Simulation and experimental study of die-casting pickup robot

To improve the efficiency of die-casting machine pickup, the combination of SolidWorks and RobotStudio is proposed to establish a simulation workstation. In this paper, the key mechanism analysis and design of the die-casting machine pickup robot are used to determine the robot body and end-effector. SolidWorks three-dimensional software is used for die-casting pickup robot’s overall mechanical structure and workstation peripheral equipment modeling. The RobotStudio software is used for the corresponding model planning layout and Smart components to write to achieve die-casting robot workstation efficient pickup work program writing and simulation debugging. Experimental results show that the die-casting machine pickup robot completed the pickup behavior. The system has the advantages of fast response speed, high positioning accuracy, and reliable operation, effectively improving the efficiency of the production line.


Introduction
China's small and medium-sized die-casting production relies on domestic equipment, and large-scale die-casting production relies on imported equipment.Technology content is low, the degree of mechanization and automation is low, and die-casting efficiency is low.The use of a die-casting pickup workstation model can effectively solve the above problems.Therefore, the establishment of a die-casting pickup workstation model for improving the degree of automation and mechanization of die-casting plants is important significance [1][2][3][4][5] .
Taking the welding robot as the research object, in Sun et al.'s study [4] , the welding robot workstation was built by using the SolidWorks modeling function and RobotStudio simulation function.Experiments show that the simulation design of the welding workstation is helps improve labor conditions and productivity.In Li's work [7] , to ensure the stability of the automated assembly process and reduce the robot station offset, an automated assembly robot machining station tracking control method is designed.Test results show that the method can determine the best robot machining station and has good machining station optimization tracking ability and control effect.Zhang et al. [8] conducted research on multi-robot physical production line research investment, which is not easy to plan and has other issues.They proposed the combination of physical and simulation software to build a multi-robot virtual and real integration of programming methods; the results show that the multi-robot virtual and real integration of coordinated control and beat optimization method can solve the problem of existing hardware resource bottlenecks.It can further guide the design of the actual production line and the adjustment of the production plan.In Feng et al.'s work [8] , to improve the design efficiency, functional analysis, and module division of industrial robots, the appropriate product series and module types need to be chosen according to a certain way of module assembly to complete the robot design, effectively shorten the robot design cycle and design difficulty.Xie and Lv [8] carried out the experimental simulation of the robotic arm for planning welding tasks to study the motion performance of the IRB4600 robotic arm modified into a spot welding robotic arm and its working domain, which verifies the feasibility and validity of the design of robotic arm modification and motion planning.
In this paper, the end of the packaging production line die-casting pickup work is researched.SolidWorks is used to establish based on the IRB4600 robot die-casting pickup robot body, end-effector, and workstations.RobotStudio modeling and die-casting robot workstations are used for programming and simulation simulation.The laboratory die-casting robot platform is used for die-casting robot pickup experiments.The data is collected and analyzed to provide a theoretical basis for the actual die-casting workstation in the enterprise.

Key mechanism design of die-casting pickup robot
In the die-casting pickup robot hardware system, the choice of the robot body and the reasonable design of the end-effector can improve the working efficiency as well as reliability and stability.It can reduce the breakage rate in the transportation process, which is a key technical factor in logistics and transportation.

Die-casting pickup robot body selection
In this paper, the IRB4600 robot is selected, which is a 6-axis + 3 external axes to satisfy the need for flexibility, followed by a working range of up to 2.55 m, which allows access to the inside of the die-casting machine for picking parts.The characteristics of the IRB4600 robot are shown in Table 1.
Table 1.Characteristics of the IRB 4600 robot.

Specificities Clarification Short cycle
Adopting an innovative optimized design, the body is compact and lightweight, and the speed reaches the highest of its kind, ultra-fast running speed, cycle time can be shortened by 25% compared with the peer.

Large-scale
The large operating range of the IRB 4600 allows for comprehensive optimization of reach, cycle time, auxiliary equipment, and much more.

Well-protected
The Casting Expert system is IP 67 rated and includes a corrosion-resistant coating and rust-resistant mounting flanges.

Adapt according to needs
The excellent range of IRBP translators, IRBT trajectory motion systems, and motors enhance the adaptability of the IRB 4600 to the target application in every way.

End-effector design for die-casting pickup robots
An end-effector is a device specially designed for completing special operations.Nowadays, end-effectors are widely used in painting, welding, handling, measuring, cutting, and so on.The end-effector of a die-casting pickup robot is a mechanism mounted on the robot arm or mobile equipment to enable it to perform the required function.The end-effector of this project adopts the clamp type reclaimer based on the E22 CJES-7 reclaimer.The design has the following advantages: 1) simple structure, easy to install and maintain, low cost.2) high adaptability to the items: it can satisfy the gripping of our cylindrical parts, and the process of realizing it is also easier.It is a kind of mechanical material most suitable for gripping the die-castings.3) strong anti-slip: the clamping jaws of the E22 CJES-7 reclaimer have four similar rectangular jaw teeth, which are made of rubber material with certain protective clamping functions.The claw has four similar rectangular claw teeth.
The claw teeth are made of rubber material, with a certain degree of protection of the clamping function, and the clamping claw as a whole is a linkage structure through the movement of the intermediate linkage to control the clamping claw opening and closing.4) small angle to produce a large angle: based on the E22 CJES-7, reclaiming the hand of the robotic claw can be a very small angle to produce a large angle.The picking work can be accomplished with a small amount of opening.
A copycat gripper-type picker based on the E22 CJES-7 picker is shown in Figure 1.

