How Much Torque Does an AGV Need? A Payload-Based Answer with Engineering Standards

How Much Torque Does an AGV Need? A Payload-Based Answer with Engineering Standards

Engineers designing Automated Guided Vehicles (AGV) y robots móviles autónomos (AMR) routinely ask one question early in the project: how much torque does the drive motor actually need? The answer is never a single number. It depends on vehicle mass, acceleration target, slope angle, diámetro de la rueda, floor friction, number of driven wheels, gearbox ratio, and the thermal duty cycle the motor must sustain. This guide breaks the question down by payload class, provides force-model formulas you can apply immediately, and grounds the recommendations in international motor standards (CEI 60034-1, SIN MG 1) and manufacturer technical data from Maxon, faulhaber, y yaskawa.

Whether you are building a 50 kg indoor AMR or a 60-ton heavy-load transfer cart, the methodology below will get you to a defensible motor torque specification before you issue an RFQ.

Why Torque Sizing Determines AGV Success or Failure

Undersized torque causes motor stall under load, overheating during sustained operation, and failure to climb ramps. Oversized torque wastes battery capacity, increases wheel slip on smooth floors, and raises BOM cost without performance gain. In production environments, AGV reliability is rarely limited by control software — it is limited by the mechanical interaction between motor torque, wheel traction, y condiciones del suelo [1].

The torque requirement is not a single value but a profile across operating conditions. An AGV that moves smoothly on flat epoxy may stall on a 3% ramp. A motor that handles straight-line cruising may fail during in-place rotation, which typically demands two to five times the straight-line torque in differential-drive configurations [5].

The Quick Answer: Torque by Payload Class

If you need a ballpark before diving into formulas, the table below maps typical AGV payload classes to per-wheel continuous torque, recommended motor type, voltage platform, and gearbox ratio. These values assume 2 driven wheels, polyurethane tires on smooth concrete (Crr = 0.02), 0.5 m/s² acceleration, piso plano, and a safety factor of 1.5. They are starting points, not final specifications — always validate with the force model in the next section.

The torque values in Table 2 are per driven wheel. For a 2-wheel differential drive, the total tractive torque is double the per-wheel value. For a 4-wheel-drive configuration, divide the per-wheel value by 2 (assuming equal load distribution). Always recalculate using the formulas below for your specific operating conditions.

Force Model: Four Resistance Components

AGV drive torque is determined by the total resistance force the vehicle must overcome. The force model decomposes this into four components, each corresponding to a physical resistance source. This decomposition follows the methodology described in the MDPI Engineering Proceedings paper on motor parametric calculations for robot locomotion [9] and is consistent with the sizing approaches used by Oriental Motor [3] and iNetic Motion [4].

1. Resistencia a la rodadura (F_rollo)

Rolling resistance is the force required to deform the tire and floor at the contact patch. It depends on the tire material, floor surface, and normal load. Polyurethane tires on smooth epoxy have the lowest rolling resistance; rubber tires on rough concrete have the highest.

Fórmula: F_rollo = metro × gramo × C_RR × porque(i)

Dónde metro is gross vehicle mass (kg), gramo = 9.81 m/s², C_RR is the rolling resistance coefficient, y i is the slope angle. En terreno plano, porque(0°) = 1, so the term simplifies to m × g × C_RR.

2. Acceleration Force (F_acc)

Newton’s second law: the force required to accelerate the vehicle’s mass from rest to target speed. This is typically the largest force component during startup.

Fórmula: F_acc = metro × un

Dónde a is the target acceleration (m/s²). AGV acceleration is usually 0.3–0.8 m/s² for stability. AMRs may reach 1.0 m/s². Emergency deceleration can require 1.5–2.0 m/s², which produces the highest force transient.

3. Resistencia de grado (F_{calificación})

When the AGV operates on a ramp — loading dock approaches, floor transitions, or inclined transport paths — gravity adds a component parallel to the slope. This force can be substantial even on modest grades.

