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AGV Motor Speed and RPM Selection Guide: Fórmulas, Estándares & Ejemplos resueltos

AGV Motor Speed and RPM Selection Guide

AGV Motor Speed and RPM Selection Guide: Fórmulas, Estándares & Ejemplos resueltos

Selecting the right motor speed for an Automated Guided Vehicle (AGV) is not a single-parameter decision. It sits at the intersection of vehicle dynamics, gearbox design, battery constraints, and control-loop bandwidth. Get it wrong and you face either a sluggish robot that cannot meet throughput targets, or an over-speeding motor that overheats, wastes battery, and dies prematurely. This guide walks through the full engineering chain—from the fundamental speed-to-velocity formula through IEC 60034-1 duty cycle classification, NEMA MG1 design types, and manufacturer datasheet interpretation—to give you a repeatable workflow for matching motor RPM to any AGV platform.

Why Motor Speed Defines AGV Performance

Motor rated speed (RPM) directly governs three AGV performance pillars:

Performance PillarHow Motor Speed Affects ItConsequence of Mismatch
Travel VelocityWheel speed = motor RPM ÷ gear ratio; vehicle speed = wheel RPM × wheel circumferenceMotor too slow → AGV cannot meet cycle-time targets; motor too fast → excessive gear ratio needed, efficiency drops
Densidad de parFor a given power, higher-speed motors are smaller and lighter but produce less torque per ampUndersized torque → stall on ramps, sluggish acceleration; oversized motor → wasted payload capacity and cost
Battery RuntimeBLDC motors peak in efficiency at 70–90% of rated RPM; operating far below this wastes energy as heatPoor efficiency zone → 15–30% shorter battery life per charge cycle, more charging stops, lower fleet OEE

Industry data from AGV fleet operators shows that motors consistently running below 50% of rated RPM—common in over-geared designs—experience 20–35% higher energy consumption and 40% shorter bearing life compared to motors operating in their optimal efficiency band [1].

Respuesta rápida: Motor RPM Ranges by AGV Payload Class

For engineering teams that need a fast reference before diving into calculations, the table below consolidates field-proven motor RPM ranges across six AGV payload categories. These values assume BLDC or BLDC servo motors paired with single-stage planetary gearboxes (efficiency ≥ 90%) and polyurethane wheels on epoxy floors.

Payload ClassTypical AGV TypeMotor Rated RPMRango de relación de transmisiónWheel RPM (output)Vehicle SpeedPotencia del motorVoltaje
≤ 100 kgAGC / RAM ligera3,000–5,0005:1–10:1300–6000.8–2,0 m/s50–100 W24V
100–300 kilogramosWarehouse AMR3,000–4,00010:1–15:1200–4000.8–1,5 m/s100–200 W24V / 48V
300–600 kgUnder-Riding AGV2,500–3,5008:1–15:1150–3500.5–1,5 m/s200–400 W48V
600–1,200 kgTowing / Pallet AGV2,500–4,0006:1–15:1100–3000.5–1,5 m/s400–750 W48V
1,200–3.000 kilogramosCarretilla elevadora AGV2,000–3,00012:1–25:180–2000.3–1,0 m/s750–1,500 W48V / 72V
3,000–20,000 kgHeavy-Duty AGV1,500–2,50015:1–30:150–1200.2–0,5 m/s1.5–5 kW+72V / 80V

Source: Consolidated from AGV manufacturer specifications [2][3], gear motor supplier data [4], and GreenSky Power’s AGV motor application guide [5].

The Speed–Torque–Gear Ratio Triangle

Every AGV drive design lives within a three-variable trade space. You cannot optimize one without affecting the other two. Understanding this triangle prevents the most common error in motor speed selection: choosing a motor based on speed alone and discovering the torque is inadequate only during prototype testing.

Variable 1: Velocidad nominal del motor (nortenorte)

The rated speed is the RPM at which the motor delivers its rated torque continuously without exceeding its thermal class limit. For BLDC motors used in AGVs, this typically falls between 1,500 y 5,000 RPM. The rated speed is not the no-load speed (norte0)—the no-load speed is typically 10–20% higher than the rated speed under load [6].

Variable 2: Gearbox Reduction Ratio (i)

The ratio converts motor shaft speed to wheel shaft speed. A higher ratio reduces output speed but multiplies output torque (minus gearbox efficiency losses). Para aplicaciones AGV, ratios typically range from 5:1 (light AMR) a 50:1 (heavy-duty), con 15:1–25:1 being the most common range for warehouse AMRs [5].

Variable 3: Output Torque at Wheel (Trueda)

This is the torque that actually reaches the drive wheel after gearbox reduction: Trueda =Tmotor × i × η, where η is gearbox efficiency (0.90–0.95 for planetary, 0.60–0.70 for worm gear). The wheel torque must exceed the sum of rolling resistance, gradient resistance, and acceleration inertia torque with a safety margin of 1.3–1.5× [7].

