Market Application Background
With the deepening of intelligent transformation in the manufacturing industry, the handling of small materials in fields such as 3C electronics, PCB, food packaging, pharmaceuticals, cosmetics, and auto parts is undergoing a transformation in production models. Traditional mechanical vibratory feeder feeding and single tray/labeling methods can no longer meet the current market demand for high-precision, high-efficiency, and flexible production. The industry is rapidly transforming from large-volume, single-product production to multi-product, small-batch, customized production models.
Introduction to Multi-nozzle Vision-Based Loading and Unloading Process:
The material is placed in a vibrating tray and vibrated to disperse. A third-party vision system performs initial identification and matching of the material in the tray, generating OK material coordinates. The machine then moves synchronously to the OK material coordinates, where multiple suction nozzles adsorb the material. During the process of placing the material into the tray, a visual scanning function corrects any misalignment, ensuring the material is properly positioned. Currently, the types of materials that loading and unloading systems need to handle are becoming increasingly complex, including packaging materials with smart labels such as QR codes, barcodes, and anti-counterfeiting codes, as well as various precision electronic components and miniature hardware accessories. This diverse material handling demand places higher requirements on visual recognition accuracy, mechanical positioning accuracy, and system flexibility.
▲ Common material loading and unloading diagrams ▲
Common visual loading and unloading solutions on the market:
During material handling, the grippers or suction cups of a robotic arm can cause slight positional shifts in the material, affecting overall loading accuracy. To avoid this, industrial cameras are typically used to capture the position of the gripped or sucked material during workpiece movement and to perform position correction. Currently, most loading/unloading systems without vision-based camera capture employ a "computer + machine vision + PLC + touchscreen" solution, and position correction only uses a fixed-point shooting method, meaning the equipment stops at the capture point to allow the camera to take a picture before resuming operation. This approach increases the waiting time during movement, reduces the efficiency of the loading/unloading process, and severely impacts production capacity.
▲ V/t diagram of the equipment when using the traditional fixed-shot method ▲
Positive motion technology multi-nozzle vision loading and unloading solution:
Addressing the pain points of traditional solutions, Zheng Motion Technology has launched a multi-nozzle vision loading and unloading solution based on the ultra-high-speed PCIe EtherCAT motion control card PCIE464M.
When the motion mechanism reaches the preset shooting area, the motion control card precisely triggers the industrial camera to perform multi-position aerial shooting operations via high-speed digital I/O ports. Combined with third-party vision, parallel image acquisition and feature recognition at multiple nozzle stations are completed in a short time, and sub-pixel-level positioning data is fed back to the motion controller in real time. The system can simultaneously perform multi-axis position compensation and angle correction, enabling high-speed continuous aerial shooting operations. This solution improves overall efficiency by more than 12% compared to traditional fixed-position shooting.
▲ V/t diagram of the equipment when using a positive motion flight shooting scheme ▲
01. Solution for multi-nozzle loading and unloading using a PCIE4 64M motion control card
Design of a multi-nozzle vision-based loading and unloading solution for positive motion
1. 16DI: Connects to origin, limit, and other sensors, as well as switch signals, encoders, etc.
2. 16DO: High-speed output port for connecting to the hard trigger input of industrial cameras and dispensing valves;
3. EtherCAT Interface: Connects to an EtherCAT bus driver to control the movement of other axes; also expands the EtherCAT IO module, with EtherCAT cycle times as fast as 125µs;
4. Eight-channel single-ended pulse output: connects to a pulse driver;
5. RS232 communication interface: connected to the light source controller;
6. Ethernet interface: Gigabit Ethernet port, for connecting area scan cameras that support the Gigabit protocol to achieve visual positioning and correction applications.
Motion control technology implementation
The PCIe 464M motion control card sends commands to the driver via the EtherCAT bus, driving the motor to perform motion control tasks. The system provides real-time feedback of the motor position (MPOS) through an encoder or linear encoder, and combines this with motion control algorithms to achieve precise position control. This triggers the camera to accurately capture images at the target location, ensuring image acquisition accuracy and synchronization under high-speed motion, meeting the precise positioning requirements of high-speed aerial photography scenarios.
Solution Application Action Flow
01. Visual positioning of material trays
The camera takes pictures of the material in the vibratory feeder for rough positioning, and combines this with third-party vision calculations to determine the coordinates of the gripping position and plan the gripping path;
02. Material handling and grabbing mechanism
Based on the calculated position, the suction nozzles on the motion axis move to the correct position, and multiple suction nozzles grip the material.
03. Multi-position visual aerial photography with lower camera
The captured material moves to the area where the lower camera takes pictures, and the motion control card precisely outputs/hardware position comparison outputs to trigger the camera to perform visual capture of the material coming from multiple suction nozzles;
▲ Multi-position aerial photography parameter settings ▲
04. Multi-position positioning and correction
Combine third-party vision analysis to perform visual analysis and processing on the photographed material images, and perform positional correction and adjustment;
05. Discharge material
During the movement to the unloading position, angle and position compensation and correction are performed, and then the material is unloaded from multiple positions after reaching the correct target position;
06. Return to loading position
After the material is unloaded, it returns to the loading position and prepares for the next grab, repeating the cycle in turn.
Multi-nozzle loading and unloading application process
Solution Application Advantages
1. Compatible with operating systems such as Windows XP/7/10/11 and Linux, offering wide applicability;
2. A unified and open API function interface allows users to develop flexibly and efficiently;
3. PCIe interfaces offer faster transmission efficiency compared to PCI interfaces, making them more suitable for high-speed and high-precision applications;
4. The PCIe 464M board has 16 inputs and 16 outputs, eliminating the need for an adapter board and simplifying wiring;
5. Supports hybrid development using host computer + RTBasic scripting language, greatly improving the real-time execution efficiency of instructions;
6. EtherCAT synchronization cycle can be as fast as 125µs, increasing equipment productivity;
7. During the machine vision positioning and correction process, the use of rapid image capture technology reduces the machine's total contact (CT) time.
8. Twelve independent hardware position comparison outputs enable simultaneous multi-point, multi-position visual scanning, improving overall production efficiency by more than 10%.
9. Further improve accuracy; on-site measurement shows that the loading and unloading accuracy can reach ±0.02mm.
Solution Hardware Configuration
02. Ultra-high-speed PCIe EtherCAT motion control card
For high-speed, high-precision intelligent equipment, multi-axis synchronous control and high-speed, high-precision motion control are achieved in the "PC + motion control card" mode!
1. Optional 6-64 axis motion control, supporting EtherCAT bus/pulse/stepper servo drivers;
2. The maximum number of linked axes can reach 16, and the minimum control cycle is 125µs;
3. Standard configuration includes 16 inputs and 16 outputs, including 4 high-speed latch inputs, 4 high-speed PWM inputs, and 12 high-speed hardware compare outputs (PSOs).
4. Supports PWM output, 1D/2D/3D PSO hardware position comparison output, visual capture, continuous trajectory interpolation, etc.
5. Supports power-off storage and power-off interruption, with multiple encryption layers providing a more secure mechanism for the program;
6. Features one-dimensional and two-dimensional pitch compensation control, achieving higher machining accuracy;
7-8 channel single-ended pulse shafts, 4-channel single-ended encoder shafts;
8. Supports forward and inverse kinematics algorithms for 30+ robotic arm models, such as SCARA, Delta, UVW, 4-axis/5-axis RTCP...
