AGV (Automated Guided Vehicle) charging is one of the factors that has the greatest impact on the efficiency of an industrial automation system. In recent years, charging technologies have evolved from traditional contact-bar stations to modern wireless charging systems, capable of completely eliminating physical connections between the charger and the vehicle. In this article, we analyse how each technology works, its advantages and when it makes sense to adopt a fully wireless solution.
The use of AGVs (Automated Guided Vehicles) and AMRs (Autonomous Mobile Robots) is continuously growing across logistics, industrial manufacturing and automation. With increasingly large fleets operating 24/7, charging technology has also had to evolve to ensure greater reliability, lower maintenance requirements and simpler infrastructure management.
In recent years, three major stages of evolution have emerged: from traditional contact-based charging stations, to solutions featuring wireless communication, and finally to modern fully wireless systems that eliminate any physical connection between the vehicle and the charging station.
What is AGV charging?
AGV charging is the process through which the vehicle’s battery is supplied with energy during operational stops or at scheduled points within the work cycle. Depending on the technology used, energy can be transferred through electrical contacts or via wireless systems based on electromagnetic induction.
First generation: power bars and communication bars
For many years, the most widespread solution was based on contact bars.
When the AGV reached the charging station, it came into contact with two separate systems:
- power bars, used to transfer energy;
- communication bars, used to carry the CAN bus between the battery charger and the Battery Management System (BMS).
Through the CAN bus, the BMS communicated with the charger, transmitting all the information required for charging: requested voltage, maximum permitted current, battery status, any alarms and operating conditions.
This solution was simple, reliable and widely proven. However, it also presented several limitations caused by the presence of electrical contacts:
- mechanical wear of the bars;
- need for periodic maintenance;
- accumulation of dirt and oxidation;
- high positioning accuracy required from the AGV;
- possibility of electrical arcing during contact, particularly when high currents are involved.
As AGV fleets and the number of daily charging cycles increased, these issues became increasingly significant.
Second generation: the CAN bus becomes wireless
To eliminate at least some of the electrical contacts, many manufacturers began replacing communication bars with wireless systems.
One of the most widely adopted solutions uses wireless CAN gateways, such as those manufactured by IFM, which convert CAN traffic into radio communication (Bluetooth or other wireless technologies) while keeping the protocol used by the BMS and charger completely transparent.
From a software perspective, nothing changes: the charger continues to operate as if it were connected to a standard CAN bus.
The advantages are immediate:
- elimination of dedicated signal bars;
- reduced maintenance;
- greater communication reliability;
- simplified wiring.
However, power bars are still required to transfer energy to the battery.
How does fully wireless AGV charging work?
As the system expands and multiple charging stations are installed, new challenges emerge.
Wireless communications use a limited number of radio channels. When several stations are located within the same area, it therefore becomes necessary to prevent an AGV from accidentally connecting to the gateway of the wrong charging station.
For this reason, a supervisory system is generally introduced to:
- identify the charging station assigned to the vehicle;
- select the correct wireless gateway;
- enable only that specific communication.
In practice, an additional device must be installed to select the correct gateway before the charging process begins.
This architecture works effectively, but increases system complexity, requires additional configuration and makes the management of large AGV fleets more demanding.
Third generation: fully wireless energy and communication
The next stage of evolution is the complete elimination of physical connections.
In the latest-generation inductive charging systems, both energy transfer and communication between the charger and the BMS take place entirely wirelessly.
There are no longer:
- power bars;
- dedicated signal bars;
- external CAN gateways;
- devices for selecting the charging station.
When the vehicle reaches the correct position, the system automatically establishes communication and begins transferring energy without any mechanical contact.
The advantages are significant:
- elimination of contact wear;
- no problems caused by oxidation or dirt;
- elimination of the risk of electrical arcing;
- lower maintenance requirements;
- greater long-term reliability;
- simpler and more easily scalable installations.
For facilities with large AGV fleets and numerous daily charging cycles, this is currently the most technologically advanced solution.
The Archimede Energia platform
The evolution of charging technologies does not, however, mean that every system can immediately be converted to wireless charging.
Many manufacturers need to manage a transition phase in which traditional charging stations coexist with new wireless stations.
For this reason, Archimede Energia’s Battery Management System has been designed as an open platform, independent of the technology used for energy transfer.
The BMS is currently compatible with the main wireless charging technologies available on the market, including:
- ENRX
- Delta
- Wiferion
- Multipower
The software architecture makes it possible to manage the protocols required by different manufacturers while maintaining a consistent interface with the Battery Management System and the vehicle.
A new feature: dual charging technology on the same AGV
The latest software release introduces a feature that is particularly valuable for manufacturers and system integrators: the ability to install both traditional contact-based charging and wireless charging on the same AGV.
The two charging modes operate in mutual exclusion: the system automatically detects which technology is available and enables only that option, preventing any potential conflict.
This solution provides several advantages:
- gradual migration towards wireless charging;
- ability to use either traditional or wireless charging stations;
- greater vehicle operational availability;
- reduced infrastructure upgrade costs;
- development of a single hardware and software platform for different configurations.
For OEMs designing new AGV platforms or upgrading existing fleets, choosing a BMS that is compatible with multiple charging technologies means protecting the investment over the long term. The ability to manage both contact-based and wireless charging systems makes it possible to transition towards inductive charging without having to redesign the vehicle’s onboard electronics.
Conclusions
AGV charging has followed a clear technological evolution. The industry has moved from fully wired solutions to systems featuring wireless communication, and today to platforms in which both energy and data are transferred without any physical contact.
In addition to improving reliability and reducing maintenance requirements, these technologies simplify the infrastructure and make it possible to create safer charging areas, without contacts subject to wear and without the risk of electrical arcing.
Thanks to an open platform that is compatible with the main wireless technologies available on the market and capable of managing traditional and wireless charging simultaneously in mutual exclusion, Archimede Energia provides OEMs with a flexible solution designed to support the transition towards the new generation of AGVs and AMRs.
Would you like more information?
The Archimede Energia team will be happy to answer all your questions.