Design ChoiceSpeed EffectEfficiency EffectWhen to Choose
High motor RPM + high ratioNormal–High vehicle speedHigh wheel torque (ratio multiplies motor torque)Good if motor stays in 70–90% rated RPM bandStandard warehouse AGV/AMR (recommended)
Low motor RPM + low ratioLower vehicle speedModerate wheel torqueRisk: motor may operate below optimal efficiency zonePrecision positioning AGV, cleanroom robots
High motor RPM + low ratioVery high vehicle speedLow wheel torqueRisk: insufficient acceleration torque, wheel slipLong-distance towing AGV on flat floors
Low motor RPM + high ratioVery low vehicle speedVery high wheel torqueRisk: motor overheating at low RPM, poor coolingAGV de servicio pesado (5+ montones) with multi-motor drive

Fórmula central: Motor RPM to Vehicle Speed

The fundamental equation linking motor speed to AGV linear velocity is:

v = (2 × π × r × nmotor) ÷ (60 × yo)

Dónde:

  • v = AGV travel speed (EM)
  • riñonal = drive wheel radius (metro)
  • nortemotor = motor rotational speed (RPM)
  • i = gearbox reduction ratio (sin dimensiones)

Reverse Calculation: Deriving Gear Ratio from Target Speed

En la práctica, engineers usually know the desired vehicle speed and wheel diameter, then solve for the required gear ratio given a motor’s rated RPM:

i = (2 × π × r × nmotor) ÷ (60 ×v)

For quick estimates, the wheel RPM can be calculated independently:

norterueda = (v× 60) ÷ (π × D) where D = wheel diameter (metro)

Entonces: i = nmotor ÷ nrueda

Numerical Example

Target: 1.2 m/s travel speed, 200 mm wheel diameter (r= 0.1 metro), motor rated at 3,000 RPM.

  1. Wheel RPM = (1.2 × 60) ÷ (pag × 0.2) = 72 ÷ 0.628 ≈ 114.6 RPM
  2. Gear ratio = 3,000 ÷ 114.6 ≈ 26.2
  3. Select standard ratio 25:1 o 30:1 (nearest available)
  4. Verify actual speed at 25:1: v = (2pag × 0.1 × 3000) ÷ (60 × 25) = 1.256 m/s ✓
  5. Verify actual speed at 30:1: v = (2pag × 0.1 × 3000) ÷ (60 × 30) = 1.047 EM (slightly below target)

This example illustrates why motor speed selection and gear ratio selection must be performed iteratively—you rarely get an exact match with standard ratios [3][7].

Reading the Speed-Torque Curve: Maxon and Faulhaber Methodology

Motor datasheets from leading manufacturers like Maxón y faulhaber present speed-torque characteristics as a linear graph. Understanding how to read this graph is essential for verifying that your selected motor speed will deliver the required torque under actual AGV load conditions.

The Speed-Torque Line (Maxon Methodology)

Maxon’s motor selection methodology defines the speed-torque relationship as a straight line from no-load speed (norte0) at zero torque to stall torque (METROH) at zero speed [6]:

n = n0 - (Δn/ΔM) × M

Dónde:

  • norte0 = knorte × UMot (no-load speed = speed constant × applied voltage)
  • Δn/ΔM = speed-torque gradient (slope of the line, in RPM per mNm)
  • METRO = instantaneous motor torque

Key insight from Maxon: the slope Δn/ΔM is a mechanical constant determined by the motor’s winding geometry and magnetic circuit—it does not change with voltage. Changing the applied voltage shifts the line up or down (parallel translation) but does not change the slope. This means a motor’spowerfulness” (how much speed it retains under load) is fixed by design, not by the supply voltage [6].

Operating Range Rules (Faulhaber Methodology)

Faulhaber’s DC motor technical documentation recommends that for optimal motor life and efficiency, the operating point should satisfy [8]:

  • Required speed n ≥ n0 / 2 (operate above half the no-load speed)
  • Required load torque M ≤ MH / 2 (operate below half the stall torque)
  • For continuous duty: stay within the continuous operation zone defined by the thermal limit curve

Para aplicaciones AGV, this translates to a practical rule: select a motor whose rated speed is 1.5–2× the speed you actually need at the motor shaft, then use the gearbox ratio to reduce to the target wheel speed. This keeps the motor in its efficient upper-speed zone and leaves torque headroom for acceleration transients [6][8].

Maxon’s 20% Tolerance Rule

When selecting a motor winding for a specific AGV application, Maxon recommends adding a 20% margin to the calculated speed constant to account for tolerances in winding resistance, magnet strength, and load variability [6]:

knorte 1.2 × (nortemax,requerido + (Δn/ΔM)avg × Mmax) ÷ UMot

This ensures that even with manufacturing tolerances (Maxon publishes ±10% on no-load speed and ±50% on no-load current), the motor will still meet the AGV’s speed requirement under worst-case conditions [9].

Gearbox Ratio Selection by AGV Type

Different AGV architectures demand different speed-torque trade-offs. The table below maps six common AGV types to their recommended motor RPM, relación de transmisión, and output characteristics, based on consolidated data from AGV motor manufacturers and system integrators [2][3][5].

