A method for calculating the disassembly time of waste smart phone parts based on dynamic elements

Abstract

The application discloses a kind of based on motive force's waste and old smart phone parts disassembly time calculation method, and disassembly time calculation method is as follows: first, the disassembly process information of mainstream model smart phone is analyzed, and the basic information database of waste and old smart phone disassembly is established;Based on motive force analysis theory, determine the ten disassembly motive force of basic action, disassembly action and auxiliary disassembly action and disassembly standard time;Establish the basic action time table of waste and old smart phone parts disassembly and disassembly and auxiliary disassembly action time compensation coefficient table;Respectively construct the disassembly time calculation model of disassembly process basic action, disassembly action and auxiliary disassembly action, establish the disassembly time model of waste and old smart phone parts disassembly process, and the model is verified;Finally, the model is applied to estimate waste and old smart phone parts disassembly time.The application can optimize waste and old smart phone disassembly step, provide theoretical basis for the optimization of disassembly process, and then improve disassembly efficiency and economic benefit.

Description

Technical Field

[0001] This invention relates to the field of waste electronic product recycling and dismantling processes, specifically to a method for calculating the dismantling time of waste smartphone parts based on dynamic elements. Background Technology

[0002] Dismantling is one of the most crucial steps in the recycling of used smartphones. Currently, the high cost of dismantling used smartphones leads to low overall recycling efficiency, resulting in a less than optimistic situation. The dismantling cost and economic benefits are key factors in determining the sustainability of the dismantling process. Accurate calculation of dismantling time is essential for evaluating and optimizing the economic benefits of subsequent dismantling processes. Therefore, dismantling time is a critical parameter closely related to both dismantling costs and economic benefits.

[0003] Current research in the field of used smartphone recycling and dismantling largely focuses on optimizing dismantling sequences, equipment, and overall processes, neglecting the most fundamental element: the basic dismantling actions. In the existing used smartphone recycling and dismantling field, patent publication number CN113477679A outlines a method for generating an overall dismantling process for used smartphones, but it doesn't involve the analysis of specific dismantling actions or the calculation of dismantling time. Patent publication number CN105710115A designs a complete set of mobile phone dismantling equipment and its corresponding dismantling process, which is fundamentally different from the method for calculating the dismantling time of used smartphone parts based on dynamic elements in this patent. Currently, there are no patents related to methods for calculating the dismantling time of used smartphone parts in the field of used smartphone recycling and dismantling. Summary of the Invention

[0004] The main objective of this invention is to overcome the shortcomings and deficiencies of the prior art and propose a method for calculating the dismantling time of waste smartphone parts based on dynamic elements, providing an important foundation for the economic benefit evaluation and optimization of the dismantling process.

[0005] A method for calculating the dismantling time of discarded smartphone parts based on dynamic elements, the technical solution steps of which are as follows:

[0006] Step 1: Analyze the disassembly process information of at least 60 mainstream smartphone models on the market, conduct actual disassembly experiments on these discarded smartphones, and establish a basic information database for the disassembly of discarded smartphones.

[0007] Step 2: Based on the dynamic element analysis theory and combined with the basic information database for dismantling waste smartphones established in Step 1, the actions in the dismantling process of waste smartphone parts are divided into three categories: basic actions, dismantling actions and auxiliary dismantling actions. The three categories of actions are further subdivided into ten basic dismantling action elements, referred to as dismantling dynamic elements. The standard time for each of the ten dismantling dynamic elements is determined through dismantling experiments.

[0008] Step 3: Based on Step 1 and Step 2 above, establish a basic action schedule, a dismantling action time compensation coefficient table, and an auxiliary dismantling action time compensation coefficient table for dismantling waste smartphone parts.

[0009] Step 4: Based on Step 3, construct the dismantling time calculation models for the basic actions, dismantling actions, and auxiliary dismantling actions in the dismantling process of waste smartphone parts, and establish the dismantling time calculation model for waste smartphone parts.

[0010] Step 5: Verify the accuracy of the dismantling time calculation model for waste smartphone parts established in Step 4 through actual dismantling experiments;

[0011] Step 6: Apply the validated model for calculating the dismantling time of used smartphone parts to estimate the dismantling time of a specific model of used smartphone parts.

