3.2 of the national standard "GB/T 20721-2006 General Technical Conditions for Automatic Guided Vehicles" stipulates that "the interlocking function with the ground transfer device is installed on the automatic guided vehicle. In case of failure, the other party should be notified and dealt with in time to prevent damage to the goods or equipment. After a transfer failure occurs, the system should remain in a stopped state until the failure is eliminated.”
The AGV and the ground conveying equipment are interlocked by means of an infrared beam switch. When the AGV reaches the transfer position and the interlock is successful, the AGV's console and the ground conveying equipment's console communicate with each other, so that the AGV can communicate with the ground. Transfer equipment for transfer. After the transfer is completed, the AGV console communicates with the ground equipment console again to release the interlock, and the AGV can leave the transfer position to perform the next task.
Because the positioning accuracy of the AGC is not enough, it cannot be automatically transferred with the ground conveying equipment, and there is no interlocking function.
Clause 4.3.3 C) of the national standard "GB/T 20721-2006 General Technical Conditions for Automatic Guided Vehicles" stipulates that "there should be scheduling and control functions between the automatic guided vehicle and the console".
The AGV adopts the centralized control method of the central console. The current status of each AGV can be displayed in real-time animation in the central console. The central console can schedule each AGV separately, and can schedule AGVs to avoid collisions.
Although some AGC systems have a central console, they cannot schedule each AGC separately, nor can they schedule collisions between AGCs.
(7) Connection to higher-level systems
As an automatic operation device, AGV is essentially a subsystem of the customer's system. Although AGV can operate as an independent system, it must accept the customer's instructions to complete a certain work, and report the task to the customer's system after the work is completed. Done, and accept the next mission. That is to say, the AGV and the customer's system (the upper-layer system for the AGV system) must be connected to exchange data.
AGC cannot connect with the upper-layer system (all AGC instances can prove this), which is the most critical difference between AGV and AGC.
3. Under what circumstances to choose AGV & AGC
The control of AGV is more complicated, and there are special algorithms from walking posture to multi-vehicle scheduling management. The AGC is much simpler, and a PLC may do it. Due to the obvious differences in function and price, users should carefully analyze the requirements to determine the AGV or AGC before implementing the project.
Combining the technical characteristics of the two, generally when the following conditions are met at the same time, AGC can be selected.
(1) A single path. That is, there are no branches in the loop in which the AGV operates, but a single loop.
(2) Fixed process. That is, the AGV repeats the same action for each task cycle, that is, the position sequence of each cycle parking point is unchanged. For example: AGV may need to stop at three points A, B, and C in the cycle, then A, B, and C are the order of AGV parking. It is impossible for AGV to go directly from point A to point C, regardless of whether there is work at point B All parking. Of course, a fixed process refers to a preset process, and there can be multiple ones. But in any case, the process is predicted by humans and is preset, not calculated by the upper computer according to the scheduling strategy.
(3) The guidance and positioning accuracy of the AGV is not high, and the AGV only needs to transport the goods to the approximate location.
(4) No transfer mechanism is required, usually manual loading, unloading or drag-type AGC.
In addition, when there are multiple branches, multiple loops, complex paths with confluence and diversion in the running loop, changeable processes, high positioning requirements, and more complex loading and unloading tasks need to be completed , you should choose AGV.
A high-quality AGV system should have the following conditions: high-quality body structure and mechanical, electronic, and communication facilities, easy-to-operate, easy-to-configure, easy-to-expand and powerful control systems, precise positioning systems, and powerful drives system, reliable security system, it is better to have a beautiful appearance.