Tipo AGVRPM del motorRelación de transmisiónOutput CharacteristicRecommended GearboxKey Design Constraint
Under-Riding AGV2,500–3,5008:1–12:1Baja velocidad, alto par, precise positioningPlanetario (low backlash ≤ 5 arco-min)Top-lift torque must exceed full-load gravity torque
Carretilla elevadora AGV2,000–3,00012:1–20:1Ultra-high starting torque, strong brakingPlanetario (2-etapa) or worm gear (self-locking)Torque priority over speed; electromagnetic brake required
Towing AGV2,500–4,0006:1–10:1Medium speed, long continuous runPlanetario (helicoidal, alta eficiencia)Thermal management for extended duty cycles
Load-Carrying AGV3,000–4,0005:1–8:1Respuesta rápida, agile steeringCompact planetary or integrated drive wheelBalance speed and acceleration performance
Differential Drive AGV3,000–4,5005:1–8:1Respuesta rápida, sensitive steering controlLow-backlash planetary (≤ 3 arco-min)Left/right wheel torque matching for straight-line tracking
Heavy-Duty AGV (5–20t)1,500–2,50015:1–25:1Extreme torque, low-speed stabilityMulti-stage planetary (2–3 stage)Multi-motor synchronized drive; redundant cooling

Gearbox Efficiency Impact on Effective Speed

The gearbox efficiency directly reduces the output torque (and thus the effective tractive force), but it does not change the output speed. Sin embargo, because the motor must produce more torque to compensate for gearbox losses, the motor’s actual operating speed drops along the speed-torque line. This means a worm gearbox (h = 0.65) causes the motor to run 10–15% slower than a planetary gearbox (h = 0.92) at the same load, because the motor must deliver more torque to achieve the same wheel output [7].

Tipo de caja de cambiosEficienciaMax Single-Stage RatioReacciónNivel de ruidoAGV Suitability
Planetario90–95%3:1–10:1 (hasta 100:1 multi-stage)3–15 minutos de arcoBajoStandard for all AGV types
Worm Gear60–75%5:1–60:115–30 arc-minBajoCarretilla elevadora AGV (self-locking benefit)
Parallel Shaft90–94%3:1–30:115–30 arc-minModeradoLight-load AGV, cost-sensitive
Harmonic Drive85–90%50:1–200:1≤ 1 arco-minMuy bajoPrecision positioning, articulaciones robóticas

CEI 60034-1: Duty Cycle Classifications for AGV Speed Selection

Motor speed selection cannot be separated from thermal considerations. CEI 60034-1:2022 (Edición 15) defines ten duty cycle classifications (T1-T10) that determine how long a motor can sustain its rated speed and torque without exceeding thermal limits. Para aplicaciones AGV, three classifications are most relevant [10][11].

S1 — Continuous Duty

The motor runs at constant rated load long enough to reach thermal steady state. This applies to towing AGVs on long-distance transport loops. The rated speed and torque on the motor nameplate are S1 values—selecting a motor based on nameplate ratings is safe only if your AGV operates in S1 mode.

S3 — Intermittent Periodic Duty

The motor cycles between run and stop periods without significant thermal equilibrium. This is the most common AGV duty cycle: pick-up → travel → drop-off → idle → repeat. S3 is expressed as a percentage (p.ej., S3-40% means the motor is energized 40% of the cycle time). A motor rated for S3-40% can deliver 1.6× its S1 torque during the on-period, but only if the off-period provides sufficient cooling.

S4 — Intermittent Periodic Duty with Starting

Similar to S3 but includes a significant starting (aceleración) phase that contributes to heating. This applies to AGVs with frequent start-stop cycles (p.ej., warehouse AMRs navigating through aisles with obstacle avoidance).

CEI 60034-1 ClaseSolicitud AGVThermal Impact on SpeedDerating Factor vs. T1Insulation Class Recommendation
T1 (Continuo)Towing AGV, long-distance transportFull thermal load; rated speed = max continuous speed1.0 (baseline)Clase F (155° C) minimum
S3-40% (Intermitente)Warehouse AMR, pallet moverMotor can run at higher torque between rests; speed maintained during on-period1.6× torque during on-periodClase F (155° C) or Class B (130° C)
T4 (Intermitente + Starting)High-frequency pick-and-place AGVStarting current adds thermal load; effective continuous speed reduced1.3–1.5× torque, shorter dutyClase F (155° C) recommended
T2 (Short-Time)AGV steering motor (intermittent rotation)Rated for short burst; must cool before next cycle2.0× torque for ≤ 30 minClase B (130° C) acceptable

For AGV motor selection, the practical implication is: if your AGV operates in S3 or S4 mode, you can select a motor with a lower S1-rated speed than a pure S1 calculation would suggest, because the intermittent duty allows the motor to run harder during active periods. Sin embargo, you must verify that the RMS (media cuadrática) torque over the full cycle does not exceed the motor’s S1 rated torque [11].

SIN MG 1: Standard Speed Ratings and Design Types

While AGV motors are typically DC-powered (BLDC o cepillado), many AGV systems in North American facilities also integrate AC induction motors for auxiliary functions (zapatillas, ascensores, transportadores). SIN MG 1-2021 defines standard speed ratings that engineers should recognize when specifying complete AGV systems [12].