[0012] The basic information database for dismantling used smartphones in step 1 contains basic dismantling features that affect the calculation of dismantling time for used smartphone parts: phone model, phone size, number of parts to be dismantled, dismantling sequence of parts, part location, part size, part type, number of part constraints, type of part constraints, connection method of parts, number of parts connected, dismantling action of parts, dismantling tools, glue length, and screw length.

[0013] The ten disassembly elements in step 2 include three basic actions: moving by hand, moving with tools, and moving parts; five disassembly actions: clamping, removing screws, prying open, disassembling by hand, and lifting; and two auxiliary disassembly actions: heating and selecting / positioning. The specific definitions of the ten disassembly elements are as follows:

[0014] 1) Empty-handed Movement (EM): Definition: The process of moving from one position to another without any parts or disassembly tools in hand. The standard time is 0.4 seconds. Start point: The instant the hand begins to move. End point: The instant the hand reaches the target position. Common examples include reaching out and retracting the hand.

[0015] 2) Tool Movement: TM; Definition: The process of controlling a disassembly tool (without parts) to move from one position to another, or adjusting the angle of the disassembly tool. The standard time is 0.75s. Start point: The instant the disassembly tool is controlled and moved; End point: The instant the disassembly tool is moved to the target position. Common examples include acquiring and placing disassembly tools, pressing chuck pins, and moving disassembly tools between parts. The tool's movement speed is generally the same in all situations unless specifically indicated that slow movement is required. Tool movement time is not calculated separately during the heating process using a hot air gun.

[0016] 3) Part Movement: PM; Definition: The process of moving a part from one position to another using disassembly tools or by hand, or adjusting the angle of a part or a mobile phone. The standard time is 0.83s. Start point: The moment when the part is controlled and moved, End point: The moment when the part moves to the target position. When using disassembly tools to move parts, since the purpose is to move the part, the action at this time is recorded as part movement. Common part movement is placing the part in a designated position or adjusting the position of the part for disassembly.

[0017] 4) Clamping: denoted by C; Definition: The process of fixing or releasing a part or mobile phone using a fixing device, or the process of using a disassembly tool to clamp a part. The standard time is 1.78s. Start point: The moment when preparing to fix or release the part or mobile phone, or the moment when preparing to clamp the part; End point: The moment when fixing or releasing the part or mobile phone is completed, or the moment when the part is just clamped away from its original position; such as fixing a part or the entire mobile phone, or using tweezers to clamp a part.

[0018] 5) Screw Removal: SR; Definition: refers to the process of removing the screws that connect fasteners. The standard time is 0.79s. Start point: the instant when the action of unscrewing the screw begins; End point: the instant when the screw is completely unscrewed, that is, the instant the screw is removed from the screw hole; Small screws on old smartphones include slotted screws, Phillips screws, pentagonal screws, etc., and their length is generally in the range of 0-1cm.

[0019] 6) Pry Open: PO; Definition: refers to the process of using a disassembly tool to pry up a part at a certain angle at a certain location on the phone or to pry it off from another part. The standard time is 1.95s. Start point: the moment when the disassembly tool is placed at a certain location to pry up the part; End point: the moment when the part is pried up at a certain angle or completely pried off. Examples include using a pry bar or pry stick to pry open the back cover, or using a pry stick to pry off the BTB connector, etc.

[0020] 7) Freehand Disassembly: FD; Definition: refers to the process of directly disassembling a part by hand, causing one or all of the parts to disconnect. The standard time is 3.52 seconds. Start point: the moment when the hand is at the target part and ready to disassemble it; End point: the moment when the parts are completely disconnected. This action can be used when it is more direct and convenient to use the hand, such as disassembling a conventional snap-on back cover. Other tools can also be used to assist in disassembly before freehand disassembly.

[0021] 8) Pull up: denoted by P; Definition: The process of using a disassembly tool to pull up a part at a specific location or pulling the adhesive strip by hand to disassemble it. The standard time is 4.69 seconds. Start point: The instant when the disassembly tool or hand is in the target position and ready to pull up; End point: The instant when the part or adhesive strip ends after a forceful pull. This can also involve using a suction cup to attach to the back cover or screen and then pulling it up, or using a hand to pull up the adhesive strip.