Fórmula: F_{calificación} = m × g × pecado(i)

A 1,200 kg AGV en un 3% ramp must overcome 353 N of grade resistance alone — nearly equal to its rolling resistance on flat ground. If your AGV encounters ramps, grade resistance often becomes the dominant force component.

4. Resistencia al giro (F_doblar) — Differential Drive Only

In differential-drive AGVs (dos ruedas motrices, múltiples ruedas), in-place rotation generates the highest torque demand. Caster wheels must pivot, creating significant scrub resistance. An engineering approximation from field data [5]:

Fórmula: F_girar = (2 ×F_rollo × √(W² + L²)) / W

Dónde W is wheel track width and L is vehicle length. En la práctica, rotation torque is 2–5× the straight-line torque, and it usually determines the peak torque rating of the motor.

Core Torque Formulas and Variables

Combining the four force components, the total driving force and wheel torque are calculated as follows. This formulation is consistent with the method described in the MDPI Engineering Proceedings paper [9] and the AGV Drive Wheel sizing guide [2].

Total Driving Force

F_total =F_rollo + F_acc + F_{calificación}

(Turning resistance is evaluated separately as a peak condition, not added to the continuous force.)

Per-Wheel Torque

T_rueda = (F_total ×r_rueda) / norte_conducir

Dónde riñonal_rueda es el cargado radio de la rueda (not the nominal radius — a polyurethane tire compresses 2–5 mm under load), y norte_conducir is the number of driven wheels sharing traction.

Motor-Side Continuous Torque

T_motor = (T_rueda × SF) / (yo × n_gramo)

Where SF is the safety factor (1.25–1.5 for indoor, 2.0 for heavy industrial, 2.5 for safety-critical), i is the gearbox reduction ratio, y la_gramo es la eficiencia de la caja de cambios.

Para aplicaciones AGV, two-stage planetary gearboxes are the most common choice because they offer the best balance of efficiency, densidad de par, and backlash. For an in-depth comparison of gearbox types, ver nuestro spur gear motor vs. motor de engranaje planetario análisis. Worm gearboxes are generally avoided in AGVs due to their low efficiency (which wastes battery capacity) and self-locking behavior (which prevents coasting and regenerative braking).

Power Check

PAGS_rueda =F_total ×v
PAGS_motor =P_rueda / (la_gramo × norte_motor)

Dónde v is target travel speed (EM), and η_motor is the motor efficiency (0.85–0.92 for BLDC at rated load). This power figure should include a 30–50% margin for surge, braking hold, and ramp startup.

Ejemplos resueltos: 150 kg AMR and 1,200 kg AGV

Ejemplo 1: 150 kg de RAM (Goods-to-Person Robot)

Resultado: A 150 kg AMR requires approximately 0.36 N·m continuous motor torque per drive wheel with a 20:1 caja de engranajes planetarios. A 24En motor BLDC in the 200–300 W range with a 42–57 mm frame size is appropriate. los complete AGV motor selection guide provides additional payload classes and motor model recommendations.

Ejemplo 2: 1,200 kg AGV (Assembly Line Transport)

Resultado: los 1,200 kg AGV requires approximately 3.04 N·m continuous motor torque per wheel with a 30:1 caja de cambios. A 48V BLDC motor in the 1–2 kW range (86–115 mm frame) is appropriate. Note that the grade resistance (353 norte) contributes 30% of the total force — if the AGV operates only on flat ground, the required torque drops to 2.2 N·m and the power to 1,540 W. This highlights why you must size for the worst-case operating point, not the average.

For a deeper treatment of torque calculation methodology, including differential-drive turning torque and inertia matching, ver nuestro Guía de cálculo del par del motor AGV with full force models and standard references.

Matriz de selección de motores basada en la carga útil

The table below synthesizes the calculations from the worked examples and extends them across the full payload range. It assumes 2-wheel differential drive, polyurethane tires on smooth concrete, 0.5 m/s² acceleration, and includes both flat-ground and 3% grade scenarios.