NEMA Standard Speeds at 60 Hz

The synchronous speed of an AC motor is determined by the formula: nortes = 120 × f ÷ P, where f = frequency (Hz) and P = number of poles.

polacosVelocidad sincrónica (60 Hz)Typical Full-Load SpeedSolicitud AGV
23,600 RPM3,450–3,540 RPMHigh-speed auxiliary pump (rare in AGV)
41,800 RPM1,725–1,780 RPMHydraulic lift pump motor
61,200 RPM1,140–1,175 RPMConveyor drive (on-board AGV belt)
8900 RPM850–870 RPMLow-speed high-torque auxiliary

NEMA Design Types and IEC Equivalents

SIN MG 1 classifies motor designs by their torque-speed characteristics. For AGV auxiliary AC motors, the design type determines starting behavior under load [12][13].

Diseño NEMAIEC EquivalentPar inicialPar de rupturaSlip at Full LoadAGV Suitability
Diseño ANormalAlto (>200%)< 5%Not recommended (high starting current)
Diseño BDesign NNormal (150–280%)200–250%3–5%Standard AGV auxiliary motors (most common)
Diseño CDesign HAlto (200–250%)190–225%3–5%AGV hydraulic lift (alto par de arranque)
Diseño Dmuy alto (275%+)5–13%AGV traction (high slip, alto par de arranque)

For the primary AGV drive motor (BLDC), SIN MG 1 design types do not directly apply, but the thermal class and insulation rating standards are shared. Most AGV-grade BLDC motors use Clase F (155° C) aislamiento per IEC 60034-1 / SIN MG 1, with Class H (180° C) for high-ambient or heavy-duty applications [10][12].

Motor Speed Constants: knorte, kT, and Speed-Torque Gradient

Three constants define a motor’s speed behavior. Understanding them is essential for interpreting manufacturer datasheets and performing speed calculations that go beyond simple ratio division.

Speed Constant (knorte)

Expressed in RPM per volt (RPM/V). Defines the no-load speed at a given voltage: norte0 = knorte × U. A higher knorte means the motor spins faster at the same voltage but produces less torque per amp. For AGV BLDC motors, knorte values typically range from 50–300 RPM/V (at 24V: 1,200–7,200 RPM no-load) [6].

Torque constante (kT or kMETRO)

Expressed in Nm/A (or mNm/A for small motors). Defines the torque produced per amp of current: M = KT × yo. Maxon notes that for their motors, torque and current are directly proportional, meaning the current axis on a speed-torque graph can be read as a parallel torque axis. Typical AGV BLDC motor KT values range from 0.02–0.5 Nm/A [6].

Speed-Torque Gradient (Δn/ΔM)

Expressed in RPM per Nm (or RPM per mNm for small motors). Defines how much speed drops per unit of load torque increase: Δn/ΔM = n0 ÷ MH (no-load speed divided by stall torque). A flatter gradient (smaller value) means a more powerful motor that maintains speed under load. Maxon considers this the most meaningful single number for motor comparison, as it is a mechanical constant independent of winding choice [6].

Motor Size (AGV Class)Typical knorte (RPM/V)K típicoT (Nm/A)Typical Δn/ΔM (RPM/mNm)No-Load Speed at 24VRated Speed at 24V
57marco de mm (≤100W)150–3000.02–0.055–153,600–7,2003,000–5,000
80marco de mm (200-400W)80–1500.05–0.153–81,920–3,6002,500–3,500
100marco de mm (500–750W)50–1000.10–0.302–51,200–2,4002,000–3,000
120mm+ frame (1kilovatios+)30–600.20–0.501–3720–1,4401,500–2,500

Nota: Maxon publishes ±10% tolerance on no-load speed and ±50% tolerance on no-load current. Always include this tolerance in speed calculations, especially for AGV fleets where multiple motors must track the same speed [9].

Closed-Loop Speed Control: Encoder Resolution and PWM

Selecting the motor’s rated RPM is only half the equation—maintaining that speed precisely under varying load requires closed-loop control. AGV systems use encoder feedback to achieve speed regulation accuracy of ±0.5% to ±1.0% for standard industrial AGVs, and ±0.1% for high-precision positioning AGVs [3].

Encoder Resolution Impact on Speed Control

The encoder’s pulses per revolution (PPR) determines the minimum speed increment the controller can resolve:

Speed resolution = 60 ÷ (PPR × Tsample) (RPM)

Where Tsample is the control loop sampling period in seconds. En 5 ms loop time (200 Hz update rate, typical for AGV motor controllers):

Encoder PPRSpeed Resolution at 5ms LoopMin Detectable Speed ChangeTypical AGV Application
1,000 PPR12 RPM±0.4% at 3,000 RPMLow-cost AMR, AGC
2,500 PPR4.8 RPM±0.16% at 3,000 RPMStandard warehouse AGV
5,000 PPR2.4 RPM±0.08% at 3,000 RPMPrecision positioning AGV
17-poco absoluto (131,072)0.09 RPM±0.003% at 3,000 RPMCarretilla elevadora AGV, high-precision docking

PWM Frequency and Speed Ripple

The servo drive’s PWM switching frequency affects speed smoothness at the motor shaft. Typical AGV BLDC controllers use 16–20 kHz PWM, which is above the audible threshold and provides smooth current regulation. At lower PWM frequencies (8–10 kHz), speed ripple increases, causing visible wheel jitter at low speeds—an issue for AGVs performing precision docking [3].