[0022] 9) Heating: Heat, represented by H; Definition: The process of raising the temperature of a part using a heating tool to facilitate disassembly. The standard time is 19.47s. Start point: The instant the heating tool begins to heat a part; End point: The instant the heating tool stops heating a part. This action is an auxiliary disassembly action, designed to disable adhesive connections and facilitate disassembly. Efforts should be made to reduce the time of this action, such as increasing the heating temperature and ensuring uniform heating of the heating surface. Common examples of adhesively bonded electronic components include heating speakers or earpieces, back covers, screens, and heating during battery disassembly.

[0023] 10) Select Positioning (SP): Definition: To facilitate the next step of disassembly, a brief accompanying action performed in conjunction with eye movements to place disassembly tools, parts, or hands into the desired target position. The standard time is 0.4s. Start point: The instant the eyes determine the target position and the disassembly tool, part, or hand is placed in a certain position. End point: The instant the disassembly tool, part, or hand is placed in the desired target position. This action is often accompanied by eye movements for selection. This action is often accompanied by the start and end of other actions. It can be preceded by tool movement, hand movement, part movement, etc., and followed by certain disassembly actions. That is, this action can be used as an accompanying action for some basic actions and disassembly actions. Therefore, the time of this action sometimes does not need to be calculated separately.

[0024] The classification and representation of each element are shown in Table 1.

[0025] Table 1 Classification and Standard Time of Each Motion Element

[0026]

[0027] The basic action time table, disassembly action time compensation coefficient table and auxiliary disassembly action time compensation coefficient table for disassembly of used smart phone parts in the aforesaid step 3: For the basic action time, the three motion elements of empty-hand movement, tool movement and part movement each include three movement distance ranges D, i.e., 0<D≤20cm, 20<D≤40cm, 40<D≤70cm, and each movement distance range of each motion element has its corresponding movement time, wherein the time of the empty-hand movement at the distance ranges of 0<D≤20cm, 20<D≤40cm and 40<D≤70cm is 0.4s, 0.69s and 0.95s respectively; the time of the tool movement at the distance ranges of 0<D≤20cm, 20<D≤40cm and 40<D≤70cm is 0.75s, 1.37s and 1.98s respectively; the time of the part movement at the distance ranges of 0<D≤20cm, 20<D≤40cm and 40<D≤70cm is 0.83s, 1.41s and 2.01s respectively;

[0028] For the disassembly action time compensation coefficient, the compensation types of the clamping motion element include a clamping type and a fixing type, the compensation attributes of the clamping type include: snap connection only or no connection, snap connection only or adhesive connection only, adhesive connection and snap connection, and the compensation attributes of the fixing type include fixing or releasing fixing; the compensation type of the screw disassembly motion element is the screw length L, and the compensation attributes of the screw length include: 0<L≤0.3cm, 0.3<L≤0.6cm and 0.6<L≤1cm; the compensation types of the prying motion element include: snap connection, adhesive connection, and connector, the compensation attributes of the snap connection include: covered snap back cover, conventional snap back cover or screen or cover plate, and other internal parts with snap connection only, the compensation attributes of the adhesive connection include: cover plate or circuit board with adhesive connection and snap connection, back cover or screen or battery with adhesive connection, and the compensation attributes of the connector include: BTB or FPC or hasp; the compensation type of the manual disassembly motion element is the disassembly object, and the compensation attributes of the disassembly object include: parts with weak connection, conventional snap back cover, and parts with multiple or multiple-point connections; the compensation types of the pulling motion element include suction cup pulling and manual pulling, the compensation attributes of the suction cup pulling are the back cover and the screen, and the compensation attribute of the manual pulling is the easy-to-pull adhesive strip;

[0029] For the compensation coefficient of the auxiliary disassembly action time, the compensation type of the heating element is the heating object. The compensation attributes of the heating object include: batteries with 0-20cm adhesive wires, batteries with >20cm adhesive wires, screens or back covers with 0-45cm adhesive wires, screens or back covers with >45cm adhesive wires, other internal parts with 0-10cm adhesive wires, and other internal parts with >10cm adhesive wires. The compensation type of the selected positioning is the positioning type. The compensation attributes of the positioning type include normal positioning and precise positioning. Precise positioning refers to the positioning when disassembling screws and clips.

[0030] Through multiple actual disassembly experiments, the compensation coefficients corresponding to each compensation attribute were determined, as shown in Tables 2, 3, and 4.