For custom motor specifications outside these standard payload classes, GreenSky Power offers custom electric motor design with frame sizes from 22 mm to 120 milímetro, voltage options from 12V to 72V DC, and integrated gearbox solutions.

Validación térmica: CEI 60034-1 Ciclos de trabajo

Torque alone does not guarantee motor survival. The motor must sustain the required torque within its thermal limits over the actual duty cycle. CEI 60034-1:2022 (Edición 15, published March 2026) defines ten duty cycle classifications, of which five are most relevant to AGV applications [7].

Most AGV applications fall under S3 or S4 duty. The key distinction: if your AGV starts and stops frequently (typical cycle: 10 seconds moving, 20 seconds loading), the motor winding does not fully cool between cycles, and the continuous torque rating must cover the RMS torque over the full cycle, not just the peak.

RMS Torque Calculation

For intermittent duty, calculate the RMS torque over one complete cycle:

T_RMS = √[(T₁²×t₁ + T₂²×t₂ + … + T_norte²×t_norte) / (t₁ + t₂ + … + T_norte)]

The motor’s rated continuous torque must exceed T_RMS at the operating ambient temperature. If T_RMS exceeds the rated torque, the motor will overheat — even if the peak torque is well within the motor’s capability.

Thermal Derating by Ambient Temperature

Motor torque ratings in datasheets are specified at 25°C ambient (per Maxon standard specification 100/101) [11]. A temperaturas ambiente más altas, the permissible continuous torque decreases.

If your AGV operates in a 40°C ambient (common in un-air-conditioned warehouses), you must derate the motor by 10–15%. A motor rated for 5 N·m continuous at 25°C delivers only 4.25–4.50 N·m at 40°C. For high-temperature environments, specify Class F (155° C) o Clase H (180° C) aislamiento, which allows 100% rated current up to 50°C ambient [12].

SIN MG 1 Torque Classifications for AGV Motors

SIN MG 1-2021 classifies motors into four design types based on torque characteristics and starting-load inertia. While NEMA standards are primarily used for AC induction motors, the torque classification framework is useful for understanding motor behavior under AGV startup conditions. IEC Design N and Design H classifications are roughly equivalent to NEMA Design B and C, respectivamente [8].

For BLDC motors used in AGVs, the NEMA design classification is less directly applicable because BLDC motors are electronically commutated and their torque-speed curve is determined by the controller, not the rotor design. Sin embargo, the concept of locked-rotor (a partir de) torque maps to the BLDC motor’s peak torque rating, which is typically 2–3× the continuous torque rating for 30–60 seconds before thermal protection activates.

The relationship between NEMA torque classifications and BLDC motor selection is discussed in our BLDC motor vs. servo motor comparación, which covers how electronic commutation changes the torque-speed envelope.

Pico vs.. Torque continuo: Why Most Sizing Errors Happen Here

The single most common mistake in AGV motor selection is sizing for peak torque without validating continuous thermal performance. Motor datasheets advertise peak torque prominently because it is the higher number, but peak torque is only available for a limited duration (typically 30–60 seconds) before the winding reaches its thermal limit.

Maxon specifies that motor constants have tolerances of up to ±10% and change with motor temperature — catalog values apply at 25°C, and a warm motor produces less torque [11]. Faulhaber’s DC Motors Technical Information notes that for optimal motor operation, the required speed should be higher than half the no-load speed, and the load torque should be less than the maximum continuous torque [12]. Yaskawa’s SigmaSelect sizing software generates a comparison report between servo system capability and application requirements, explicitly separating peak and continuous operating points [13].

Practical rule: Size the continuous torque to cover the RMS torque of the duty cycle (including derating for ambient temperature), then verify that the peak torque covers the worst-case transient. If the peak/continuous ratio of your selected motor is less than 2.0×, you may need a larger motor even if the continuous torque appears adequate.

Gearbox Matching: Reflected Torque and Inertia

The gearbox does more than reduce speed and multiply torque. It also transforms the load inertia as seen by the motor, which affects control stability and acceleration response.

