差動駆動 AGV とデュアル ドライブ AGV: 移動ロボットのステアリングの技術比較
A specification-level comparison of differential drive (dual motor) and dual steering-wheel AGVs — covering steering kinematics, モータートルク, 効率基準, and a payload-based selection framework for AGV and AMR engineers.
簡単な回答
あ differential drive AGV uses two fixed drive wheels, each with its own motor, and steers by creating a speed difference between them — it follows curved paths and can pivot in place but cannot move sideways. あ dual drive AGV (two steering wheels / dual omnidirectional drive) uses two integrated steer-drive modules that actively rotate the wheel for traction, enabling true omnidirectional motion including lateral translation. 選ぶ ディファレンシャルドライブ for cost-sensitive, open-route transport up to ~1 ton; choose dual drive for narrow aisles, high-density docking, or 1–3 ton loads where omnidirectional precision justifies the higher cost. Both architectures share the same BLDC/servo motor base and should target IEC 60034-30-1 IE3/IE4 efficiency.
What Is a Differential Drive and a Dual Drive AGV?
AGV steering architecture determines how the vehicle generates motion and how precisely it can follow a path. The two most common battery-powered AGV drive layouts are the ディファレンシャルドライブ (sometimes called “dual motor AGV”) そして dual drive (dual steering-wheel) 構成.
Differential Drive AGV (Dual Motor AGV)
A differential drive AGV carries two independently controlled drive wheels (left and right) mounted along the vehicle centerline, supported by one or more passive caster wheels. Each drive wheel has its own BLDC or servo motor plus gearbox. Steering is produced entirely by the speed difference between the two wheels — there is no dedicated steering motor or steerable wheel.
- Kinematics: linear velocity
v = (vL + vR) / 2; 角速度ω = (vR − vL) / L, どこLis the wheelbase. - Zero-radius turn: when
vL = −vR, the AGV spins about its center. - 限界: the trajectory is always an arc — pure lateral (sideways) motion is impossible.
Dual Drive AGV (Dual Steering Wheel / Omnidirectional)
A dual drive AGV mounts two integrated steer-drive modules (typically front-and-rear, or diagonal). Each module combines a drive motor, a steering motor, a reduction gearbox, and an encoder in one compact unit. Because the wheel orientation is actively controlled, the AGV achieves omnidirectional motion: forward, reverse, in-place rotation, と lateral translation.
- コントロール: dual closed-loop — steering angle feedback + wheel speed feedback.
- アドバンテージ: true lateral movement and higher docking precision in dense aisles.
- Trade-off: higher component count (4 motors vs 2), greater cost, and stricter floor-flatness requirements.
| 側面 | ディファレンシャルドライブ (Dual Motor) | Dual Drive (Dual Steering Wheel) |
|---|---|---|
| Drive actuators | 2 drive wheels, 2 モーター | 2 steer-drive modules, 4 モーター (2 ドライブ + 2 操縦する) |
| 操舵方法 | Speed difference between wheels | Active wheel orientation |
| Lateral (sideways) motion | Not possible | Supported |
| In-place rotation | はい (zero radius) | はい (zero radius) |
| Typical payload | ≤ 1,000 kg | 1,000 – 3,000 kg |
| Positioning precision | 中くらい (error accumulates over distance) | 高い (dual closed-loop) |
| Control complexity | 低い | 高い |
| 相対コスト | 低い | 高い |
| Best floor condition | スムーズ, sealed | Very flat, suspended modules preferred |
How Differential and Dual Drive AGVs Work — Step by Step
Differential Drive Power Flow
- Battery release: の 24/48 V DC pack delivers current to the two motor controllers.
- Independent commutation: each controller performs FOC on its own BLDC/servo motor based on encoder/Hall feedback.
- Speed difference generation: the motion controller commands
vLとvR; unequal speeds create the turn. - Gearbox torque multiplication: each planetary reducer scales motor torque to wheel torque.
- Wheel-to-floor traction: both wheels push against the floor; the net force vector curves the path.
- Odometry feedback: wheel encoders feed dead-reckoning; drift is corrected by lidar/QR navigation.
Dual Drive Power Flow
- Battery release: DC bus feeds four axes (2 ドライブ + 2 steering).
- Steering orientation: steering motors rotate each module to the target angle via a high-resolution encoder.
- Drive commutation: drive motors produce traction along the oriented wheel axis.
