Application of the Xinshida ET6L Inverter in Warehousing and Material Handling in the Logistics Industry
2025-06-05
Application of the Xinshida ET6L Inverter in Warehousing and Material Handling in the Logistics Industry
Project Background
The allure of Chinese manufacturing lies in its continuous breakthroughs in technological barriers throughout its ongoing development—and often, it surpasses its predecessors. The variable-frequency drive, hailed as the cornerstone of modern industry, was once a field in which China lagged behind Western countries by two decades. Yet today, Chinese-made variable-frequency drives have successfully overcome their past technological limitations and achieved remarkable accomplishments.
Take the logistics industry as an example: Although foreign brands boast mature technology and clear first-mover advantages as well as strong brand recognition, domestically produced variable-frequency drives (VFDs) are steadily expanding their market share in the logistics sector year after year, demonstrating their competitive strength. Next, using the application of Xintida VFDs in stacker cranes and elevators as an illustration, we’ll explore how domestic VFDs have successfully carved out a niche for themselves in the logistics market despite the established advantages held by foreign brands.
Customer needs
It can precisely control the speed and position of cargo movement. When used in automated storage and retrieval systems (AS/RS) lifts, it prevents cargo from getting stuck or causing wheel jams due to positional changes caused by cargo entering or exiting the cabin. While ensuring smooth cargo transport, it achieves the shortest possible travel time to the target location. It also effectively suppresses load sway, enhancing both efficiency and safety, and is easy to debug.
Xinshida Solution
Technological Advantages
1. Dual-loop control technology
Simultaneously employing both velocity and position feedback loops, the velocity loop is used for rapid, real-time acquisition of the motor speed, while the position loop captures the absolute mechanical positioning. This constitutes a dual-loop control system that, through an efficient algorithm, achieves stable and balanced current-torque control while maximizing motor efficiency.
2. Dynamic Leveling Function
Based on the existing mechanical transmission and motor configuration, and leveraging dual-loop control technology that combines a speed loop and a position loop, while simultaneously activating the software feature for dynamic leveling, the system relies on its powerful zero-speed hovering capability to ensure the stability of the four-way in-and-out lift for onboard cargo.
3. Direct Stop Algorithm
The dynamic programming position curve ensures the shortest possible travel time to the target position. The position curve undergoes a second-order FIR filtering to generate smooth acceleration, guaranteeing stable cargo transportation. Upon reaching the destination, position calibration is performed in conjunction with level-limit switches, ensuring that the final leveling accuracy is within ±1 mm.
4. Anti-sway function
Due to the pendulum system formed by the inertia of the suspended load and the suspension cable, the load will swing during operation—especially during the acceleration and deceleration phases. Load swinging during crane movement is a very serious and common issue that can significantly impair operational efficiency. The anti-swing function employs a triple mechanism to effectively suppress oscillations, thereby preventing the load from swinging when the trolley or hoist is accelerating or decelerating.
5. Host computer software + servo control module
Parameter settings for the frequency inverter are critical to its proper operation. Incorrect settings not only may prevent the inverter from functioning normally but, in some cases, could even damage the inverter itself. Host computer software: A customized commissioning wizard tailored specifically for the logistics industry, guiding customers through on-site debugging procedures; dynamic self-learning capability that eliminates the need to input mechanical gear ratios and wheel diameters, automatically calculating the rated linear speed; servo control blocks: Pre-packaged servo control blocks designed according to users’ programming habits, providing ready-to-use references for customers. This approach saves time during commissioning and reduces programming effort. When users replace their existing ET6L frequency inverter with a new one, they simply need to drag the variables from the original program onto the corresponding pins of the control block and make minor program adjustments to enable the ET6L inverter to operate in position-control mode.
The intelligent, flexible ET6L series frequency converters—specifically designed for the logistics industry—have not only overcome the five technical bottlenecks mentioned above but, based on actual application data and waveform analysis of the converter’s operation, have also reached an advanced level within the industry.