Inercia reflejada

The load inertia reflected to the motor shaft is divided by the square of the gearbox ratio:

j_reflected = J_carga / i²

Dónde j_carga is the vehicle inertia at the wheel and i is the gearbox ratio. A 20:1 gearbox reduces the reflected inertia by a factor of 400, making the motor see a much smaller inertia. This is critical for servo-controlled AGVs where the inertia ratio affects tuning stability.

For AGV applications using BLDC motors with Hall-sensor feedback, an inertia ratio below 10:1 is generally acceptable because the velocity control loop does not require the precision of a position loop. For applications requiring precise positioning (p.ej., AGV docking), consider upgrading to a motor controller with encoder feedback and targeting an inertia ratio below 5:1.

Gearbox Selection for AGV Drives

For AGV drive systems, the gearbox ratio is selected to place the motor’s operating speed in its efficiency sweet spot (typically 1,500–3,000 RPM for BLDC motors). Abajo 1,000 RPM, torque ripple and cogging become noticeable; above 3,500 RPM, bearing life degrades and noise increases [12].

Nuestro spur vs. planetary gearbox comparison provides a detailed analysis of why planetary gearboxes are preferred for AGV applications — higher torque density, lower backlash, and coaxial output that simplifies wheel-hub integration. For applications requiring right-angle output (p.ej., steering drives), nuestro página de producto de la caja de cambios lists NMRV worm gearboxes and bevel-helical options.

Traction Verification: Preventing Wheel Slip

Calculating the required torque is necessary but not sufficient. The torque must be transmissible through the wheel-floor contact. If the applied torque exceeds the friction limit, the wheel slips — and encoder feedback becomes unreliable, directly affecting navigation accuracy [1].

Traction Limit Formula

F_{traction_max} = μ × N_conducir

Where μ is the static friction coefficient between wheel and floor, and N_conducir is the normal force on the driven wheel (not the total vehicle weight — only the weight borne by the driven wheels).

Verification rule: The per-wheel tractive force (F_total / norte_conducir) must not exceed F_{traction_max}. If it does, either increase the number of driven wheels, add ballast to increase normal force on driven wheels, or select a higher-friction tire compound.

Para AGV de tracción diferencial, the in-place rotation condition is the most likely to cause slip because all the tractive force is concentrated on two wheels pivoting in place. If the calculated F_girar exceeds the traction limit, the AGV will scrub instead of rotating cleanly, causing tire wear and position error.

Reading Motor Datasheets: Maxón, faulhaber, y yaskawa

Motor manufacturers present torque data in different formats. Understanding how to read these datasheets is essential for accurate AGV motor selection.

Maxón: Speed-Torque Line and Motor Constants

Maxon’s catalog specifies the speed-torque line, which is linear for coreless DC motors and BLDC motors with slotless windings. The key parameters are [11]:

• Torque constant (k_METRO) in mNm/A — the proportional relationship between current and torque. For coreless Maxon motors, torque and current are strictly proportional, allowing the motor to function as a torque sensor by measuring current.
• Speed-torque gradient (Δn/ΔM) in rpm/mNm — how much speed drops per unit of torque increase. A smaller value means a stiffer motor. The gradient is constant for most motors and equals the ratio of no-load speed to stall torque.
• Nominal torque (maximum continuous torque) — the torque the motor can deliver indefinitely at 25°C ambient without exceeding its thermal class.
• Stall torque — the torque at zero speed. Never an operating point; causes rapid overheating.

Maxon notes that motor constants have tolerances of up to ±10% and change with temperature. A warm motor is weaker — the speed-torque gradient increases as the motor heats up. This means a motor sized at the edge of its continuous torque rating at 25°C may be underpowered at 40°C ambient.

faulhaber: Operating Range and Thermal Limits

Faulhaber’s DC Motors Technical Information [12] defines the motor’s operating range on the speed-torque diagram, bounded by:

• Maximum continuous torque (thermal limit line) — the torque sustainable indefinitely.
• Velocidad máxima (mechanical limit) — determined by bearing and commutation capabilities.
• Maximum output power line — typically at 50% of stall torque and 50% of no-load speed.