- Vector synthesis: the controller solves inverse kinematics to combine the two module forces into the desired body motion (including lateral).
- ギアボックス + wheel traction: same as differential, but forces can be decomposed in any direction.
- Dual closed-loop correction: steering-angle and wheel-speed loops keep the body on the planned trajectory.
機能比較表
| パラメーター | Differential Drive AGV | Dual Drive AGV |
|---|---|---|
| Number of motors | 2 (one per wheel) | 4 (2 ドライブ + 2 操縦する) |
| Steering authority | Indirect (via speed Δ) | 直接 (wheel angle) |
| Min. turning radius | 0 (pivot) | 0 (pivot) |
| Lateral translation | いいえ | はい |
| Path following on uneven floor | Sensitive to slip/drift | 安定した (active correction) |
| Encoder requirement | 1,000–2,500 PPR / 17-bit | 17–24 bit absolute + steering encoder |
| Thermal duty (IEC) | S3 / S4 | S3 / S4 |
| システム効率 (end-to-end) | 80–88% | 78–86% (more losses) |
| Maintenance points | Fewer (2 modules) | More (4 モーター + steering gears) |
| Typical applications | Light AMR, Kiva-style, サービスロボット | High-density warehouse, heavy latent AGV, parking robots |
エンジニアリングデータ: 効率, 温度制限, とトルクの計算式
IEC 60034-1 Duty Cycle Mapping
AGV drive motors operate in intermittent, start-stop profiles — never continuous S1. Select the duty type that matches the task:
| IEC Duty | Profile | AGVの関連性 |
|---|---|---|
| S1 | 継続的, 定荷重 | Rare (conveyor loops only) |
| S3 | Intermittent periodic, starting neglected | Common pick-and-place AMR (S3-40%) |
| S4 | Intermittent with starting | Frequent start/stop transport |
| S5 | Intermittent with braking | Rapid positioning, 回生ブレーキ |
| S6 | Continuous with load/unload | Continuous roam with idle waits |
IEC 60034-30-1 / MGはありません 1 効率クラス
| IECクラス | NEMA相当品 | Typical AGV drive efficiency |
|---|---|---|
| IE1 | 標準 | Phased out — not recommended |
| IE2 | 高効率 | Legacy brushed only |
| IE3 | プレミアム | Minimum for new BLDC/servo drives |
| IE4 | スーパープレミアム | Target for 2027+ コンプライアンス |
| IE5 | — | 新興 (VFD-assisted) |
Core Torque Formulas
aの ディファレンシャルドライブ with two drive wheels sharing the load, the torque per motor is:
どこ F_traction = total resistance (rolling + slope + 加速度), r_wheel = wheel radius, η = gearbox efficiency (~0.9/stage). aの dual drive module, each steer-drive carries roughly half the body load but must also react steering torque:
Turning-radius kinematics for differential drive:
For a dual steering wheel, the minimum radius is set by module geometry:
作業例: あ 500 kg AGV (total mass) に 3% slope at 1.5 m/s with 0.2 m wheels. F_rolling = 0.015 × 500 × 9.81 = 73.6 N; F_slope = 500 × 9.81 ×罪(1.72°) = 147.6 N; F_acc = 500 × 0.5 = 250 N. F_traction = 471 N. Per differential motor: T = (471 × 0.1) / (2 × 0.9) = 26.2 N・m peak — comfortably within a Maxon MW500 (23.7 N·m continuous, 70 N·m peak at 48 V).
Manufacturer Reference Data
| サプライヤー | 製品 / family | Key spec for AGV drive |
|---|---|---|
| マクソン | MW500 wheel drive | ≤500 kg payload; 11.4–23.7N・m連続; 30–48V; IP54; 1024 cpt encoder |
| マクソン | IDX 56 | 471–794mNm; 24/48 V; IP65; integrated EPOS4 controller |
| ファールハーバー | デュアルギア (BX4 + GPT) | Ø32 mm; 1.1 N・m継続. / 7 N·m max; ≤0.6° backlash; −30 to 120 ℃ |
| 安川 | シグマ-7 SGM7D | 1.3–240N・m; 3.1 kHz speed loop; 24-ビットエンコーダ; 350% 過負荷 3 ～ 5 秒; ワンハンドレッドシル3 |
| SKF | E2 deep-groove bearing | 30–50% lower friction vs standard; extends motor life & 効率 |
Best Applications for Each Drive Type
| シナリオ | 推奨ドライブ | 理由 |
|---|---|---|
| Goods-to-person picking (Kiva-style) | ディファレンシャル | Fixed routes, light load, コスト重視の |
| Restaurant / hotel service robots | ディファレンシャル | Low load, open areas, 予算に敏感な |
| Narrow-aisle high-density warehouse | Dual drive | Lateral translation + in-place rotation |
| Heavy latent AGV (1–3 t) | Dual drive | Higher payload, precise docking |
| Parking robots | Dual drive | Omnidirectional, tight maneuvering |
| Long-haul line-side transport | ディファレンシャル | Stable at speed, simpler, cheaper |
Step-by-Step Selection Process
- Define the payload and total mass (vehicle + 負荷). Above 1 t, bias toward dual drive.
