A method for obtaining vehicle transportation routes in open-pit mines

Abstract

A method for obtaining traffic transportation routes for open-pit mines, belonging to the field of open-pit mine truck transportation, includes the steps of obtaining basic data, establishing a traffic flow planning model, and obtaining the route allocation that maximizes the total truck loading and unloading volume among the routes of all trucks dispatched during working hours for multiple transports between loading and unloading points. This method uses whether a truck is operating between loading and unloading points as a dual decision variable to ensure the maximum total truck loading and unloading volume. This overcomes the shortcomings of traditional traffic flow planning models that use transport volume or the number of truck transports between loading and unloading points as decision variables, resulting in vague planning results that cannot guide production. This method can determine the specific routes of all trucks dispatched during working hours for multiple transports between loading and unloading points, making the planning method more operational and improving the transportation efficiency of open-pit mines.

Description

Technical Field

[0001] The invention belongs to the field of open-pit mine truck transportation, and in particular relates to a method for obtaining a vehicle transportation path in an open-pit mine. Background Art

[0002] Ore and rock transportation is one of the most critical aspects of open-pit mining. Transportation costs typically account for 50% to 60% of total production costs, exceeding 60% for some deep and large open-pit mines. Truck transportation accounts for approximately 80% of the mining and stripping volume at major domestic open-pit coal mines. Truck transportation involves multiple loading and unloading points and multiple transport routes. Currently, open-pit truck transportation does not consider planning optimization. Instead, established traffic flow planning models use the transport volume or the number of truck trips between loading and unloading points as decision variables. While these methods consider certain decision factors, they still fail to address truck congestion and low transport efficiency. Consequently, their results can only be used as a reference in actual transportation processes and cannot be widely applied in engineering practice. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention aims to provide a method for obtaining a vehicle transportation path in an open-pit mine.

[0004] The technical solution adopted by the invention is: a method for obtaining the vehicle transportation path of an open-pit mine, the technical key points of which are as follows:

[0005] The steps to obtain basic data include the number of trucks, the number of loading points, the number of unloading points, the maximum number of loading and unloading times, and the average load at the loading point; the average loading and unloading time of trucks, the road distance between loading and unloading points and the average truck speed, working hours, the number of stacking equipment at the loading point, the minimum and maximum loading and unloading capacity at the loading and unloading point, the length of the truck, the stopping sight distance on the road between loading and unloading points, and the loading and unloading capacity composition of the loading and unloading points;

[0006] Based on the acquired basic data, a traffic flow planning model is established. Whether a truck is operating at a loading and unloading point is used as a decision variable. The route allocation with the maximum truck loading and unloading volume among all the trucks dispatched during working hours and multiple transports between loading and unloading points is obtained.

[0007] Trucks are transported along the route that maximizes the total amount of truck loading and unloading, as obtained by the traffic flow planning model.

[0008] In the above scheme, the objective function of the traffic flow planning model is:

[0009]

[0010] Where Q i,j is the average load of truck number i at loading point j, m 3 ;X i，j，k，lThe lth time that truck number i runs from loading point j to unloading point k, it is a decision variable with a value of 0 or 1; I is the number of trucks; J is the number of loading points; K is the number of unloading points; L represents the maximum number of loading and unloading times;

[0011] The target constraint section defines whether the truck number i runs from loading point j to unloading point k for the lth time and the truck number i runs from unloading point k to loading point j for the lth time. If it runs, the decision variable X i，j，k，l and X i,k,j,l The value is 1, otherwise it means not running, then X i,j,k,l and X i,k,j,l The value is 0;

[0012] In the above scheme, the above objective function is constrained, including:

[0013] (1) Heavy load constraint: The same truck can only carry heavy loads once from the loading point to the unloading point at most. The formula is:

[0014]

[0015] (2) No-load constraints:

[0016] (2.1) The same truck can only transport empty cargo from the unloading point to the loading point once at most. The formula is:

[0017]

[0018] Where, X i，k，j，l The truck number i runs from unloading point k to loading point j for the first time, and the value is 0 or 1;

[0019] (2.2) This constraint limits the maximum number of times a truck can transport heavy loads to the unloading point without returning to the loading point. The formula is:

[0020]

[0021] (3) Unloading point constraint: restricts the end point of heavy-load transportation and the starting point of empty transportation of the same truck to the same point; the empty-load constraint restricts the maximum number of empty-load transportation of the truck to 0, and the value range of l is L-1, which reduces the number of constraints. The formula is:

[0022]

[0023] (4) Loading point constraint: This constraint restricts the same truck’s starting point for this heavy-load transport and its ending point for the previous empty-load transport to be the same point.

