Abstract: Based on the introduction of the system composition and control scheme of the irregular bottle packing machine, this paper proposes a solution for the conveying and sorting of irregular bottles, discusses the role of servo motor in the irregular bottle packing process and the advantages and disadvantages of different transmission schemes in the bottle grabbing and packing process, and demonstrates the role of the initial position in the control process. Keywords: Irregular bottle packing machine, servo motor 1 Introduction In the fast-moving consumer goods industry, liquid products such as wine, daily chemical products, and condiments are paying more and more attention to the personalized packaging of products. Various irregular bottles (irregular round bottles) are dazzling and enrich the market. In today's industrialized production, the packing of irregular bottles has presented a new challenge to the packaging machinery industry. Through market research, based on the standard packing machine, a packing machine adapted to irregular bottles was developed. After being put into the market, it has achieved good results and received praise from users. 2 System Composition of Irregular Bottle Packing Machine 2.1 Composition and Technical Specifications of Packing Machine (1) Composition. The irregular bottle packing machine is mainly composed of bottle conveying mechanism, box conveying mechanism, and bottle grabbing and packing mechanism, as shown in Figure 1. The bottle conveying mechanism transforms the conveying of single-row irregularly shaped bottles into multi-row bottle conveying by changing the conveying path, thus meeting the needs of bottle grabbing and boxing. The box conveying mechanism is for conveying boxes before and after bottling. The bottle grabbing and boxing mechanism packs the bottles in a regular pattern according to a certain running trajectory, and can pack one or more boxes at a time. (2) Main technical indicators. Carton size: designed and adjustable range according to user requirements; Bottle type specifications: designed and adjustable range according to user requirements; Production speed: 12 boxes/minute (adjustable); Power supply: 380V, 50HZ; Total power: 4kw; Gas consumption: 0.6m3/min, Gas pressure: 0.6Mpa. [align=center] In the figure: 1 Bottle grabbing and boxing mechanism 2 Bottle conveying mechanism 3 Box conveying mechanism Figure 1 Schematic diagram of the composition of the irregular bottle boxing machine[/align] 2.2 Control scheme of the boxing machine The control system of the irregular bottle boxing machine mainly consists of a programmable controller G1, a human-machine interface G2, servo control drivers A1 and A2, frequency converters A3 and A4, and detection/actuation elements, as shown in Figure 2. G1 and G2 constitute the core of the control system and the operation interface. All control parameters can be completed on the human-machine interface. Servo control drivers A1 and A2 drive and control servo motors M1 and M2 to complete the control of bottle rerouting and boxing processes. The PLC sends pulses to A1 and A2 through the high-speed output port, changing the pulse sending frequency and number to control the operation of the servo motors. Frequency converters A3 and A4 control motors M3 and M4 to complete the conveying of bottles and boxes. The speed and start/stop of motors M3 and M4 are controlled through the RS485 bus. [align=center]Figure 2 Schematic diagram of the control system of the irregular bottle packing machine[/align] 3 Analysis and design of the packing mechanism for bottles After product filling and labeling, bottles are conveyed to the packing equipment in single or double rows (changeable by a specific mechanism) via a conveyor chain. For round bottles, the single row can be changed to multiple rows by mutual pushing and avoiding, and the bottles form a regular arrangement in the multi-row chain. For irregular bottles, the purpose of changing from a single row to multiple rows cannot be achieved by mutual pushing and avoiding. For the packing of irregular bottles, the conveying and sorting of bottles is a key issue, and we have adopted two solutions. 3.1 One-row to multi-row conveying and sorting method The one-row to multi-row conveying and sorting method (hereinafter referred to as method 1) is shown in Figure 3. The moving device controlled by M2 sends the bottles conveyed in a single row to each of the multiple-row conveyor chain entrances in sequence, so that the conveying of one row of bottles becomes multi-row conveying. The advantage is that the conveying of bottles is almost uninterrupted. During the control of the displacement of servo motor M2, there is an initial position setting for servo motor M2. To ensure a uniform number of bottles in each lane, the number of bottles entering each lane must be counted. The number of bottles entering from the side lanes is twice that of the middle lanes to reduce the number of lane shifts. A bottle-stopping device prevents bottles from jamming during lane shifts, and the bottles move synchronously with the lane shifting mechanism. [align=center] Figure 3 Schematic diagram of bottle sorting from one column to multiple columns for irregularly shaped bottles 1. Single-column conveyor belt 2. Bottle lane-changing mechanism 3. Bottle conveying mechanism[/align] 3.2 Column-to-row step-shift conveying sorting method The column-to-row step-shift conveying sorting method (hereinafter referred to as Method 2), as shown in Figure 4, mainly consists of single and double-row conveyor chains, a single-row to double-row mechanism, and a multi-row conveyor step-shift chain. Motor M3 drives the single and double-row conveyor chains, and servo motor M2 drives the multi-row conveyor step-shift chain, moving two rows of bottles each time. The purpose of single-row to double-row is to reduce the waiting time of servo motor M2's step-shifting and increase the bottle conveying speed. This method has a simple mechanism and is relatively easy to control. 