[0031] Table 2 Basic Movement Timetable (Unit: seconds)

[0032]

[0033] Table 3. Disassembly Action Time Compensation Coefficient Table

[0034]

[0035]

[0036] Table 4. Time Compensation Coefficient for Auxiliary Disassembly Actions

[0037]

[0038] The dismantling time calculation model for the basic actions, dismantling actions, and auxiliary dismantling actions in the waste smartphone parts dismantling process in step 4, wherein the dismantling time of the basic actions is T. B The calculation model is as follows:

[0039]

[0040] Where n1 represents the number of motion elements moved by hand during disassembly, n2 represents the number of motion elements moved by tools during disassembly, n3 represents the number of motion elements moved by parts during disassembly, and T EM,i T represents the time it takes for the i-th element to move freely during the disassembly process. TM,i T represents the time it takes for the i-th tool to move during the disassembly process. PM,i T represents the time it takes for the i-th part to move during the disassembly process. EM,i T TM,i T PM,i All are determined based on the actual distance traveled, by querying the basic action schedule.

[0041] The disassembly time for the disassembly action is T. D The calculation model is as follows:

[0042]

[0043] Where n4 represents the number of clamped moving parts during disassembly, n5 represents the number of moving parts removed by screws during disassembly, n6 represents the number of moving parts pried open during disassembly, n7 represents the number of moving parts disassembled by hand during disassembly, n8 represents the number of moving parts pulled up during disassembly, and T C a represents the standard time for clamping the moving element during the disassembly process. C,i T represents the compensation coefficient for the i-th clamping element during the disassembly process. SR This indicates the standard time for screw removal during the disassembly process, a SR,i T represents the compensation coefficient for the disassembly of the i-th screw during the disassembly process. PO a represents the standard time required to pry open the moving element during the disassembly process. PO,i T represents the compensation coefficient for the i-th prying element during the disassembly process. FD a represents the standard time for manually disassembling the moving parts during the disassembly process. FD,i T represents the compensation coefficient for the i-th manually disassembled component during the disassembly process. P This indicates the standard time for lifting the dynamic element during the disassembly process, a P,i a represents the compensation coefficient for the i-th lifting element during the disassembly process. C,i a SR,i a PO,i a FD,i a P,i All are determined based on the compensation type and compensation attribute of each dynamic element;

[0044] The disassembly time for the auxiliary disassembly action is T. A The calculation model is as follows:

[0045]

[0046] Where n9 represents the number of heated components during the disassembly process, n 10 T represents the number of positioning elements selected during the disassembly process. H This indicates the standard time for heating the dynamic element during the disassembly process, a. H,i T represents the compensation coefficient for the i-th heating element during the disassembly process. SP This indicates the standard time for selecting the positioning element during the disassembly process, a SP,i a represents the compensation coefficient for the i-th selected positioning element during the disassembly process. H,i a SP,i All are determined based on the compensation type and compensation attribute of each dynamic element;

[0047] The calculation model for dismantling time of used smartphone parts is as follows:

[0048] T C =T B +T D +T A (4)

[0049] Among them, T C This refers to the disassembly time of a specific component from a discarded smartphone.

[0050] The beneficial effects of this invention are as follows:

[0051] 1) By employing the method proposed in this invention, unnecessary actions during the disassembly process can be analyzed, disassembly steps can be optimized, disassembly time can be saved, and disassembly efficiency can be improved. 2) The method proposed in this invention can provide a basis for the economic benefit assessment and optimization of the mobile phone disassembly process, improving the economic efficiency of disassembling used smartphones. Attached Figure Description

[0052] Figure 1 Method and process for calculating the dismantling time of used smartphone parts

[0053] Figure 2 Basic information database structure for dismantling discarded smartphones Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. However, it should not be construed that the scope of the invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of this invention should be included within the scope of this invention.

[0055] Example: This invention uses the motherboard cover of Xiaomi 5 and the battery disassembly of Honor 6 as examples. According to... Figure 1 The method and process for calculating the dismantling time of used smartphone parts, determining the dismantling characteristics of two phone models, and following the... Figure 2 A basic information database for the dismantling of discarded smartphones was established. The basic actions in the dismantling process of parts of two types of mobile phones were analyzed. The steps, dismantling elements and number of times the motherboard cover of the Xiaomi 5 mobile phone was dismantled are shown in Table 5.

[0056] Table 5. Disassembly steps, disassembly elements, and number of times for the Xiaomi Mi 5 mobile phone motherboard cover.