[0024]

[0025] (5) Working time constraints, including:

[0026] (5.1) The number of truck loading and unloading times cannot exceed the working time. The formula is:

[0027]

[0028] Where, T i,j is the average loading time of truck number i at loading point j, including waiting time, min; S 1 j,k is the road distance from loading point j to unloading point k, km; V j,k is the average speed of trucks from loading point j to unloading point k, km / h; T x is the average truck unloading time, including waiting time, min; S 1 k,j is the road distance from unloading point k to loading point j, km; V k,j is the average speed of the truck from unloading point k to loading point j, km / h; T is the working time, h;

[0029] (5.2) The number of loading times at a loading point cannot exceed the working time. The formula is:

[0030]

[0031] Where N j is the number of stacked equipment at loading point j;

[0032] (6) Loading capacity constraint, which limits the loading capacity of the truck at the loading point. The formula is:

[0033]

[0034] Where, is the minimum loading capacity of loading point j, 10,000 m 3 ; is the maximum load capacity of loading point j, 10,000 m 3 ;

[0035] (7) Unloading capacity constraint, which limits the unloading capacity range of the truck at the unloading point. The formula is:

[0036]

[0037] Where Q k 1 is the minimum unloading amount at unloading point k, 10,000 m 3 ; is the maximum unloading capacity at unloading point k, 10,000 m 3 ;

[0038] (8) Loading and unloading frequency constraints, including:

[0039] (8.1) To limit the current truck to a heavy-load transport, it must have been dispatched for heavy-load transport last time. The formula is:

[0040]

[0041] (8.2) The truck must have been dispatched empty last time when it was dispatched empty this time. The empty-load constraint limits the maximum number of empty-load trips to 0, and the value range of l is L-1, which reduces the number of constraints. The formula is:

[0042]

[0043] (9) Traffic density constraints, including:

[0044] (9.1) The safety distance requirement for heavy-duty trucks is limited by the formula:

[0045]

[0046] Where S i is the length of the truck numbered i, m; S 2 j,k is the road stopping sight distance from loading point j to unloading point k, m;

[0047] (9.2) Limit the safety distance requirement for empty trucks. The formula is:

[0048]

[0049] Where S 2 k，j is the road stopping sight distance from unloading point k to loading point j, m;

[0050] (10) Capacity constraints, including:

[0051] (10.1) The single loading quantity of the limit loading point is:

[0052]

[0053] Where Q j is the stacking capacity of loading point j, m 3 ;

[0054] (10.2) The single unloading quantity at the unloading point is limited. The formula is:

[0055]

[0056] Where Q k is the unloading capacity of unloading point k, m 3 .

[0057] The beneficial effects of the present invention are: a method for obtaining the traffic transportation path of an open-pit mine, including the steps of obtaining basic data, establishing a traffic flow planning model to obtain the path allocation with the largest total truck loading and unloading volume in the path conditions of multiple transportations by all dispatched trucks between loading and unloading points during working hours. The method uses whether the truck is running between loading and unloading points as a dual decision variable to ensure the maximum total truck loading and unloading volume, overcoming the defects of traditional traffic flow planning models that use transportation volume as a decision variable or the number of transportations by the truck between loading and unloading points as a decision variable, and the planning results are not specific and cannot guide production. The method can determine the specific path conditions of multiple transportations by all dispatched trucks between loading and unloading points during working hours, and its planning method is more operational, thereby improving the transportation efficiency of open-pit mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0059] Figure 1 The present invention is a flowchart of a method for obtaining a vehicle transportation path in an open-pit mine according to an embodiment of the present invention. DETAILED DESCRIPTION

[0060] To make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the following Figure 1 The present invention is further described in detail with reference to the accompanying drawings and specific embodiments.

[0061] The present invention adopts a method for obtaining the vehicle transportation path of an open-pit mine, and uses this method to obtain the optimal transportation plan for an open-pit mine. The specific steps are as follows:

[0062] Step 1: Obtain basic data. The number of trucks is 20, the number of loading points is 2, and the number of unloading points is 2. The maximum number of loading and unloading times is 20. All trucks are of a uniform model. The variables related to loading and unloading points are shown in Table 1.

[0063] Table 1 Variables related to loading and unloading points

[0064]

[0065]

[0066] The average speed of trucks at loading and unloading points can be selected according to Table 2.