3.3 Comparison of Two Conveying and Sorting Methods Both methods share the ability to transform irregularly shaped bottles from a single-column conveyor to a multi-column conveyor, utilizing the precise operation of servo motors. Differences include: Method 1 has a more complex mechanical mechanism and control method than Method 2; Method 1 has a faster input sorting speed than Method 2; Method 1 does not change the bottle conveying direction, while Method 2 does; and Method 1 has a simpler equipment layout than Method 2. [align=center]Figure: 1 Single-column to double-column mechanism 2 Double-column bottle conveying chain 3 Multi-row bottle conveying chain Figure 4 Schematic diagram of irregularly shaped bottles being sorted from column to row[/align] 4 Design and Control of Bottle Gripping and Packing 4.1 Composition of Bottle Gripping and Packing Bottle gripping and packing mainly consists of a drive and transmission system, a bottle gripping mechanism, a box opening mechanism (for cartons), and a guiding mechanism (horizontal and vertical directions). The drive is powered by a servo motor M1, which precisely controls the operation based on the motion trajectory during the packing process. The box gripping mechanism is designed differently for different bottle and box types, allowing for the gripping of one or more boxes at a time, depending on the design. The box opening mechanism is mainly for cardboard boxes, separating the top sealing edge of the cardboard box to facilitate the loading of bottles. The function of the guiding mechanism is to guide the packing process, including both horizontal and vertical directions. The vertical guiding mechanism is installed on the horizontal guiding mechanism and can move horizontally as a whole. 4.2 Design of bottle grabbing and packing motion trajectory (1) Large sprocket transmission scheme. The transmission relationship diagram of the large sprocket transmission scheme is shown in Figure 5, which consists of driving large sprocket, conveying chain, bottle grabbing mechanism, etc. Servo motor M1 drives the large sprocket, and the small sprockets of the two passive wheels orient the transmission of the chain, improving the smoothness of transmission. The large reduction ratio reducer increases the driving torque, and the load of the bottle grabbing is concentrated on the chain. Through the guiding mechanism, under the drive of the chain, it makes two-dimensional planar motion, smoothly grabbing the bottle from the conveying chain and placing it into the empty box. [align=center] In the figure: 1 Driving large sprocket 2 Conveying chain 3 Bottle grabbing mechanism Figure 5 Schematic diagram of bottle grabbing and packing transmission relationship (1) [/align] (2) Small sprocket plus slide rail transmission scheme. Figure 6 shows the transmission relationship diagram of the small sprocket and slide rail transmission scheme. It consists of a driving small sprocket, a passive small sprocket, a transmission chain, a sliding rail, and a bottle-grabbing mechanism. The servo motor M1 drives the small sprocket, which reduces the transmission torque. The reduction ratio of the reducer is relatively reduced, which increases the torque of the driving motor. The load of the bottle grabbing is concentrated on the chain or the slide wheel. Compared with scheme 1, each has its advantages and disadvantages. Through the guide mechanism, it performs two-dimensional planar motion and smoothly picks up the bottle from the conveyor chain and puts it into the empty box. [align=center] In the figure: 1. Motion slide rail 2. Sliding connection bearing 3. Transmission chain 4. Bottle grabbing mechanism Figure 6 Schematic diagram of bottle grabbing and boxing transmission relationship (2)[/align] 4.3 The role of the initial position in the motion control process For any transmission scheme, the servo motor M1 cannot run continuously. It must run forward and reverse according to a certain running trajectory. After grabbing the bottle, it runs forward to pack the box. After putting the bottle down, it reverses and then grabs the bottle again. In order to make the servo motor M1 run in an orderly manner, the servo motor M1 must have an initial position. The initial position is generally set above the bottle grabbing position. During the packing process, if the bottles and boxes are not yet in place, the bottle-grabbing mechanism waits in the initial position. Once in place, it begins grabbing and packing. Normal shutdown stops at the initial position; in case of emergency shutdown, it stops at any position and resumes operation upon restarting. 4.4 Simple Intelligent Control Method Mechanical bottle-grabbing mechanisms may experience bottle jamming during grabbing and packing. This is detected by a photoelectric switch. For ordinary packing machines, the only solution is to stop the machine; otherwise, the bottle-grabbing head and other components will be damaged. For irregularly shaped bottle packing machines, which use servo motor control, if a bottle jams at the grabbing point, the grabbing mechanism slowly returns to the initial position and then slowly descends to the grabbing point. If a bottle jams at the packing point, the grabbing mechanism slowly reverses by the height of one bottle and then slowly descends to the packing point. During this process, the operator can promptly handle bottle jamming. If not handled promptly, and another jam is detected, the equipment automatically stops, reducing malfunctions and downtime, while protecting the bottle-grabbing mechanism from damage. 5. Conclusion The case packing machine for irregularly shaped bottles was designed with simplicity and ease of debugging in mind, effectively solving the problem of conveying and sorting irregularly shaped bottles. This case packing machine is the first to utilize the advantages of servo motors, simplifying the mechanical design. To protect the designer's technical rights, this paper discusses the methods and approaches to solving the problem; the specific implementation process and control methods are not described in detail, and we ask for the reader's understanding. By reversing the operation process and modifying the program, it can also be used as a case unloading machine.