Die-Casting pickup robot workstation construction
RobotStudio software is used to build a die-casting pickup robot workstation modeled after IZM DM180, which has the following basic components: robot body, end-effector, conveyor belt, frame holder, safety guardrail, control cabinet, etc., as shown in Figure 2.
ᬅBody (casing) ᬆShield ᬇDynamic mold ᬈDie-castings Figure 2. Die-casting machine model and components.The various work equipment of the die-casting pickup robot includes the pickup robot, the cooling table, the conveyor, the die-casting machine, the scrap box, the safety fence, and the control cabinet.About the top view of the workstation and each composition of the workstation.
The workstation covers a small area, saving space resources, and its control cabinet is located outside the workstation fence.This arrangement is designed to facilitate the staff to operate the control cabinet more conveniently, without having to enter the workstation inside, with security.
The face sensor PlaneSensor is inserted in the smart component in the RobotStudio software in the center of the robotic hand claw to detect whether it is in the position to be grasping the object block.When the face sensor PlaneSensor detects the object block, it sends out a grasping signal to the robotic hand claw.The robotic hand claw is closed to clamp the cylindrical residue of the casting, and then the object block will be removed from the static mold of the die-casting machine, completing the fetch work.

Workstation program code and debugging
The programmed points are shown in Figure 3   After the program is started, whatever state the robot is in, it will preferentially return to the Home point position.After the robot returns to the Home point, the pickup routine will be executed, and the pickup robot will move to the waiting pickup position.When the die-casting machine completes the die-casting work, and the safety gate opens, a safety gate open signal is sent, after which the pickup robot begins to enter the appropriate position between the two molds to pick up the parts.When the pickup robot is in the pickup position, the surface sensor on the end gripper will recognize whether there is an object or not; if there is an object, the robotic gripper will pick up the casting, and then the pickup robot exits the die-casting machine, along a certain path movement to the appropriate position near the quality inspection equipment.The die-casting quality inspection is completed.The workstation will issue a qualified or not signal; if the quality is qualified, the pickup robot will be placed in the die-casting cooling table; if the quality is not qualified, the pickup robot will be placed in the scrap box blocks.After the four positions of the cooling table are full, the workstation sends out a signal that the cooling table is full, and the pickup robot will clip and place the earliest die-castings placed on the cooling table to the conveyor chain.Then, the conveyor chain will transport the die-castings to the specified position, and so on.Each time the pickup robot places new die-castings in the cooling table, the earliest die-castings will be clipped and placed on the conveyor chain from the cooling table.

Analysis of experiments and studies
The end-effector used in the die-casting robot experiment platform is a gripper.There is a conveyor belt and a platform on each left and right side to simulate a die-casting conveyor belt in a real working environment.Due to the limitation of using the gripper as the end-effector, the palletization pattern of the blocks palletized on the platform is somewhat different from reality.Experiments were conducted using 40 mm x 40 mm x 20 mm cubes instead of die-castings.
The main robot positions in this experiment are pHome position, pickup position, quality inspection position, cooling table position, conveyor position, cooling table block placement position, conveyor conveying blocks, and the rotary position added due to the shape characteristics of the blocks are different from the die-casting designed in this paper.There are 6 key points in this experiment, and each point is shown in Figure 4. Since the workstation is not equipped with a conveyor module, a suitable location is used to simulate the conveyor location, and after confirming the above points, the experiment is started.After first recovering to the PHome point position, the interval position is reached.After completing the pickup, the object is moved to the quality inspection position, after which the object is placed on the cooling table.The process of placing the object on the cooling table utilizes the offs offset function to offset the cooling table position in the x and y directions.Only one point position of the cooling table position needs to be determined to complete the positional localization of the cooling of the four die-castings.After the conveyor palletizes the four blocks, the pickup robot returns to the mechanical origin, and the experiment is complete.

Conclusion
In this paper, a simulation and experimental study of a RobotStudio-based die-casting pickup robot is carried out, and the following conclusions are drawn: (1) For the key mechanism of die-casting robot design, the IRB4600 robot is selected as the die-casting robot body, and the clamp-type pickup hand is designed as the die-casting pickup robot end-effector.The experimental results show that the die-casting robot response speed is fast, and work stability is high.
(2) The 3D model is imported into RobotStudio's workstation, and the code is written and debugged using the Smart component for the IO connection, making the modeling workstation convenient and accurate.
(3) Experimental testing using the die-casting robot R&D platform is able to complete a 4x1 stacking pattern, i.e., the molds are placed as 1 layer with 4 items per layer.The equipment runs stably, verifying the feasibility of the program.
(4) The design of this die-casting workstation provides a theoretical basis and test platform for the actual die-casting workstation of the enterprise and can also plan the optimal die-casting path, reduce the cost of production line design and debugging, and provide a safe production environment for workers.Through the die-casting pickup robot workstation simulation design, it is of great significance in improving the quality and efficiency of die-casting.
.1088/1742-6596/2724/1/012008 4 below. A. Home point position B. Waiting for pickup location C. Pickup Robot Pickup Placement D. Exit die-casting machine position E. Quality testing locations F. Cooling table placement