Why Low-Voltage Motion Control Is Growing

Automated guided vehicles and autonomous mobile robots are becoming important parts of modern intralogistics systems.

These machines transport materials, deliver components, and support warehouse operations without requiring fixed conveyor routes.

Unlike many stationary industrial machines, mobile robots depend on onboard battery systems. Their motion control architecture must therefore balance electrical efficiency, compact installation, operating time, and safety.

Low-voltage systems using 24 V or 48 V battery supplies are common design options for mobile equipment.

1. Understand the Main Drive Axes

A mobile robot may contain several independently controlled motion axes.

• Traction: Provides forward and reverse movement.
• Steering: Controls wheel direction where the vehicle design requires it.
• Lifting: Operates forks, platforms, or lifting mechanisms.
• Auxiliary motion: Supports doors, conveyors, or additional mechanisms.

Each axis has different torque, speed, duty-cycle, and feedback requirements.

Engineers should calculate the actual mechanical load before selecting motors and drives.

2. Match the Drive to the Battery System

Battery voltage affects drive selection, current requirements, cable sizing, and power distribution.

For the same electrical power, a lower supply voltage generally requires higher current. This makes conductor resistance, voltage drop, connector ratings, and thermal management important design considerations, similar to power distribution checks performed for an Allen-Bradley PowerFlex drive circuit board.

Check the battery's operating voltage range rather than using its nominal voltage alone. Charging conditions and battery state can change the available voltage.

The drive must support the required operating range and the expected peak current.

3. Consider Regenerative Energy

During deceleration, some motor drive systems can return energy to the DC supply or battery.

Regenerative operation may improve energy utilization, particularly when a vehicle performs frequent acceleration and braking cycles.

However, the battery and power architecture must be capable of accepting the returned energy.

Engineers should review battery charging limits, DC bus behavior, braking requirements, and the drive manufacturer's regeneration specifications.

4. Integrate Motion Feedback and Safety

Mobile robots rely on accurate motor feedback to control speed, position, and steering.

Depending on the application, feedback devices may provide incremental or absolute position information.

Safety functions may also require monitored speed, safe torque removal, or other validated protective functions supervised by a dedicated industrial safety controller.

Some integrated mobile drive solutions support industrial safety communication and safety-rated feedback, pairing with dedicated precision controllers such as an Ovation servo driver module. The complete system still requires application-specific safety engineering and validation.

5. Coordinate Drives With the Vehicle Controller

The vehicle controller coordinates drive commands with navigation, obstacle detection, battery monitoring, and machine status, frequently running through a compact system master such as an Allen-Bradley CompactLogix controller.

Industrial communication networks can exchange speed references, operating modes, diagnostic information, and drive status over dedicated fieldbus interfaces such as an ABB drive link board.

Engineers should define how the vehicle behaves when communication is interrupted or a drive reports a fault.

Recovery logic should prevent unexpected movement after communication returns.

6. Test Under Real Operating Conditions

Commissioning should cover more than unloaded movement.

• Test acceleration and deceleration under representative loads.
• Verify steering accuracy and turning behavior.
• Check battery voltage during peak demand.
• Evaluate regenerative operation.
• Test communication loss and drive fault handling.
• Verify emergency stopping and safety functions.

Also review cable movement, connector retention, and thermal behavior during repeated operating cycles.