Faulhaber recommends operating the motor such that the required speed is higher than half the no-load speed at nominal voltage, and the load torque is less than the maximum continuous torque. This ensures the motor operates in its efficient range and avoids excessive copper losses.

Yaskawa: SigmaSelect Sizing Methodology

Yaskawa’s SigmaSelect software [13] takes a system-level approach to servo motor selection. The user inputs:

• Application load data (masa, friction, external forces)
• Mechanical transmission parameters (gearbox ratio, eficiencia, inercia)
• Motion profile (velocidad, aceleración, dwell time)

The software then generates a report comparing the servo system’s capability (par máximo, continuous torque, velocidad, thermal capacity) against the application’s requirements (RMS torque, par máximo, velocidad máxima). This report format is valuable because it explicitly separates peak and continuous operating points and includes a thermal margin calculation. While Yaskawa’s SigmaSelect is designed for AC servo motors, the methodology applies directly to BLDC servo systems used in AGVs.

Seven Common Torque Sizing Mistakes

6-Step Torque Selection Workflow

The following workflow consolidates the methodology from this guide into a practical sequence for AGV motor selection. It is compatible with the approaches used by Oriental Motor’s AGV sizing tool [3], iNetic Motion’s calculator [4], and Yaskawa’s SigmaSelect [13].

For AGV applications requiring precise positioning (unión cósmica, pallet handling), also evaluate the servo motor vs. motor paso a paso tradeoff, and consider the direct drive vs. motorreductor comparison for hub-drive configurations. Nuestro BLDC vs. servo motors for AGVs analysis provides a three-layer comparison (BLDC estándar, servoBLDC, servo de CA) specific to AGV drive systems.

Preguntas frecuentes

How much torque does a typical AGV need?

It depends on payload. A 150 kg AMR needs approximately 0.4–0.7 N·m continuous motor torque per wheel (con un 20:1 caja de cambios). A 1,200 kg AGV needs 3–5 N·m. A 5-ton transfer cart needs 10–15 N·m. The quick-reference table in Section 2 provides values for five payload classes.

¿Cuál es la fórmula para el par del motor AGV??

T_motor = (F_total ×r_rueda × SF) / (norte_conducir × i × η_gramo), donde F_total =F_rollo + F_acc + F_{calificación}, SF is the safety factor, i is the gearbox ratio, and η_gramo es la eficiencia de la caja de cambios.

What safety factor should I use for AGV torque?

1.25–1.5 for indoor AMRs on smooth floors. 1.5–2.0 for industrial AGVs with ramps or frequent starts. 2.5 for safety-critical applications (médico, procesamiento de alimentos, molten metal transport). The safety factor covers measurement uncertainty, friction variation, and degradation over the motor’s service life.

How does slope angle affect AGV torque?

Grade resistance is F_{calificación} = m × g × pecado(i). A 3% ramp (1.72°) adds 294 N per 1,000 kg of mass. Por un 1,200 kg AGV, the grade force on a 3% ramp equals 353 N — nearly matching the rolling resistance. Always size for the worst-case slope in the operating environment.

Should I size for peak or continuous torque?

Both. The continuous torque must exceed the RMS torque of the duty cycle (validación térmica). The peak torque must exceed the worst-case transient (acceleration from standstill, ramp start, in-place rotation). Peak torque is typically 2–3× continuous for BLDC motors, available for 30–60 seconds.

What IEC standard applies to AGV motor torque?

CEI 60034-1:2022 defines duty cycle classifications (T1-T10). Most AGVs operate under S3 (intermittent periodic) or S4 (intermittent with starting influence). The motor’s rated torque must exceed the RMS torque at the operating ambient temperature, accounting for thermal derating per IEC 60034-1 thermal class limits.