[0067] Table 2 Average speed of trucks

[0068]

[0069] The road parking sight distance between loading and unloading points can be selected according to Table 3.

[0070] Table 3 Driving sight distance

[0071]

[0072] Based on the data selected in Table 2-3, the relevant variables between loading and unloading points are shown in Table 4.

[0073] Table 4 Related variables between loading and unloading points

[0074]

[0075] Among the other variables, the working time is 8 hours and the truck length is 10.3 meters.

[0076] Step 2: Establish a traffic flow planning model, using whether the truck is running at the loading and unloading point as the decision variable, and obtain the path with the largest total truck loading and unloading volume among all the paths of multiple trucks transporting between loading and unloading points during working hours.

[0077] (1) The objective function is to maximize the total amount of truck loading and unloading, and the formula is:

[0078]

[0079] Where Q i,j is the average load of truck number i at loading point j, m 3 ;X i,j,k,l The truck numbered i runs from loading point j to unloading point k for the lth time. It is a decision variable with a value of 0 or 1; I is the number of trucks; J is the number of loading points; K is the number of unloading points; L represents the maximum number of loading and unloading times.

[0080] (2) Heavy load constraint: The same truck can only carry heavy loads once from the loading point to the unloading point at most. The formula is:

[0081]

[0082] (3) No-load constraints

[0083] (3.1) The same truck can only transport empty cargo from the unloading point to the loading point once at most. The formula is:

[0084]

[0085] Where, X i,k,j,l The truck numbered i runs from unloading point k to loading point j for the lth time, and the value is 0 or 1.

[0086] (3.2) The maximum number of times a truck can be loaded and transported to the unloading point without returning to the loading point is limited. The formula is:

[0087]

[0088] (4) Unloading point constraints

[0089] This constraint limits the same truck's heavy-load transport to the same destination and empty-load transport to the same point. (3) Empty-load constraint (3.2) The maximum number of empty-load transports by a truck is constrained to 0, and the value range of l is L-1, reducing the number of constraints. The formula is:

[0090]

[0091] (5) Loading point constraint: the same truck must start its current heavy-load transport at the same point as the last empty-load transport. The formula is:

[0092]

[0093] (6) Working time constraints

[0094] (6.1) The number of truck loading and unloading times cannot exceed the working time. The formula is:

[0095]

[0096] Where, T i,j is the average loading time (including waiting time) of truck number i at loading point j, min; S 1 j,k is the road distance from loading point j to unloading point k, km; V j,k is the average speed of trucks from loading point j to unloading point k, km / h; T x is the average truck unloading time (including waiting time), min; S 1 k,j is the road distance from unloading point k to loading point j, km; V k,j is the average speed of the truck from unloading point k to loading point j, km / h; T is the working time, h.

[0097] (6.2) The number of loading times at a loading point cannot exceed the working time. The formula is:

[0098]

[0099] Where N j is the number of stacked equipment at loading point j.

[0100] (7) Loading capacity constraint, which limits the loading capacity of the truck at the loading point. The formula is:

[0101]

[0102] Where, is the minimum loading capacity of loading point j, 10,000 m 3 ; is the maximum load capacity of loading point j, 10,000 m 3 .

[0103] (8) Unloading capacity constraint, which limits the unloading capacity range of the truck at the unloading point. The formula is:

[0104]

[0105] Where Q k 1 is the minimum unloading amount at unloading point k, 10,000 m 3 ;Q k 2 is the maximum unloading capacity at unloading point k, 10,000 m 3 .

[0106] (9) Loading and unloading frequency constraints

[0107] (9.1) To limit the current truck to heavy haul transport, it must have also been dispatched for heavy haul transport last time. The formula is:

[0108]

[0109] (9.2) The constraint is that the truck must have been dispatched empty last time. Similarly, the empty-load constraint (3.2) in (3) has constrained the maximum number of empty-load truck trips to 0, and the value range of l is L-1, reducing the number of constraints. The formula is:

[0110]

[0111] (10) Traffic density constraints

[0112] (10.1) The safety distance requirement for heavy-duty trucks is limited by the formula:

[0113]

[0114] Where S i is the length of the truck numbered i, m; S 2 j,k is the road stopping sight distance from loading point j to unloading point k, m.

[0115] (10.2) Limit the safety distance requirement for empty trucks. The formula is:

[0116]

[0117] Where S 2 k，j is the road stopping sight distance from unloading point k to loading point j, m.

