An AGV controller can look perfectly suitable on a datasheet and still cause problems when the vehicle reaches the commissioning stage.
The reason is often simple: the controller was selected by processor, I/O count, or communication ports before the chassis architecture was fully considered.
A differential-drive AMR, a single-steering-wheel AGV, and a four-steering-wheel heavy-duty vehicle do not ask the controller to do the same job. The number of motors, steering axes, encoders, feedback signals, and synchronization requirements can be very different.
So before choosing an AGV controller, start with one question: How does the vehicle need to move?
Start With Your AGV Drive Architecture
The drive configuration determines much of the motion-control workload.
A differential-drive vehicle mainly controls the speed difference between two powered wheels. A steering-drive vehicle must control both traction speed and steering angle. Once several steering units are used together, synchronization becomes increasingly important.
HKT ROBOT's current controller range is designed around mainstream mobile robot chassis configurations including differential drive, steering wheel, and omni-wheel systems.
| Drive System | Main Controller Task | Typical Control Complexity |
| Differential Drive | Coordinate Left And Right Wheel Speed | Low To Medium |
| Single Steering Wheel | Control Traction And Steering Angle | Medium |
| Dual Steering Wheel | Synchronize Two Traction And Two Steering Axes | Medium To High |
| Four Steering Wheels | Coordinate Multiple Drive And Steering Axes | High |
| Omni / Mecanum Drive | Independently Coordinate Multiple Wheel Speeds | High |
The point is not that one system is better than another.
The right AGV controller is the one that matches the motion your vehicle actually needs.
AGV Controller for Differential Drive Systems
A differential-drive AGV normally uses two powered wheels positioned on opposite sides of the chassis, together with passive support wheels or casters.
When both wheels rotate at the same speed, the vehicle travels straight. Changing the speed difference makes it turn, while opposite wheel directions allow the chassis to rotate in place. Standard differential drive does not provide true lateral movement.
This makes the control logic relatively straightforward, but several details still matter.
The controller needs reliable speed feedback from both drive motors. Wheel diameter, gear ratio, encoder feedback, acceleration settings, and left-right motor matching all affect how well the vehicle maintains its heading.
For a typical differential-drive project, check:
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Number of traction axes
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Motor voltage and power
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Encoder interface
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Wheel diameter and gear ratio
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CAN / CANopen or other communication protocol
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Required I/O for sensors and safety devices
Dual-channel motor control is commonly used in differential mobile robots because both motors can be coordinated together rather than treated as completely independent systems. Roboteq, for example, uses this architecture specifically for differential mobile robots.
Best fit: warehouse AMRs, delivery robots, light-duty transport AGVs, and vehicles that need compact turning but not sideways movement.
AGV Controller for Single Steering Wheel Systems
A steering drive is different.
The module usually combines a drive motor, steering motor, gearbox, wheel, and steering-angle feedback. Instead of controlling wheel speed only, the AGV motion controller must coordinate both:
Traction Speed + Steering Angle
HKT ROBOT's steering-drive architecture follows this principle: the controller adjusts wheel speed and steering angle according to vehicle speed and required direction.
For a single-steering-wheel AGV with passive casters, the controller usually manages at least one traction axis and one steering axis.
That means steering feedback becomes important.
The controller needs to know not only how fast the wheel is rotating, but also where it is pointing. Depending on the system, this can involve an absolute steering encoder, incremental encoder with homing, or another angle-feedback method.
A controller that works well on a two-wheel differential platform is therefore not automatically the right choice for a steering-drive chassis.
Best fit: compact transport AGVs, tugger AGVs, and vehicles that need conventional forward, reverse, and steering movement.
Dual Steering Wheel AGVs Need Better Synchronization
Using two steering drive wheels increases traction and gives the chassis more flexibility, but it also increases the control workload.
Instead of one steering angle and one traction speed, the controller may now need to coordinate:
2 Traction Axes + 2 Steering Axes
The steering units cannot simply point in approximately the same direction.
Their steering angles, speed commands, zero positions, and vehicle geometry must work together. Errors caused by steering zero offset, gearbox backlash, installation accuracy, tire deformation, or poor synchronization can affect path tracking and docking performance.
For this type of project, check whether the AGV vehicle controller can handle:
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Multiple servo axes
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Steering-angle feedback
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Coordinated motion
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Encoder calibration
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Vehicle geometry parameters
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Fast and stable communication with the servo drives
This architecture is often more suitable when the vehicle carries a higher load or needs more flexible positioning than a basic differential-drive platform.
Four-Steering-Wheel AGVs Need More Than More I/O
Four steering drives can give an AGV excellent maneuverability.
With the correct chassis and control strategy, multi-steering-wheel systems can support movements such as forward travel, rotation, diagonal movement, and lateral repositioning. HKT's steering-drive guidance notes that coordinated three- or four-wheel layouts can support lateral and sideways movement while maintaining chassis orientation.
But this flexibility comes with additional control complexity.
A four-steering-wheel platform can involve multiple traction and steering axes that must be coordinated continuously. The controller therefore needs sufficient motion-control capability, communication bandwidth, feedback processing, and software support.