Technological Advantages
The stacker crane is the core equipment of an automated stereoscopic warehouse. Its primary function is to shuttle back and forth between aisles in the stereoscopic warehouse, performing coordinated movements—including horizontal reciprocating linear motion, vertical lifting, and left-right extension of the fork—so as to automatically store goods into designated storage locations on the shelves or retrieve goods from those locations, thereby enabling automated inbound and outbound operations in the automated stereoscopic warehouse.
1. Case 1: Lithium Battery Project of a Subsidiary Under a State-Owned Enterprise in the Logistics Industry
● User requirements
Precisely control the speed and position of cargo movement.
● Project Results
Finally, on-site measurements—covering the normal handling of 500 kg test objects and multi-layer handling of 1-ton full-load test objects—successfully addressed the phenomenon-level issue.
● Xindashida Solutions
When walking, the enhanced laser ranging SSI signal is directly fed into the inverter, which uses its internal control system to manage position and autonomously plan the optimal velocity profile. With a dual closed-loop control system—both speed and position are regulated—target positions are precisely reached without any creep distance.
2. Case 2: A Super Factory of One of the Top 3 Integrators in the Logistics Industry
● User requirements
Precisely control the speed and position of cargo movement.
● Project Results
Finally, on-site measurements were conducted, confirming the normal handling and retrieval of 500 kg test objects as well as the retrieval and handling of a single layer of 1-ton full-load test objects.
● Xindashida Solutions
The stacker crane’s travel motion employs open-loop vector control and laser ranging; during lifting, it uses closed-loop vector control and barcode-based ranging; for fork movement, it operates under open-loop control with absolute encoder-based ranging.
Elevator Application
The lift can operate on fixed tracks and uses electric or hydraulic systems to lift and transport goods. Lifts are commonly used in high-rise buildings, warehouses, logistics centers, and other similar facilities to facilitate the efficient movement of goods. Unlike stackers, lifts are primarily designed for vertical transportation rather than shuttling between aisles.
1. Case 1: Application Solution for Heavy-Duty Hoists
● User requirements
High positioning accuracy, cost-effective control, and smooth layer changes without jamming the chassis.
● Project Results
Finally, on-site measurements were conducted and passed, demonstrating normal handling of 500 kg test objects during production and multi-layer handling of 1-ton full-load test objects. The system has been accepted and has been in normal operation for one year since its launch.
● Xindashida Solutions
The motor uses a synchronous traction machine, achieving a full-load capacity of 1 ton, an operating speed of 1 m/s, and an acceleration/deceleration rate of 0.3 m/s². The speed-loop traction machine is equipped with a sine-cosine encoder, and position feedback is provided via magnetic grating scales communicating with the inverter through CAN bus, ensuring a positioning accuracy of ±1 mm. This traction-machine solution features lower costs and more stable control. When the dynamic leveling function is enabled, it effectively prevents the chassis from getting stuck during four-way car cargo transfers between floors.
2. Case Study 2: Application Solution for High-Speed Elevators
● User requirements
High positioning accuracy, seamless layer changes without jamming the chassis, and enhanced safety.
● Project Results
Finally, the system passed the 30 kg test object’s normal production handling and the multi-layer cyclic test with a 50 kg fully loaded test object. All performance indicators were verified to meet and even exceed those of the original system, successfully replacing the original Lenze system and gaining customer approval.
● Xindashida Solutions
SEW replacement for high-speed logistics elevators: when fully loaded at 50 kg × 2, the operating speed is 2 m/s, with an acceleration and deceleration rate of 2 m/s². After enabling the dynamic leveling function, it effectively prevents the chassis from getting stuck during four-way vehicle cargo transfers between floors. Positioning accuracy is ±1 mm. STEP brake power supply (integrating brake power supply and switching power supply): includes an enable control terminal, eliminating the need for a contactor and ensuring silent operation. It automatically switches between boost voltage and holding voltage, provides input and output short-circuit protection, and features fault output signaling.
Associated products
ET6L Heavy-Duty High-Performance Inverter
Project Results
In the above-mentioned projects, Xindasheng frequency converters have all met user requirements and successfully achieved the domestic substitution of imported frequency converters.