[0057]

[0058] Wherein, the length of the 9 screws on the main board cover of the Xiaomi 5 is 0.4cm, the screwdriver adopts a suspended electric screwdriver, which is placed 30cm above and in front of the mobile phone to be disassembled. The positioning during screw disassembly is precise positioning, the moving distance of the screwdriver between each screw when disassembling each screw does not exceed 20cm, after using the screwdriver, it is only necessary to send the screwdriver to a position 15cm in front of the main board cover of the mobile phone, then the screwdriver can automatically return to its position, and the removed main board cover is placed within 20cm from the mobile phone.

[0059] According to the disassembly time model established in step 4, combined with the basic action schedule, the disassembly action time compensation coefficient table, and the auxiliary disassembly action time compensation coefficient table in step 3, the disassembly time of the main board cover of the Xiaomi 5 mobile phone is calculated. According to the experimental situation described above, the empty-handed moving distance in action No. 1 is 30cm, so the action time selects the time of 0.69s under the empty-handed moving distance range of 20<D≤40cm. In action No. 2, the distance between the screwdriver and the main board cover is 30cm, so the action time selects the time of 1.37s under the tool moving distance range of 20<D≤40cm. In action No. 3 and 5, the screwdriver performs precise positioning when positioning the screw, so the compensation attribute of positioning is selected as precise positioning, with a compensation coefficient of 2. In action No. 4 and 5, the length of the disassembled screw is 0.4cm, so the compensation attribute for screw disassembly is 0.3<L≤0.6cm, with a compensation coefficient of 1.57. In action No. 5, the moving distance range of the screwdriver during screw disassembly is always kept within 20cm, so the action time for tool movement selects the time of 0.75s under the tool moving distance range of 0<D≤20cm. In action No. 6, the screwdriver is placed 15cm in front of the mobile phone main board cover, so the action time for tool movement selects the time of 0.75s under the tool moving distance range of 0<D≤20cm. In action No. 7, the distance of moving back to the cover with empty hands is 15cm, so the action time for empty-handed movement selects the time of 0.4s under the empty-handed moving distance range of 0<D≤20cm. The main board cover of the mobile phone in action No. 8 is only connected by buckles, which belongs to a weakly connected part, so the compensation attribute for manual disassembly is a weakly connected part (a part with only one type or one connection point), with a compensation coefficient of 1. In action No. 9, the main board cover is placed within 20cm, so the action time for part movement selects the time of 0.83s under the part moving distance range of 0<D≤20cm.

[0060] The calculation of the disassembly time for the main board cover of the Xiaomi 5 mobile phone is as follows:

[0061] Basic action time T B =(0.69+0.4)+(1.37+0.75+0.75*8)+0.83=10.04,

[0062] Disassembly action time TD =0 + 0.79 * 1.57 * 9 + 0 + 3.52 * 1 + 0 = 14.68

[0063] Assisted disassembly action time T A =0 + 0.4 * 2 * 9 = 7.2

[0064] Part disassembly time T C =10.04 + 14.68 + 7.2 = 31.92

[0065] Therefore, the disassembly time of the motherboard cover of the Xiaomi 5 is 31.92 seconds.

[0066] The process of disassembling the Honor 6 phone battery is summarized in Table 6, which shows the disassembly steps, disassembly elements, and number of times the Honor 6 battery is disassembled.

[0067] Table 6 shows the battery disassembly steps, disassembly components, and number of times for the Honor 6.

[0068]

[0069] The Honor 6 phone battery is glued together and connected to the motherboard via a BTB connector. The battery adhesive wire is longer than 20cm. The pry bar should be initially positioned 30cm from the phone, and the heat gun should be 60cm from the phone. After prying open the BTB connector, place the pry bar within 10cm of the phone. The heat gun should be returned to its original position. After removing the battery, place it within 20cm of the phone.

