AGV/AMR Design Calculator: Key Points from Parameter Calculations to Selection Guidelines

In the automated logistics sector, especially in automotive manufacturing, Automated Guided Vehicles (AGVs) play a crucial role. They efficiently transport parts and finished products within the workshop, enhancing production efficiency and logistic accuracy. Today, based on an AGV design calculator document, we will explore the key considerations in AGV design.

1. Basic Parameter Setting of AGV: The Foundation

Vehicle Attributes
The basic parameters of an AGV form the foundation of its design. Parameters such as the number of drive wheels, wheel diameter, weight, and payload capacity are interconnected and collectively determine the AGV’s overall performance. For example, an AGV with two drive wheels, a 353mm diameter, a weight of 2000kg, and a payload capacity of 15000kg indicates that it is designed for heavy-duty transportation. A higher payload capacity requires a stable structure and sufficient power support, and the choice of the number and diameter of drive wheels must ensure stability and flexibility when carrying heavy loads.

Operating Performance Parameters
Operating speed, acceleration time, and braking time are critical performance parameters. The speed is set at 0.6m/s, acceleration time at 5s, and deceleration time at 0.5s. These settings strike a balance between speed, safety, and load stability. Slower acceleration helps avoid displacement or dropping of the goods due to inertia, while shorter deceleration time enables quick stopping in emergencies, ensuring the safety of personnel and equipment.

2. Resistance Calculation in Complex Operating Conditions

Resistance Analysis under Different Conditions
AGVs encounter various types of resistance during operation, including rolling resistance, startup resistance, braking resistance, and climbing resistance. For example, under full load, rolling resistance is 3335.4N, which results from the rolling friction between the AGV and the floor, and is proportional to the vehicle’s weight and rolling friction coefficient. Startup resistance is 2040.0N, which is the force required to overcome inertia when the vehicle starts from rest. Braking resistance reaches 20400.0N to quickly stop the high-speed AGV. Additionally, when the AGV needs to climb a slope, it faces climbing resistance, which, at a 2° incline, amounts to 5820.1897N. Accurately calculating these resistances is essential for subsequent power system design and motor selection.

Influence of Surface Material and Friction Coefficient
The selection of surface materials directly affects the friction coefficient, which in turn impacts the AGV’s resistance. Common surface material combinations include polyurethane-epoxy floor, polyurethane-cement floor, rubber-epoxy floor, and rubber-cement floor, with corresponding static friction coefficients of 0.6, 0.7, 0.8, and 0.9. Different friction coefficients produce varying effects under different conditions like startup, braking, and climbing. For example, during emergency braking, a sufficiently high static friction is needed to prevent the AGV from bouncing. Therefore, the choice of floor and wheel materials should consider the required friction for various conditions.

3. Key Considerations for Motor Selection

Torque and Power Matching
Motor selection is a key aspect of AGV design, focusing on the matching of torque and power. The required torque and power vary in different operating conditions, such as full-load flat startup, flat-speed operation, climbing startup, and climbing-speed operation. For instance, the torque required for full-load flat startup is 16.318508771929825, and the motor’s rated torque must meet this requirement. The rated power is just a reference, as torque plays a more significant role in determining the AGV’s startup and climbing capability, while power is more related to speed and efficiency.

Motor Performance Characteristics
Motor speed remains relatively constant between 0-3000rpm, ensuring stable torque output. Additionally, the steering wheel can be overloaded, with the motor's maximum torque generally being three times the rated torque. This feature provides stronger power output under special conditions, but careful consideration is necessary during motor selection to ensure the motor operates within a reasonable load range under normal conditions.

4. Spring Selection and Vehicle Stability

Spring Parameter Calculation
Springs in AGVs provide buffering and support, and their selection involves several parameters. For example, the number of springs per drive wheel is 8, and by calculating the stress at different compression lengths, it ensures that the springs can handle the AGV's weight and load variations. For instance, at a compressed length of 78mm, the stress is 1466.7296897006022N. Accurate calculation of these parameters is crucial for ensuring stability and shock absorption during operation.

Spring Material Selection
The choice of spring material is also crucial. Different materials have varying stiffness moduli and characteristics. For example, carbon spring steel is strong and easy to process, but it cannot operate above 130°C, while silicon-manganese steel is suitable for variable loads, impact loads, and high-temperature environments. The selection of spring materials must consider the AGV’s operational environment and working requirements to ensure performance and longevity.

5. Conclusion

AGV design in automotive manufacturing logistics is a complex system engineering task. From setting basic parameters to calculating resistances under various operating conditions and selecting motors and springs, each step is interconnected. Only by comprehensively considering these factors and performing accurate calculations and rational selections can we design AGVs that are reliable and high-performing. As the automotive manufacturing industry continues to evolve, AGV designs will also be optimized and innovated to meet more complex and diversified production needs.