This is why simply asking: How many I/O ports does the controller have? is not enough.
A better question is that Can the controller coordinate my complete steering and drive architecture?
For heavy-duty or multidirectional AGVs, the controller, servo drives, motors, encoders, gearboxes, and steering units should ideally be reviewed as one motion system rather than selected separately.
What About Omni-Wheel and Mecanum AGVs?
Omnidirectional vehicles create another control challenge.
Instead of physically rotating a steering module, the controller creates vehicle motion by changing the direction and speed of several independently driven wheels.
For example, a four-wheel Mecanum system typically requires independent control of four motors. Roboteq demonstrates this architecture using four motor channels coordinated over a CAN network.
The AMR controller therefore needs to convert the required vehicle motion into the correct wheel-speed commands.
These systems are attractive when the vehicle must:
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Move sideways
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Make diagonal corrections
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Reposition without changing orientation
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Work in restricted spaces
But wheel-speed synchronization, chassis dimensions, encoder feedback, and floor conditions all affect actual movement.
Communication Compatibility Matters
Once the drive architecture is clear, check how the controller communicates with the servo drives and other components.
Common interfaces in mobile robot systems include:
CAN / CANopen, EtherCAT, RS485, Modbus, and Ethernet.
HKT ROBOT's existing controller guide identifies CAN bus, CANopen, EtherCAT, and other industrial interfaces as part of AGV controller integration with drives and vehicle systems.
But there is an important detail:
Having a CAN port does not automatically mean two devices are compatible.
The controller and servo drive still need to support the same communication protocol, object definitions, commands, feedback data, and operating modes.
This is why it is useful to confirm the exact servo-drive model before finalizing the AGV control system.
The same logic applies to encoders.
Incremental encoders, absolute encoders, steering-angle sensors, and other feedback devices must all match the controller and drive architecture.
Do Not Forget Safety and I/O
Motion is only part of the controller's job.
The vehicle may also need to exchange signals with:
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Safety laser scanners
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Emergency stop circuits
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Bumpers
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Limit switches
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Lifting modules
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Cargo sensors
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Charging systems
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Navigation sensors
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PLCs or upper-level systems
One practical mistake is selecting a controller with only enough I/O for the first prototype.
The vehicle may later add sensors, automatic charging, lifting functions, or additional safety devices. Leaving some expansion capacity can make later development much easier.
What Information Should You Prepare Before Selecting an AGV Controller?
You do not need a finished vehicle before discussing the controller.
A basic chassis concept is usually enough to start.
Send your supplier:
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Vehicle type and application
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Total vehicle weight and payload
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Chassis layout
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Number of drive motors
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Number of steering motors
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Motor voltage and rated power
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Encoder type
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Wheel diameter and gear ratio
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Communication protocol
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Navigation method
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Required lifting or auxiliary axes
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Safety and I/O requirements
A chassis drawing or simple layout is especially useful.
It allows the controller supplier to understand the complete motion architecture instead of recommending hardware based only on one motor specification.
Building the AGV Drive System With HKT ROBOT
Choosing an AGV controller becomes easier when the controller and drivetrain are considered together.
HKT ROBOT provides components for different AGV and AMR chassis configurations, including steering drive wheels, differential drive wheel units, servo motors, servo drives, gearboxes, controllers, and lifting modules. The current HKT controller offering supports mainstream configurations including differential drive, steering-wheel, and omni-wheel platforms.
This allows our engineering team to look beyond the controller itself.
For a new project, we can review the vehicle layout, payload, movement requirements, motor configuration, encoder feedback, communication interface, and installation space, then help match the motion components around the chassis.
If you are developing a new AGV or AMR, send us your chassis layout, load, motor requirements, and required movement.
We can help you evaluate the controller, servo drive, motor, and drive wheel as one system before you move further into vehicle development.
Send Your AGV Chassis Layout For A Drive System Review.
AGV Controller FAQs
Can One AGV Controller Work With Different Drive Systems?
Yes, if the controller hardware and software support the required chassis architecture. Differential drive, steering drive, and omnidirectional systems require different motion algorithms, motor channels, and feedback handling, so compatibility should be confirmed before selection.
Does an AGV Controller Replace the Servo Drive?
Usually no. The AGV controller calculates vehicle motion and sends commands, while the servo drive controls the motor's torque, speed, or position based on those commands. The two components need compatible communication and feedback interfaces.
Which Communication Protocol Is Best for an AGV Controller?
There is no single best protocol for every AGV. CANopen is widely used in mobile robot drive systems, while EtherCAT can be useful when faster synchronized multi-axis communication is required. The correct choice depends on the controller, servo drives, axis count, and vehicle architecture.
What Is the Best Controller for a Differential Drive AGV?
Look for a controller that can coordinate both traction motors, process encoder feedback, communicate reliably with the servo drives, and integrate the vehicle's navigation and safety signals. Motor and wheel parameters should also be configurable for the actual chassis.
What Is the Best Controller for a Steering Wheel AGV?
A steering-wheel AGV needs both traction and steering control. The controller should therefore support the required number of servo axes, steering-angle feedback, encoder calibration, communication interfaces, and coordinated vehicle motion.
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