[0070] Based on the disassembly time model established in step 4, and combined with the basic action time table and disassembly time compensation coefficient table in step 3, the disassembly time of the Honor 6 mobile phone battery is calculated. According to the experimental conditions described above, in action number 1, the distance from the bare hand to the pry bar is 30cm, therefore the action time is selected as 0.69s within the range of 20 < D ≤ 40cm. In action number 2, the distance from the pry bar to the phone battery BTB is approximately 30cm, therefore the action time is selected as 1.37s within the range of 20 < D ≤ 40cm. In action number 3, the pry bar is used to pry open the BTB connector, therefore the compensation attribute for the pry is BTB, and the compensation coefficient is 1. In actions 4 and 10, the pry bar is within 10cm of the phone, therefore the action time is selected as 0.75s within the range of 0 < D ≤ 20cm. In actions 5 and 9, the distance from the pry bar to the heat gun is approximately 50cm. Therefore, the action time is selected as 0.95s for the empty-hand movement distance range of 40 < D ≤ 70cm. In action number 6, the distance the hot air gun moves above the battery is 60cm, so the action time is selected as 1.98s for the tool movement distance range of 40 < D ≤ 70cm. In action number 7, the length of the adhesive wire of the battery is >20cm, so the compensation attribute for heating is a battery with an adhesive wire of >20cm, and the compensation coefficient is 3.02. In action number 8, the distance the hot air gun moves back to its original position is 60cm, so the action time is selected as 1.98s for the tool movement distance range of 40 < D ≤ 70cm. In action number 11, the battery connected by adhesive is pried open with a pry bar, so the compensation attribute for prying open is an adhesively connected battery, and the compensation coefficient is 5.57. In action number 12, the battery is placed within 20cm of the phone, so the action time is selected as 0.83s for the part movement distance range of 0 < D ≤ 20cm.

[0071] The disassembly time for the Honor 6 phone battery is calculated as follows:

[0072] Basic motion time T B =(0.69+0.95*2)+(0.75*2+1.37+1.98*2)+0.83=10.25,

[0073] Disassembly action time T D =0+0+(1.95*1+1.95*5.57)+0+0=12.81,

[0074] Assisted disassembly action time T A =19.47*3.02+0=58.80,

[0075] Part disassembly time T C =10.25 + 12.81 + 58.80 = 81.86

[0076] Therefore, the disassembly time of the Honor 6 battery is 81.86 seconds.

[0077] To verify the accuracy of the method, a disassembly experiment was conducted. Three people with some disassembly experience were selected to disassemble old smartphones. The time taken by each person to disassemble the phone parts was recorded and compared with the calculated time to obtain the error rate between the actual disassembly time and the calculated time. The unit of disassembly time in this experiment is seconds (s). The data of the disassembly experiment are shown in Table 7.

[0078] Table 7 Part Disassembly Experimental Data

[0079]

[0080] By comparing and analyzing the time data recorded from the disassembly experiment with the time calculated using the method proposed in this invention, and finding that the total average error rate is 5.35%, this invention can accurately estimate the disassembly time of discarded smartphones, with an accuracy rate of over 94%. Therefore, it can be seen that the method for calculating the disassembly time of mobile phone parts based on dynamic elements proposed in this invention is feasible.

[0081] All technical contents not described in detail in this invention are publicly known technologies.