Yaskawa Servo Speed Control Architecture

Yaskawa’s Sigma-5 and Sigma-X servo systems, widely used in industrial automation, illustrate best-in-class speed control architecture for AGV-class applications. The Sigma-5 series supports maximum speeds of 6,000 RPM (low-inertia) y 3,000 RPM (medium-inertia) with 20-bit (1,044,576 recuentos/revoluciones) encoder resolution. The speed control loop typically operates at 62.5 μs (16 khz), enabling ±0.01% speed regulation—well beyond AGV requirements but illustrative of what closed-loop servo architecture achieves [14][15].

ParámetroStandard BLDC ControllerServomotor BLDC (mid-range)Yaskawa Sigma-5/X
Speed loop bandwidth200–500 Hz500–1,000 Hz1,000–2,500 Hz
Encoder resolution1,000–2,500 PPR2,500–5.000 PPR20-poco / 26-poco absoluto
Regulación de velocidad±0.5–1.0%±0.1–0.5%±0.01%
Max motor speed3,000–5,000 RPM3,000–6,000 RPM3,000–7,000 RPM
Par máximo150–200% valorado200–300% valorado300–350% rated

Voltage Platform and Its Impact on Speed Range

AGV battery voltage directly constrains the motor’s achievable speed through the speed constant relationship (norte0 = knorte × U). Lower-voltage systems limit the maximum no-load speed, which in turn limits the available speed headroom for gear ratio optimization.

Battery VoltageCarga útil típica de AGVMax Practical Motor RPMCurrent at Rated PowerWire/Connector Loss ImpactRecommended Motor Type
24V≤ 300 kg3,000–5,000Alto (8–20A per 100W)Significant at >15A; use short runsBLDC (small frame)
48V300–1,500 kg2,500–4,000Moderado (4–10A per 100W)Manageable; standard in warehouse AGVservoBLDC (mainstream)
72V1,500–3.000 kilogramos2,000–3,500Más bajo (3–7A per 100W)Mínimo; allows longer cable runsservoBLDC (high-power)
80V+3,000+ kg1,500–3,000Bajo (2–5A per 100W)Mínimo; heavy-duty cablingservoBLDC / servo de CA (with inverter)

A critical design note: never operate a motor significantly below its rated voltage. A 48V-rated motor running on a 24V bus will only reach half its rated no-load speed, pushing the operating point into the low-efficiency zone and potentially causing thermal issues due to high current draw [3].

Ejemplo resuelto 1: 500 kg Warehouse AMR

Design Requirements

  • masa total (vehicle + carga útil): 500 kg
  • Target travel speed: 1.5 EM
  • Diámetro de la rueda: 200 milímetro (r= 0.1 metro)
  • Maximum gradient: 3% (1.7°)
  • Acceleration target: 0.5 m/s²
  • Batería: 48VCC
  • ciclo de trabajo: S3-40% (warehouse pick-and-place)

Step-by-Step Speed Selection

PasoAcciónCalculationResultado
1Calculate required wheel RPMnorterueda = (1.5 × 60) ÷ (pag × 0.2)143.2 RPM
2Select motor rated RPM (1.5–2× headroom)Target motor RPM = 143.2 × 20 (initial ratio guess)~2,864 RPM → select 3,000 RPM motor
3Calculate gear ratioi = 3,000 ÷ 143.220.9 → select standard 20:1
4Verify actual speed at 20:1v = (2pag × 0.1 × 3000) ÷ (60 × 20)1.57 m/s ✓ (exceeds 1.5 objetivo)
5Calculate rolling resistance forceFF = 0.015 × 500 × 9.8173.6 norte
6Calculate gradient resistance forceFi = 0.03 × 500 × 9.81147.2 norte
7Calculate acceleration resistance forceFa = 500 × 0.5250 norte
8Calculate total resistance (cima)Ftotal = 73.6 + 147.2 + 250470.8 norte
9Calculate required wheel torqueTrueda = 470.8 × 0.147.1 Nuevo Méjico
10Calculate required motor torque (at 20:1, η=0.92)Tmotor = 47.1 ÷ (20 × 0.92)2.56 Nuevo Méjico
11Aplicar factor de seguridad (1.3×)Tmotor,clasificado = 2.56 × 1.33.33 Nuevo Méjico
12Select motor: 48V, 3,000 RPM, ≥3.3 Nm rated torqueCheck datasheet speed-torque curve at 3,000 RPMConfirm rated torque ≥ 3.3 Nm at 3,000 RPM
13Verify RMS torque for S3-40% dutyTrms = √[(Tcima² × 0.4 + Tidle² × 0.6)]Verify Trms ≤ motor S1 rated torque

Resultado: Select a 48V BLDC servo motor rated at 3,000 RPM with ≥ 3.3 Nm continuous rated torque, paired with a 20:1 single-stage planetary gearbox (η ≥ 92%, backlash ≤ 10 arco-min). This configuration delivers 1.57 m/s top speed with adequate torque margin for 3% gradients and 0.5 m/s² acceleration under 500 kg total mass [5][7].