- Map the route geometry. Fixed open paths → differential; narrow aisles / lateral docking → dual drive.
- Calculate traction force (rolling + slope + 加速度) per the formulas above.
- Solve motor torque. ディファレンシャル: divide by 2 モーター; dual drive: divide by 2 modules + steering torque.
- Select gearbox ratio to land motor speed in the 2,000–4,000 RPM sweet spot at target wheel RPM.
- Verify duty cycle against IEC S3/S4 and thermal class (typically F, 155 ℃).
- Confirm feedback & 安全性. Differential needs 1,000+ PPR エンコーダ; dual drive needs 17–24 bit absolute + steering encoder + STO (SIL3).
よくあるエンジニアリングの間違い
| 間違い | 結果 | 正しいアプローチ |
|---|---|---|
| Sizing motor on peak torque only | Thermal trip under continuous load | Verify continuous torque vs RMS over the duty cycle |
| Using differential drive on uneven floors | Wheel slip, odometry drift | Specify suspended modules or move to dual drive |
| Underestimating steering torque in dual drive | Sluggish orientation, docking error | Add T_steer term; size steering motor separately |
| Ignoring gearbox backlash | Position jitter at low speed | Use planetary ≤15 arc-min; Faulhaber DualGear ≤0.6° |
| Mismatched encoder resolution | Poor speed regulation | Differential ≥1,000 PPR; dual drive ≥17 bit absolute |
| Skipping efficiency class check | Non-compliant with IE3/IE4 rules | Target IEC 60034-30-1 IE3以上, IE4 preferred |
| Over-specifying for light carts | Wasted cost | ディファレンシャル + BLDC suffices under 300 kg |
| No regenerative braking design | Wasted battery, 熱 | Use S5 duty profile with energy recovery |
トラブルシューティング表
| 問題 | 原因 | 解決 | Applies to |
|---|---|---|---|
| AGV drifts off path | Wheel slip / floor unevenness | Add suspension; recalibrate encoder; switch to dual drive | ディファレンシャル |
| Motor overheats in service | 連続トルク > 評価された | Re-size motor or improve cooling; check S3/S4 rating | Both |
| Poor docking accuracy | Low encoder resolution | Upgrade to 17–24 bit absolute encoder | Dual drive |
| One wheel lifts (4-wheel) | Chassis flex / floor | Add floating suspension to steer modules | Dual drive |
| Excessive noise at low speed | Gearbox backlash | Use low-backlash planetary; check Faulhaber DualGear | Both |
| Steering lags command | Undersized steering motor | Increase steering torque; raise loop bandwidth | Dual drive |
| バッテリーの消耗が早い | Low-efficiency motors | Move to IE3/IE4 BLDC; enable regen | Both |
| Can’t translate sideways | Differential architecture limit | Re-architect to dual steering wheel | ディファレンシャル |
| ベアリングの早期故障 | Contamination / 過負荷 | Use SKF E2 sealed bearings; verify load rating | Both |
| Position error accumulates | Open-loop odometry only | Fuse lidar/QR; close steering loop | ディファレンシャル |
よくある質問
What is the main difference between differential drive and dual drive AGVs?
A differential drive AGV uses two fixed drive wheels and steers by a speed difference between them, following curved paths with no lateral movement. A dual drive AGV uses two integrated steer-drive modules that actively orient the wheel, enabling true omnidirectional motion including lateral translation.
Is a differential drive AGV the same as a dual motor AGV?
はい. A differential drive system uses two independently controlled drive motors (one per wheel), それで “dual motor AGV” と “differential drive AGV” describe the same architecture. Both wheels share traction load and the speed differential produces steering.
Which AGV drive type is better for narrow warehouse aisles?