Claims

1. A method for calculating the dismantling time of waste smartphone parts based on dynamic elements, characterized in that... Includes the following steps: Step 1: Analyze the disassembly process information of at least 60 mainstream smartphone models on the market, and conduct actual disassembly experiments on these discarded smartphones to establish a basic information database for the disassembly of discarded smartphones. This basic information database contains the basic disassembly characteristics that affect the calculation of disassembly time for discarded smartphone parts. Step 2: Based on the motion element analysis theory and combined with the basic information database for dismantling used smartphones established in Step 1, the actions in the dismantling process of used smartphone parts are divided into three categories: basic actions, dismantling actions, and auxiliary dismantling actions. These three categories are further subdivided into ten basic dismantling action elements, referred to as dismantling motion elements. The standard time for each of the ten dismantling motion elements is determined through dismantling experiments. Auxiliary dismantling actions include heating and selection positioning (two motion elements); basic actions include hand movement, tool movement, and part movement (three motion elements); and dismantling actions include clamping, screw removal, prying, hand dismantling, and lifting (five motion elements). 1) Screw removal: refers to the process of removing the screws of the fasteners. The standard time is 0.79s. The starting point is the moment when the action of unscrewing the screw begins; the ending point is the moment when the screw is completely unscrewed and comes out of the screw hole. 2) Pry open: refers to the process of using disassembly tools to pry up a part at a certain angle at a certain location on the phone or to pry it off from another part. The standard time is 1.95s. The starting point is the moment when the disassembly tool is placed at a certain location to pry up the part, and the ending point is the moment when the part is pried up at a certain angle or completely pried off. 3) Lifting: The process of using a disassembly tool to lift a part at a certain position or pulling the easy-pull rubber strip by hand. The standard time is 4.69s. The starting point is the moment when the disassembly tool or hand is in the target position and ready to lift. The ending point is the moment when a certain position of the part or the easy-pull rubber strip ends after a forceful lifting action. 4) Heating: The process of raising the temperature of a part by using a heating tool. The standard time is 19.47s. Start point: the instant when the heating tool begins to heat a part. End point: the instant when the heating tool ends to heat a part. Step 3: Based on Step 1 and Step 2 above, establish a basic action schedule, a dismantling action time compensation coefficient table, and an auxiliary dismantling action time compensation coefficient table for dismantling waste smartphone parts. The compensation type of the screw disassembly motion element is screw length L, and the compensation attributes of the screw length include: 0<L≤0.3cm, 0.3<L≤0.6cm and 0.6<L≤1cm; the compensation types of the prying motion element include: snap connection, adhesive connection, and connector, the compensation attributes of the snap connection include: wrapped snap back cover, conventional snap back cover or screen or cover plate, and other internal parts connected only by snaps, the compensation attributes of the adhesive connection include: cover plate or circuit board connected by adhesive and snaps, back cover or screen or battery connected by adhesive, the compensation attributes of the connector include: BTB or FPC or buckle; the compensation types of the pulling motion element are suction cup pulling and manual pulling, the compensation attributes of the suction cup pulling are back cover and screen, and the compensation attribute of the manual pulling is easy-to-pull adhesive strip; the compensation type of the heating motion element is the heating object, and the compensation attributes of the heating object include: battery with 0-20cm glue line, battery with >20cm glue line, screen or back cover with 0-45cm glue line, screen or back cover with >45cm glue line, other internal parts with 0-10cm glue line, other internal parts with >10cm glue line; Step 4. Based on Step 3, establish disassembly time calculation models for the basic motions, disassembly motions and auxiliary disassembly motions in the disassembly process of used smart phone parts respectively, and establish a disassembly time calculation model for used smart phone parts; The disassembly time calculation model for used smart phone parts is as follows: （5） in, T C The disassembly time for a specific component of a discarded smartphone. T B The time required to break down the basic movements. T D The disassembly time is the time for the disassembly action, and n9 represents the number of heating elements during the disassembly process. 10 T represents the number of positioning elements selected during the disassembly process. H This indicates the standard time for heating the dynamic element during the disassembly process, a. H,i Indicates the first step in the disassembly process i The compensation coefficient for each heating element, T SP This indicates the standard time for selecting the positioning element during the disassembly process, a SP,i Indicates the first step in the disassembly process i The compensation coefficient for each selected positioning element, a H,i a SP,i All are determined based on the compensation type and compensation attribute of each dynamic element; The disassembly time for the disassembly action is T D The calculation model is as follows: (2) Where n4 represents the number of clamped moving parts during disassembly, n5 represents the number of moving parts removed by screws during disassembly, n6 represents the number of moving parts pried open during disassembly, n7 represents the number of moving parts disassembled by hand during disassembly, n8 represents the number of moving parts pulled up during disassembly, and T C a represents the standard time for clamping the moving element during the disassembly process. C,i Indicates the first step in the disassembly process i The compensation coefficient of each clamping element, T SR This indicates the standard time for screw removal during the disassembly process, a SR,i Indicates the first step in the disassembly process i The compensation coefficient for the disassembly of a screw, T PO a represents the standard time required to pry open the moving element during the disassembly process. PO,i Indicates the first step in the disassembly process i The compensation coefficient for the lever element, T FD a represents the standard time for manually disassembling the moving parts during the disassembly process. FD,i Indicates the first step in the disassembly process i The compensation coefficient for disassembling the moving parts by hand, T P This indicates the standard time for lifting the active ingredient during the disassembly process, a P,i Indicates the first step in the disassembly process i The compensation coefficient of the lifting and pulling factor, a C,i a SR,i a PO,i a FD,i a P,i All are determined based on the compensation type and compensation attribute of each dynamic element; Step 5. Verify the accuracy of the disassembly time calculation model for used smart phone parts established in Step 4 through actual disassembly experiments, and its prediction accuracy for the disassembly time of the target parts of used smart phones is not less than 94%; Step 6. Apply the verified disassembly time calculation model for used smart phone parts to estimate the disassembly time of the part disassembly process of a certain model of used smart phone.

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