SANMOTION PB series AC power input stepper system

SANMOTION PB series AC power input stepper system

Background and positioning of product research and development

Research and development intention: The SANMOTION PB series was developed by Sanyo Electric, with the core purpose of filling the market gap between open-loop stepper systems and AC servo systems, fully utilizing the low-speed and high torque characteristics of stepper motors, and adapting to the positioning equipment of conveyor systems and short stroke high hit rate application scenarios.

Market demand: With the high-speed and high reliability development of stepper systems, as well as the increasing demand for servo system alternatives, there is a surge in demand for cost sensitive, high torque, and high-performance drive solutions in the market, which has become an opportunity for the research and development of this product.

Product Core: The SANMOTION PB series, which is an AC power input type, will be introduced from three aspects: architecture, specifications, and features.

Overall architecture and core specifications of the product

The system consists of an amplifier and a stepper motor. A single amplifier can be adapted to a full range of 5 motors, and the interface and power supply have multi specification compatibility. The core specifications are clearly displayed in a table.

（1） Amplifier core specifications (model: PB4A002 R30/P30)

Specific specifications, key numbers/characteristics of the project

Control Method: Sine Wave PWM Control Core Control Algorithm

Power input single-phase AC100/115V; Single/three-phase AC200/230V voltage allowable fluctuation:+10%, -15%

Exterior structure tray type, external dimensions H150 × W42 × D120 (mm) Weight: approximately 0.64kg

4 interface combination models: pulse chain input+RS-485 half duplex/parallel I/O (R-type programmable)

The maximum positioning resolution of 3200P/R is achieved through electronic gear function

Suitable motor speed 42/60mm square motor: 0-4500min ⁻¹;; 86mm square motor: 0-4000min ⁻¹, graded according to motor size

Speed command resolution 1min ⁻¹ high-precision speed adjustment

High integration of built-in functions such as brake control, regeneration control, automatic micro S-shape, positioning, inching, zeroing, forced operation, and modular computing

Operation functions: digital manipulator: gain setting, motor combination, resolution adjustment, jog, teaching, pulse chain input mode setting, user-friendly operation

Protection functions: motor overheating, amplifier overheating, power supply voltage error, sensor disconnection, overspeed, RST action, CPU error, EEPROM error, PAM voltage error, overload, overcurrent detection, totaling more than ten protections, with high safety

Input/output signal pulse input (1/2 input method), 8-channel universal input, 7-channel universal output (R30); 2-channel universal input, 2-channel universal output (P30) including core signals such as ALM, In Position, HOME END, etc

（2） Core specifications of motors (5 models, divided into 42/60/86mm square)

Motor model PBM423FXK20 PBM603FXK20 PBM604FXK20 PBM861FXK20 PBM862FXK20

Maximum stalling torque (N · m) 0.39 1.3 1.9 3.5 6.6

Rotor inertia (kg cm ²) 0.056 0.4 0.84 1.48 3

Allowable axial load (N) 9.8 14.7 14.7 60

Allowable radial load (N) 49 167 167 200

Motor weight (kg) 0.35 0.85 1.42 1.9 3.1

Sensor specifications: Optical incremental encoder, 4000P/R, A/B/C channels/phase origin signal, all series with unified specifications

Optional brake ○○○ XXX

Low backlash/harmonic gear

Note: ○ indicates support, X indicates no support.  

Core product features (five key upgrades)

This series of products has completed multiple core innovations on the basis of traditional stepper systems, achieving performance leaps in five aspects: heat generation, torque, accuracy, synchronization, and ease of use, which are the core competitive advantages.

Significant reduction in motor heating (80% decrease)

Traditional problem: Open loop stepper systems use constant current power supply. Although the traditional AC PB series adopts proportional integral control, the current ripple of PWM control is large, resulting in severe iron loss and heating of multi pole motors such as stepper motors.

Innovative solution: Develop a new current ripple suppression control method that does not lose responsiveness, providing only the required current based on the load operating state, significantly reducing motor heating.

Actual effect: The 42mm square motor reduces heating by 80% compared to traditional products, solving the core heating pain point of stepper motors.

Significant increase in high-speed torque, achieving low power consumption

Traditional problem: Traditional products suffer from heating issues in PWM systems, and voltage reduction circuits limit the voltage applied to the motor, resulting in a decrease in current time constant and insufficient torque during high-speed operation.

Innovative solution: ① By optimizing the PWM control system mentioned above, the voltage reduction circuit is eliminated to increase the applied voltage to the motor; ② Optimize the specifications of motor windings; ③ Improve motor efficiency.

Actual effect: Achieving the dual advantages of high torque and low power consumption, while eliminating the voltage reduction circuit reduces the number of components and lowers production and maintenance costs.

Significant improvement in positioning accuracy (repeatability), unaffected by load

Traditional problem: Traditional stepper motors use closed-loop control when moving, and switch to open-loop self-sustaining torque control when stopping. The positioning accuracy is compromised when there is a load present; If the entire loop is closed, micro vibrations will occur, losing the advantage of complete stopping.

Innovative solution: ① Increase the encoder resolution from 500P/R to 4000P/R (up to 16000P/R after 4x), which can detect small positional deviation angles when stopping; ② Develop exclusive position compensation function, balancing the advantages of positioning accuracy and complete stopping.

Actual effect: The positioning accuracy (especially repeatability) has been greatly improved, and it is not affected by load conditions, solving the core accuracy pain point of stepper motor positioning.

Improved command synchronization and significantly reduced position deviation

Traditional problem: Although proportional integral control can avoid speed fluctuations caused by open-loop stepping loss and resonance, it has poor command synchronization (large position deviation) and cannot adapt to equipment sensitive to position deviation (such as labeling equipment).

Innovative solution: ① Add feedforward (FF) function in the positioning loop to significantly reduce position deviation; ② Optimize the deviation clearing operation of external signals and adapt to devices that require manual deviation clearing.

Actual effect: The position deviation is significantly reduced, and the product can be adapted to application scenarios such as labeling equipment that require high command synchronization, expanding the scope of application.

Humanized features come standard, greatly improving usability. The product integrates multiple user-friendly functions without the need for external accessories, making operation and maintenance more convenient

Standard digital operator to improve the convenience of parameter setting and testing operation;

The R-type model supports online/offline teaching functions only through digital operators;

Adopting a 7SEG LED display screen for quick confirmation of alarm content and amplifier status;

The amplifier has built-in brake control function, without the need for external brake power supply or relay contacts;

The amplifier is equipped with a dedicated regeneration control function, eliminating the need for an external regeneration unit;

The pulse input mode also comes standard with a forced operation function, compatible with the electrification transformation of pneumatic equipment.

Product Conclusion and Future Planning

Existing achievements: Through performance improvement and feature addition, the SANMOTION PB series has achieved multi scenario adaptation, becoming a cost-effective solution between open-loop stepper and servo systems, meeting the comprehensive market demand for cost, torque, and performance.

Future plan: ① Further enhance the characteristics of the motor itself, such as eliminating magnetic noise of stepper motors and improving power ratio; ② Taking into account environmental factors and continuously optimizing product performance; ③ Based on the existing foundation, expand the lineup of SANMOTION PB series products to cover more application scenarios.