The impact of the wheel system on the maneuverability of AGV vehicles is primarily reflected in the following aspects:
1. Ability to Traverse Complex Terrain
The design of the wheel system, including the AGV drive wheel and AGV steering drive wheel configurations, directly affects the AGV vehicle's ability to pass over uneven surfaces. For example, AGVs with a four-AGV steering drive wheel layout can achieve omnidirectional movement, improving flexibility. However, if the design is not optimal, the AGV drive wheels may become suspended when passing over sunken surfaces, leading to insufficient driving force or slippage. On raised surfaces, the load on the AGV drive wheels may increase sharply, causing the current to exceed alarm thresholds and triggering operational faults.
2. Stability and Balance
The layout and structure of the wheel system, whether it involves AGV drive wheels or AGV steering drive wheels, are crucial to the stability and balance of AGV vehicles. A well-designed wheel system ensures the AGV vehicle remains stable during operation, preventing tipping or loss of control due to uneven surfaces or sharp turns.
3. Steering Flexibility
The configuration of the wheel system also affects the steering flexibility of AGV vehicles. For instance, a four-AGV steering drive wheel AGV can drive in multiple directions-longitudinal, lateral, or rotational-making it suitable for flexible operations in confined spaces. A two-AGV steering drive wheel AGV has near-comparable steering flexibility to a four-AGV steering drive wheel design, but under certain conditions, the resistance encountered by universal wheels during lateral or in-place rotation is more pronounced than that of four-steering or two-steering plus two-active-steering drive wheel AGVs, which can sometimes be significant. The single-AGV steering drive wheel layout, due to the phenomenon of inner wheel difference, has the poorest maneuverability on flat surfaces.
Steering Maneuverability
Next, let's discuss how different wheel system layouts, including AGV drive wheels and AGV steering drive wheels, affect steering maneuverability. (Maneuverability on complex surfaces will be analyzed when discussing the suspension system.)
As shown in the diagram below, a single-AGV steering drive wheel layout allows the AGV vehicle to move forward, backward, and turn left or right/correct its course. The diagrams illustrate the turning capabilities of a single-AGV steering drive wheel AGV vehicle. From the first to the fourth diagram, the turning radius progressively decreases. However, due to interference from the ground and other factors, the smallest turning radius shown in the fourth diagram may result in an uncontrollable state. Therefore, the turning radius of the AGV vehicle is generally evaluated based on the third diagram.
Although we previously mentioned that the operational stability of a two-AGV steering drive wheel AGV is not as good as that of a four-AGV steering drive wheel system, in most situations, it can maintain the same operational trajectory. As illustrated below, a two-AGV steering drive wheel AGV vehicle can not only move forward and backward but also move laterally and rotate in place. During an in-place turn, the wheelbase becomes the turning diameter of the AGV vehicle.
Let's now illustrate the operational trajectories of single- and two-AGV steering drive wheel AGVs when making a right-angle turn. Since a single-AGV steering drive wheel AGV only has one driving wheel, during a right-angle turn, the rear wheels of the AGV must be pulled past the right angle to ensure the vehicle body does not collide with the corner, as shown in the diagram below.
Now, let's look at the situation with a two-AGV steering drive wheel AGV when making a right-angle turn. As shown below, since it has both front and rear AGV steering drive wheels, the AGV vehicle can smoothly make the right-angle turn as soon as the midpoint of its driving wheels passes the corner. Therefore, with the same vehicle body size, the front clearance of a single-AGV steering drive wheel AGV must be larger than that of a two-AGV steering drive wheel AGV. In other words, compared to a single-AGV steering drive wheel AGV, the two-AGV steering drive wheel AGV has better maneuverability.
Conclusion
In summary, the selection and design of the wheel system, particularly the configuration and layout of AGV drive wheels and AGV steering drive wheels, significantly impact the maneuverability of AGV vehicles. A well-planned wheel system layout and structure can improve the vehicle's flexibility, stability, and ability to traverse complex surfaces. In practical applications, it's crucial to select the appropriate wheel system configuration based on the specific working environment and task requirements.
