In the field of robotics, the chassis is the cornerstone determining its mobility and environmental adaptability. A well-designed chassis not only handles complex terrain but is also a prerequisite for precise control and advanced applications.
Taking tracked chassis as an example, an excellent tracked chassis design must adhere to three core principles: terrain adaptability, motion stability, and rich expandability. These three are interconnected and together constitute the chassis's overall performance.
Several tracked chassis with suspension systems released by Huaner have been well-received by students, engineers, and robotics enthusiasts due to their excellent performance. Today, we will take Huaner's Raptor tracked chassis as an example to deeply analyze the key design points of an excellent tracked chassis from both academic and engineering practice perspectives.
High-Elasticity Torsion Spring Suspension System When a chassis faces wheel suspension or uneven ground pressure, it will lose traction and stability. Raptor's innovation lies in its patented design-the high-elasticity torsion spring suspension system. The core of this system is a torsion spring-swing arm mechanism based on high-elasticity carbon steel. When a road wheel encounters an obstacle and is lifted, the swing arm forces the torsion spring to elastically deform. This process brings three core advantages:
Passive Adaptation: The system passively ensures all road wheels are in contact with the ground as simultaneously as possible, increasing the contact area and improving stability, without the need for sensors or controllers.
Energy Storage and Release: The torsion spring absorbs impact energy when compressed and rebounds smoothly when released, effectively absorbing and buffering impacts from the ground and protecting the precision sensors mounted on top, such as LiDAR, depth cameras, and the main controller.
Maintaining Traction: On rough terrain, keeping multiple wheels in contact with the ground at all times means that power can continuously and effectively act on the ground, preventing slippage and power loss due to suspension.
This design transforms the Raptor chassis from a rigid structure into a flexible system that can "sense" and "adapt" to terrain, greatly expanding its passability in rough road environments.
Differential Operation and Precise Control: The Raptor uses a classic differential drive structure. The two tracks are driven by independent high-precision encoder motors, forming a closed-loop control system. The controller can know the exact speed and angle of the motor in real time, thus compensating for abnormal situations such as slippage. Forward movement, backward movement, and turning to any radius are achieved by controlling the speed difference between the two tracks.
To prevent slippage, Raptor uses anti-slip nylon tracks with a toothed design that effectively grips the ground, providing greater traction. The meshing design of the chassis's drive wheels and tracks ensures efficient power transmission and prevents derailment. Bearing-type road wheels greatly reduce running resistance, ensuring smooth power transmission to the ground.
Empowering Advanced Applications
An excellent chassis is not only a mobile platform but also a platform for sensors and intelligence. Raptor's design fully considers this.
It can carry extension accessories such as LiDAR, depth cameras, and robotic arms. Its stable and shock-resistant characteristics provide a high-quality data acquisition foundation for LiDAR and depth cameras, which is a prerequisite for high-precision mapping and dynamic obstacle avoidance. Accurate odometer information provided by high-precision encoders and a robust chassis allows the vehicle to reduce accumulated errors and achieve closed-loop detection in SLAM mapping and navigation.
Because Raptor achieves a good balance between stability, accuracy, and adaptability, it is widely used in Huaner's robots, such as the MentorPi-T1 tracked robot and the LanderPi-T1 hybrid robot, providing a reliable and powerful mobile platform for ROS2 learning, AI application development, and high-level embodied intelligence research.
In summary, designing a good tracked chassis is a systems engineering project, far more than just assembling parts. It requires not only precise differential control and anti-slip, high-rigidity transmission components, but also a suspension system to cope with complex terrain, and deep integration with upper-level sensors and intelligent algorithms to unleash its full potential.