Próximos pasos

If you have your AGV parameters ready — gross mass, target speed, aceleración, pendiente, wheel diameter — our engineering team can run the torque calculation and recommend a motor, caja de cambios, and controller combination. Contacte a GreenSky Power with your specifications, or browse our complete motor product catalog for BLDC motors, reductores planetarios, y controladores de motores suitable for AGV drive systems.

All GreenSky Power motors are tested per CEI 60034 y GB/T 1032 testing standards, with dynamometer test reports included with every shipment. For AGV-specific applications, we offer custom motor design with integrated encoder, freno, and gearbox options.

Referencias

1. Honest Edrive Equipment Co., Limitado. (2026). Esfuerzo de torsión, Tracción, and Tread: Engineering Factors in AGV Drive Wheels. Retrieved from https://www.hagvwheel.com/engineering-factors-in-agv-drive-wheels.html
2. Rueda motriz AGV. (2026). Cómo calcular el par de torsión de la rueda motriz del AGV y el tamaño del motor. Retrieved from https://agvdrivewheel.com/blog/how-to-calculate-agv-drive-wheel-torque-and-motor-sizing
3. motores orientales. (2026). AGV: herramienta de dimensionamiento de vehículos guiada automáticamente. Retrieved from https://www.orientalmotor.com/motor-sizing/agv-sizing.html
4. iNetic Motion. (2026). AGV & AMR Motor Calculator for Robotics and Mobility. Retrieved from https://ineticmotion.com/agv-motor-calculator/
5. Equipo inteligente Yikong (bicontroles). (2026). Guía de dimensionamiento del motor AGV de rueda motriz diferencial: Cálculo de par y adaptación de inercia. Retrieved from https://en.bicontrols.com/news_detail/104.html
6. Equipo inteligente Yikong (bicontroles). (2025). Torque Calculation and Optimization for AGV Drive Motors: Enabling Flexible Logistics in Automotive Manufacturing. Retrieved from https://en.bicontrols.com/news_detail/50.html
7. Comisión Electrotécnica Internacional. (2026). CEI 60034-1:2022 — Rotating Electrical Machines — Part 1: Rating and Performance. Edición 15. Ginebra: CEI. Obtenido de https://www.iec.ch/government-regulators/electric-motors
8. Engineering ToolBox. (2026). Electric Motors — IEC and NEMA Standard Torques. Retrieved from https://www.engineeringtoolbox.com/iec-nema-standards-torques-d_741.html
9. Siddiqui, F. A., et al. (2022). “Motor Parametric Calculations for Robot Locomotion.” Procedimientos de ingeniería, 20(1), 8. MDPI. Retrieved from https://www.mdpi.com/2673-4591/20/1/8
10. DFRobot. (2025). How to Calculate the Motor Torque for a Mobile Robot. Retrieved from https://wiki.dfrobot.com/tutorial/20135
11. Grupo Maxon. (2025). Motor Data and Simulation — maxon Support. Standard Specification 100 (Motor de corriente continua) / 101 (EC Motor). Retrieved from https://support.maxongroup.com/hc/en-us/articles/360013761160-Motor-data-and-simulation
12. Dr. Fritz Faulhaber GmbH & Co. KG. (2022). Technical Information: Motores CC. Retrieved from https://www.faulhaber.com/fileadmin/Import/Media/EN_TECHNICAL_INFORMATION.pdf
13. Yaskawa América, Cª. (2025). SigmaSelect Servo Sizing Software — Product Overview. Retrieved from https://www.yaskawa.com/products/motion/sigma-7-servo-products/software-tools/sigmaselect
14. University of Florida, Machine Design Lab. (2015). Useful Motor/Torque Equations for EML2322L. Retrieved from https://web.mae.ufl.edu/designlab/motors/Useful%20Equations.pdf
15. AGV Motor. (2025). AGV/AMR Design Calculator: Key Points from Parameter Calculations to Selection Guidelines. Retrieved from https://agvmotor.com/blogs/knowledge/agv-amr-design-calculator-key-points-from-parameter-calculations-to-selection-guidelines