Dual drive AGVs excel in narrow aisles because they can translate laterally and rotate in place without a turning radius. Differential drive AGVs are better for open, fixed-route transport where cost is the priority and lateral movement is not required.
How much load can a differential drive AGV handle?
Typical differential drive AGVs handle up to 1 ton (1,000 kg) of payload. Above this, traction loss on uneven floors and wheel-slip sensitivity grow. For 1–3 ton loads, dual steering wheel or four-wheel steering configurations are preferred.
What motor efficiency should AGV drive motors meet?
AGV drive motors should target IEC 60034-30-1 IE3 or IE4 efficiency. BLDC drive motors reach 85–92% system efficiency; servo-grade BLDC reaches 90–95%. The duty cycle is typically IEC S3 or S4 (intermittent with starts/braking), not continuous S1.
Can a differential drive AGV achieve in-place rotation?
はい. When the left and right drive wheels spin at equal speed in opposite directions, the AGV rotates about its center with a theoretical turning radius of zero. This zero-radius pivot is a key advantage of differential drive for confined spaces.
Why Choose GreenSky Power for Your AGV Drive Motors?
GreenSky Power has designed and manufactured motion control solutions for AGV and AMR builders since 2011, serving OEM customers in over 50 国. For differential and dual drive AGV projects, 私たちが提供します:
- Both architectures from one source — BLDC, サーボ, and geared motor platforms deploy in differential (dual motor) or dual steering-wheel configurations. 私たちのを参照してください gear motor vs direct drive guide.
- Engineering calculation support — send mass, スピード, 加速度, slope, and wheel diameter; we return a torque/ratio datasheet. まずは私たちのものから始めましょう AGV motor selection guide.
- 規格への準拠 — all motors tested per IEC 60034-1 with dynamometer reports; thermal class F (155 ℃); IE3/IE4 efficiency.
- Low-backlash gearboxes — planetary reducers from 5 arc-min for precise differential and dual-drive systems.
- Closed-loop feedback — 1,000–4,096 PPR encoders or 17–24 bit absolute, matched to your navigation requirement.
- OEM supply chain — see our OEM製造ガイド と Europe supply program.
Related reading: AGV ドライブ システムの仕組み · Components of an AGV Vehicle · Best Motor Types for AGVs · AGV Torque Calculation · AGV Speed & RPM Guide · AGV Efficiency & Battery Runtime · BLDC vs Servo for AGVs · Types of Warehouse AGVs · AGVとは? · AGV vs AMR.
参照
- 国際電気標準会議. IEC 60034-1:2022 — 回転電機 — 部品 1: 評価と性能 (Edition 15). Geneva: IEC. — https://webstore.iec.ch/publication/68321
- 国際電気標準会議. IEC 60034-30-1:2014 — Efficiency classes of line-operated AC motors. Geneva: IEC. — https://webstore.iec.ch/publication/6549
- 全国電気製造者協会. MGはありません 1-2021 — モーターと発電機. Rosslyn, VA: ありません. — https://www.nema.org/standards/view/mg-1-motors-and-generators
- 私たち. エネルギー省. 10 CFRパート 431 — Energy Efficiency Program for Commercial and Industrial Equipment: 電動モーター. — https://www.ecfr.gov/current/title-10/chapter-II/subchapter-D/part-431
- 国際エネルギー機関. エネルギー効率 2025 (motor systems chapter). Paris: IEA. — https://www.iea.org/reports/energy-efficiency-2025
- SKFグループ. エネルギー効率が高い (E2) 電動モーター用深溝玉軸受 (offer sheet). — https://www.skf.com/group/products/bearings-units-housings/ball-bearings/deep-groove-ball-bearings/energy-efficient-bearings
- シーメンスAG. Digital transformation at the Bad Neustadt Electric Motor Factory (Digital Twin, IT/OT convergence). — https://www.siemens.com/global/en/company/about/businesses/digital-industries/bad-neustadt.html
- マクソングループ. MW500 wheel drive for AGV and AMR — product recommendation. — https://www.maxongroup.com/maxon/products/complete-systems/wheel-drive
- ファールハーバー. DualGear — dual drive system for logistics (BX4 + GPT). — https://www.faulhaber.com/lp/faulhaber-dualgear/
- 株式会社安川電機. SIGMA-7 Servo Systems — Direct Drive Servomotors (SGM7D/F/E). — https://www.yaskawa.com/products/motion/drives/servo/sigma-7/