Ejemplo resuelto 2: 2,000 kg Forklift AGV

Design Requirements

  • masa total: 2,000 kg
  • Target travel speed: 0.8 EM
  • Diámetro de la rueda: 300 milímetro (r= 0.15 metro)
  • Maximum gradient: 5% (2.9°)
  • Acceleration target: 0.3 m/s²
  • Batería: 72VCC
  • ciclo de trabajo: T4 (frequent start-stop with lifting)

Step-by-Step Speed Selection

PasoAcciónCalculationResultado
1Calculate required wheel RPMnorterueda = (0.8 × 60) ÷ (pag × 0.3)50.9 RPM
2Select motor rated RPM (heavy-duty, velocidad más baja)Target: 2,500 RPM (per payload class table)2,500 RPM
3Calculate gear ratioi = 2,500 ÷ 50.949.1 → select 50:1 (2-etapa planetaria)
4Verify actual speed at 50:1v = (2pag × 0.15 × 2500) ÷ (60 × 50)0.785 EM (slightly below 0.8; acceptable with 2% margin)
5Calculate rolling resistance forceFF = 0.015 × 2000 × 9.81294.3 norte
6Calculate gradient resistance force (5%)Fi = 0.05 × 2000 × 9.81981.0 norte
7Calculate acceleration resistance forceFa = 2000 × 0.3600 norte
8Calculate total resistance (cima)Ftotal = 294.3 + 981.0 + 6001,875.3 norte
9Calculate required wheel torque (dual drive)Trueda,per = (1875.3 ÷ 2) × 0.15140.6 Nm per wheel
10Calculate required motor torque (50:1, η=0.88 for 2-stage)Tmotor = 140.6 ÷ (50 × 0.88)3.20 Nuevo Méjico
11Aplicar factor de seguridad (1.5× for S4 duty)Tmotor,clasificado = 3.20 × 1.54.80 Nuevo Méjico
12Select motor: 72V, 2,500 RPM, ≥4.8 Nm rated torqueCheck datasheet; verify thermal class F or HConfirm; add temperature sensor for S4 monitoring

Resultado: Dual 72V BLDC servo motors, 2,500 RPM, 4.8 Nm rated torque each, con 50:1 2-reductores planetarios de etapa (η ≥ 88%), delivering 0.79 m/s top speed and 1,875 N peak tractive force for 2,000 kg forklift AGV on 5% gradients. The S4 duty cycle requires Class F insulation and integrated thermal sensors [7][10].

Common Speed Selection Mistakes

#ErrorWhat HappensHow to Avoid
1Using no-load speed instead of rated speed for ratio calculationDC motor no-load speed is 10–20% higher than loaded speed; using it produces a ratio that delivers 10–20% less output speed than intendedAlways use the speed at rated torque (from the speed-torque curve) for ratio calculations [4]
2Selecting ratio based on speed only, ignoring torque verificationRatio delivers correct speed but output torque is insufficient; motor stalls on ramps or during accelerationComplete both speed calculation and torque verification before finalizing [4]
3Choosing excessively high ratiofor extra torqueMotor operates at very low speed, outside efficient zone; calentamiento excesivo, poor cooling, wasted speed rangeMatch ratio to required speed with appropriate torque margin (1.3–1,5×), not maximum ratio [4]
4Ignoring gearbox efficiency in motor speed calculationMotor must produce more torque than calculated, pushing operating point down the speed-torque line; actual speed 5–15% lower than expectedInclude gearbox η in torque calculation; verify resulting motor speed on speed-torque curve [7]
5Selecting motor voltage below battery bus voltageMotor reaches only fraction of rated speed; high current draw, thermal issues, eficiencia reducidaMatch motor rated voltage to battery nominal voltage; never undervolt significantly [3]
6Not verifying RMS torque for intermittent dutyMotor passes peak torque check but fails thermal check over full cycle; overheating during multi-shift operationCalculate RMS torque over full duty cycle; verify ≤ S1 rated torque per IEC 60034-1 [11]
7Ignoring motor speed tolerances (Maxon ±10% on n0)Fleet motors run at different speeds; straight-line tracking fails, differential AGV veers off courseApply 20% margin per Maxon methodology; use closed-loop speed synchronization [6][9]

7-Step Motor Speed Selection Workflow

Based on the engineering principles, estándares, and manufacturer methodologies covered above, the following workflow provides a repeatable process for AGV motor speed selection:

PasoAcciónInputProducciónEstándar / Reference
1Definir los parámetros del vehículo.masa total, target speed, max gradient, aceleración, diámetro de la rueda, voltaje de la bateríaDesign requirement sheet
2Calculate required wheel RPMnorterueda = (v× 60) ÷ (π × D)Wheel RPM at target speedBasic kinematics
3Select motor rated RPM from payload class tablePayload class → motor RPM range (see Quick Answer table)Candidate motor RPM[2][5]
4Calculate gear ratio and verify speedi = nmotor ÷ nrueda; verify v = (2π × r × nmotor) ÷ (60 × yo)Candidate ratio; verified speed[3][7]
5Verify torque on speed-torque curveCalculate Tmotor =Trueda ÷ (yo × n); apply 1.3–1.5× safety; check on datasheet curve at rated RPMConfirmed motor torque ratingMaxon methodology [6]; Faulhaber rules [8]
6Verify thermal duty cycleDetermine IEC 60034-1 duty class (S1/S3/S4); calculate RMS torque; verify ≤ S1 rated torqueThermal pass/fail; insulation classCEI 60034-1:2022 [10][11]
7Apply tolerance margin and finalizeAgregar 20% speed margin (Maxon rule); select standard ratio; specify encoder PPR and IP ratingFinal motor + gearbox specificationMaxon tolerance [9]; SIN MG 1 [12]

Academic Research on AGV Motor Speed Optimization

Several peer-reviewed IEEE papers have addressed motor speed optimization for AGV and mobile robot platforms:

  • Energy-optimal speed profiles — Jaramillo-Morales et al. (2020) demonstrated that optimized speed profiles for differential-drive mobile robots can achieve significant energy savings compared to trapezoidal profiles, by operating motors closer to their peak efficiency RPM during acceleration phases [16].
  • BLDC motor speed control for self-driving robots — Bae et al. (2020) presented sensorless speed estimation for in-wheel BLDC motors, showing improved low-speed control performance by compensating for Hall sensor lag—a relevant finding for AGVs operating at low wheel RPM [17].
  • Dual-PM motor design for AGV — Lin et al. (2020) proposed a novel direct-drive dual-PM motor specifically designed for electric AGVs, achieving high efficiency across a wide speed range by reducing torque ripple through split-tooth stator design [18].
  • Fuzzy speed control — Kodagoda et al. (2002, cited 250+ veces) developed fuzzy PD-PI controllers for AGV speed and steering, demonstrating that intelligent control can decouple speed from steering and maintain stable speed under varying load—a foundational result for AGV speed regulation [19].
  • Intelligent speed controllers comparison — Khan et al. (2025) compared PID, FLC, ANFIS, and MPC controllers for DC motor speed regulation in wheeled autonomous robots, providing quantitative guidance on controller selection for different speed-regulation requirements [20].

These studies collectively reinforce the principle that motor speed selection is not just a mechanical ratio calculation but must be coupled with control architecture design to achieve the speed regulation precision that AGV navigation systems demand.

Preguntas frecuentes: AGV Motor Speed and RPM Selection

What is the typical RPM range for AGV motors?

AGV motors typically operate in the 1,500–5,000 RPM rated speed range, with 2,500–3,500 RPM being the most common for warehouse AMRs and logistics AGVs (500–1,200 kg payload). Light AMRs (≤100 kg) may use motors up to 5,000 RPM, while heavy-duty AGVs (3,000+ kg) typically use 1,500–2,500 RPM motors with high gear ratios (15:1–30:1) [2][5].

How do I calculate the gear ratio from motor RPM to wheel speed?

The formula is: relación de transmisión (i) = motor RPM ÷ wheel RPM. Wheel RPM = (target speed in m/s × 60) ÷ (π × wheel diameter in meters). Por ejemplo, a 3,000 RPM motor with a 200 mm wheel at 1.5 m/s target speed: wheel RPM = (1.5 × 60) ÷ (pag × 0.2) = 143 RPM; ratio = 3,000 ÷ 143 ≈ 21:1 [3][7].

Should I use no-load speed or rated speed for gear ratio calculation?

Utilice siempre el velocidad nominal (speed at rated torque), not the no-load speed. DC and BLDC motors run 10–20% slower under load than at no load. Using no-load speed will produce a ratio that delivers 10–20% less output speed than intended under actual AGV load conditions [4][6].

What happens if my motor runs too slowly for the application?

If the motor operates far below its rated RPM (abajo 50% de clasificado), it enters a low-efficiency zone where: (1) energy consumption increases 15–35%, (2) ventiladores de refrigeración (if shaft-mounted) provide insufficient airflow, (3) current draw increases to maintain torque, accelerating thermal aging, y (4) battery runtime decreases proportionally [1][6].

How does IEC 60034-1 duty cycle classification affect motor speed selection?

CEI 60034-1 defines duty cycles S1–S10. For AGVs operating in S3 (intermittent) or S4 (intermittent with starting) modo, the motor can deliver 1.3–1.6× its S1-rated torque during active periods. This means you can select a motor with a lower S1-rated speed than a pure continuous-duty calculation would suggest—provided the RMS torque over the full cycle does not exceed the motor’s S1 rating [10][11].

Can I use a 48V motor on a 24V AGV battery?

Not recommended. A 48V motor on 24V will only reach approximately half its rated no-load speed, pushing the operating point into the low-efficiency zone. The motor will draw higher current to produce the same torque, increasing thermal load and reducing bearing life. Always match the motor’s rated voltage to the battery bus voltage [3].

Need a Custom AGV Motor Solution?

