What are the charging methods for AGV cars? How to distinguish it?

With the continuous improvement and maturity of automation and technology, AGV cars are widely used in e-commerce warehousing, manufacturing, and terminals due to their efficient material handling and "goods to people" sorting characteristics. But as a highly automated and intelligent transportation equipment, AGV needs to be powered by electricity, and without the supply of electricity, it cannot work either. So, how are the commonly used charging methods for AGV cars classified and distinguished in practical applications?

1、 According to charging time, it can be divided into random charging and full cycle charging

1. Random charging

It refers to the ability to charge the AGV car at any time without time limit at each parking station. If there are more charging points to ensure that the loss of electricity during the operation of the AGV car can be replenished in a timely manner, thus achieving shallow charging and discharging of the battery, extending the service life of the car battery, and reducing the required battery capacity.

2. Full cycle charging

It refers to requiring the AGV car to exit service and enter the user designated charging area for charging, when the battery charge drops to the specified range for charging. Of course, there are also charging modes on the market that combine the above two methods.

2、 According to the charging area, it can be divided into online charging and offline charging

1. Online charging

It refers to the fact that the AGV car does not need to leave the working line or charge at a specific time. You only need to use the short time during the working process to perform charging mode. Reasonably utilizing the fragmentation time of the AGV car without occupying its working time, this method is also an extension of random charging. Embed the charging station into the workflow of the AGV car to further improve the efficiency of the AGV car.

2. Offline charging

It refers to the AGV car driving into the charging area or a dedicated charging station for charging mode after exiting service.

3、 If classified into manual mode, battery change mode, and automatic charging according to the operating method

1. Manual charging mode

The characteristics of AGV cars in manual charging mode are very safe and reliable, as well as being simple and easy to operate with low equipment costs. It can usually be used in situations where the level of automation is not particularly high and there are fewer cars and more people in the standard working system. And to ensure the endurance of the AGV car, it is necessary to equip it with large capacity batteries. Therefore, it is not possible to achieve 24-hour continuous operation of the AGV trolley.

2. Battery mode

Replacing the battery for charging is when the power of the AGV car is insufficient, and the corresponding dedicated personnel manually replace the battery pack; Put the AGV trolley into use. The replaced battery will be used after charging. Its main characteristics are simplicity, speed, and the ability to achieve 24-hour continuous operation of the AGV car throughout the day. However, it requires twice the number of battery packs, which is costly and primitive. Usually, there is a high requirement for timely response to work, but both methods require dedicated personnel to take care of them, which not only wastes manpower but also reduces the level of automation. Once the charging is missed, it will cause the AGV car to fail to work.

3. Automatic charging

Automatic charging is the automatic report and request for charging when the AGV car needs to replenish power. It is commanded by the ground control center to drive to the designated charging area, and the onboard charging connector and ground charging system are automatically connected to implement charging. After the charging is completed, the AGV car will automatically detach from the charging system and then drive towards the work area for normal operation. This type of AGV car is suitable for situations where there are many cars with few people, long work cycles, and high levels of automation.

4、 According to the electrical connection method of the charger, it can be divided into contact charging and wireless charging

1. Contact charging

Contact charging is a charging circuit that requires charging contacts and cables to connect the vehicle and power supply system. The contact charging mode can provide a large charging current to achieve fast charging. This is also a way that people choose more. However, this method is not suitable for frequent random charging, as there may be wear on the charging contacts, so regular replacement is necessary. Moreover, there may be a fire during the charging process, which poses a safety hazard. In addition, as the charging contact is an exposed component, it cannot operate normally in humid, low-temperature condensation, flammable and explosive environments.

2. Wireless charging

Wireless charging refers to a non-contact charging device that does not require the use of cables. It only needs to connect the vehicle and power supply system, discard the charging contacts, and ensure that no conductive contacts are exposed in the electrical device and charger. The technology of wireless charging enables electrical isolation between the charging end and the energy storage system of the AGV car, fundamentally eliminating the drawbacks caused by the plug-in charging method. Therefore, it is more comprehensive and has wider applicability.

Currently, the charging method used in the mobile robot industry is mainly automatic charging, with conductive charging devices as the main charging devices, accounting for over 90% of the market. According to data from the CMR Industry Alliance and statistics from the New Strategy Mobile Robot Industry Research Institute, approximately 17500 sets of conductive charging devices were shipped in the AGV/AMR industry in 2022, with a market size of approximately 125 million yuan.

Conductive charging, also known as contact charging, requires all charging circuits to connect the vehicle to the power system through cables and charging contacts, allowing for direct charging. There are also two types of contact charging, one is the traditional brush plate brush block type, and the other is the pin type. The former is mostly used for heavy-duty and forklifts AGVs, while the pin type is commonly seen in Kiva type storage AGVs.

In the future, charging technology will develop in three directions: standardization of charging interfaces, charging components, fast charging technology, multidimensional secure interconnection, and data exchange.