Selecting the right motor speed for your AGV platform requires balancing kinematics, gestión térmica, gearbox efficiency, and control architecture. GreenSky Power manufactures Motores BLDC, reductores planetarios, y custom electric motor solutions specifically optimized for AGV and AMR drive systems. Our engineering team can help you calculate the optimal motor RPM, relación de transmisión, and voltage platform for your specific payload, velocidad, y requisitos del ciclo de trabajo. Contáctenos for a technical consultation or request a product specification sheet for your AGV motor project.

For more AGV motor engineering resources, see our related guides:

Referencias

  1. Motor Jkong. “AGV无刷电机的转速和减速比应该如何匹配?” Disponible en: http://jkongmotor.cn/agvwushuadianjidezhuansuhejiansubiyinggairuhepipei.html
  2. Motor Jkong. “直流无刷电机在自动引导车中的实际应用.” Disponible en: https://www.jkongmotor.cn/zhiliuwushuadianjizaizidongyindaochezhongdeshijiyingyong.html
  3. HKT Robot (AGVMotor.com). “Servomotor sin escobillas para AGV: Especificaciones clave y guía de selección.” Disponible en: https://agvmotor.com/blogs/knowledge/brushless-servo-motor-for-agv
  4. SY Motor. “How to Select the Right Gear Reduction Ratio: A Practical Guide for Engineers and Procurement Teams.” Disponible en: https://www.symotor-hz.com/news/industry-news/how-to-select-the-right-gear-reduction-ratio-a-practical.html
  5. Energía del cielo verde. “Cómo elegir un motor para aplicaciones AGV: Guía de selección completa.” Disponible en: https://greensky-power.com/how-to-choose-a-motor-for-agv-applications/
  6. Maxon Precision Motors. “Motor Type Selection.Published via A3 Association for Advancing Automation. Disponible en: https://www.automate.org/tech-papers/motor-type-selection
  7. bicontroles (YK-Control). “AGV行走系统动力学计算与驱动选型指南:从整车阻力到舵轮电机及驱动器匹配.” Disponible en: https://www.bicontrols.com/news_detail/73.html
  8. Faulhaber Drive Systems. “Cálculos & Formulas for Brush DC Motors” (White Paper). Available via Qmed at: https://qmed.com/when-selecting-a-brush-dc-motor-for-an-file104689.html
  9. Grupo Maxon. “Motor Data and Simulation — Standard Tolerances.” Disponible en: https://support.maxongroup.com/hc/en-us/articles/360013761160-Motor-data-and-simulation
  10. Comisión Electrotécnica Internacional. CEI 60034-1:2022 — Máquinas eléctricas rotativas — Parte 1: Calificación y desempeño (Edición 15). Ginebra: CEI.
  11. HYX Geological Equipment. “Low-Speed Motor Parameter Encyclopedia: Comprehensive Technical Guide for Industrial Selection.” Disponible en: http://www.hyxgeo.com/article/179424572649472.html
  12. Asociación Nacional de Fabricantes Eléctricos. SIN MG 1-2021 — Motores y Generadores. Rosslyn, Virginia: NO HAY.
  13. The Engineering Toolbox. “Electric Motors — IEC and NEMA Standard Torques.” Disponible en: https://www.engineeringtoolbox.com/iec-nema-standards-torques-d_741.html
  14. Corporación Eléctrica Yaskawa. “Sigma-5 Servo Family — Product Catalog.” Disponible en: https://www.yaskawa.com/delegate/getAttachment?documentId=BL.Sigma-5.01
  15. Corporación Eléctrica Yaskawa. “Sigma-X Rotary Servomotors — Product Specifications.” Disponible en: https://yaskawa.co.uk/motion-control/sigma-x/sx-rotary-servomotors
  16. Jaramillo-Morales, M.F., Dogru, S., & Marques, L. (2020). “Generation of energy optimal speed profiles for a differential drive mobile robot with payload on straight trajectories.2020 IEEE International Symposium on Safety, Seguridad, and Rescue Robotics (SSRR), 136–141. DOI: 10.1109/SSRR50563.2020
  17. Bae, J., Lee, D.-H., & Cho, k. (2020). “Speed and Direction Control of Two In-wheel BLDC Motors for the Self-Driving Surveillance Robot.2020 IEEE International Conference on Mechatronics and Robotics Engineering (ICMRE). DOI: 10.1109/icmre49073.2020.9065011
  18. Lin, Q., Niu, S., Cai, F., Fu, W., & Shang, L. (2020). “Design and Optimization of a Novel Dual-PM Machine for Electric Vehicle Applications.Transacciones IEEE sobre tecnología vehicular, 69(12), 14391–14400. DOI: 10.1109/TVT.2020.3034573
  19. Kodagoda, K.R.S., Wijesoma, W.S., & Teoh, E.K. (2002). “Fuzzy speed and steering control of an AGV.IEEE Transactions on Control Systems Technology, 10(1), 112–120. DOI: 10.1109/87.974981
  20. Khan, H., Namazi, H., & Lenort, R. (2025). “Advanced Intelligent Controllers Design and Simulation Analysis for Optimizing Speed Control of Autonomous Systems.IEEEX. Disponible en: https://ieeexplore.ieee.org/document/11370730

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