[0118] (11) Capacity constraints

[0119] (11.1) The single loading quantity of the limit loading point is:

[0120]

[0121] Where Q j is the stacking capacity of loading point j, m 3 .

[0122] (11.2) The single unloading quantity at the unloading point is limited. The formula is:

[0123]

[0124] Where Q k is the unloading capacity of unloading point k, m 3 .

[0125] Step 3: Use the traffic flow planning model to obtain the truck transportation plan.

[0126] The traffic flow planning model in this embodiment is loaded and executed in Lingo software via multiple instructions. This embodiment uses this as an example to illustrate the solution process and is not limited to using Lingo software. This embodiment compiles four basic sets in the set segment: a truck set representing the number of trucks, with 20 elements; a loading point set representing the number of truck loading points, with 2 elements; an unloading point set representing the number of truck unloading points, with 2 elements; and a set representing the maximum number of truck loading and unloading times, with 20 elements. Derived sets are compiled to represent variables, such as the average truck load and average loading time; these are used to define variable summations and value ranges.

[0127] The data segment assigns the number of trucks to 20, the number of loading points to 2, the number of unloading points to 2, and the maximum number of loading and unloading times to 20.

[0128] The target constraint section defines whether the truck number i runs from loading point j to unloading point k for the lth time and the truck number i runs from unloading point k to loading point j for the lth time. If it runs, the decision variable X i,j,k,l and X i,k,j,l The value is 1, otherwise it means not running, then X i,j,k,l and X i,k,j,The value is 0. The average truck load is assigned values ​​of 29.6 and 27.4 for each loading point; the average loading time is assigned values ​​of 3.5 and 4.5 for each loading point; the road distance from the loading point to the unloading point is directly assigned values ​​of 3.5, 3.3, 3.2, and 3.0; the average truck speed from the loading point to the unloading point is directly assigned values ​​of 25, 25, 24, and 24; the road distance from the unloading point to the loading point is directly assigned values ​​of 3.5, 3.3, 3.2, and 3.0; and the average truck speed from the unloading point to the loading point is directly assigned values ​​of 25, 25, 24, and 24. The average unloading time of 3.5, the working time of 8, the number of stacking equipment of 2, the maximum load of 1, the minimum load of 0.5 and 0.3, the maximum unloading capacity of 1, the minimum unloading capacity of 0.5, the truck length of 10.3, the road stopping sight distance of 40, the loading capacity of 296 and 274, and the unloading capacity of 296 and 296 are directly written into the constraints; define the objective function.

[0129] Run the model, the optimal solution is 10950.6m 3 73 vehicles were transported from loading point 1 to unloading point 1, with a loading and unloading volume of 2160.8m 3 122 vehicles were transported from loading point 1 to unloading point 2, with a loading and unloading volume of 3611.2m 3 122 vehicles were transported from loading point 2 to unloading point 1, with a loading and unloading volume of 3342.8m 3 ; 67 vehicles were transported from loading point 2 to unloading point 2, with a loading and unloading volume of 1835.8m 3 .

[0130] Loading point 1 loaded 195 vehicles with a loading volume of 5772.0m 3 ; Loading point 2 loaded 189 vehicles with a loading volume of 5178.6m 3 ; Unloading point 1 unloaded 195 vehicles, with an unloading volume of 5503.6m 3 ; Unloading point 2 unloaded 189 vehicles, with an unloading volume of 5447.0m 3 ;A total of 384 vehicles were loaded and unloaded.

[0131] The loading and unloading volumes between loading and unloading points are shown in Table 5.

[0132] Table 5 Loading and unloading volume between loading and unloading points

[0133]

[0134]

[0135] The loading and unloading volumes of each numbered truck are shown in Table 6.

[0136] Table 6 Truck loading and unloading volume

[0137]

[0138] Taking the truck numbered 1 as an example, ○ is used to represent the specific path of the truck between loading and unloading points, as shown in Table 7.

[0139] Table 7 Truck route situation

[0140]

[0141]

[0142] In open-pit mines, trucks can be arranged to transport according to the above plan. The planning method can be applied in open-pit mines to guide the transportation of vehicles. The transportation plan maximizes the total loading and unloading volume and improves the transportation efficiency of open-pit mine trucks.

[0143] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for obtaining a vehicle transport path in an open-pit mine, characterized in that: The following steps are involved: The steps to obtain basic data include the number of trucks, the number of loading points, the number of unloading points, the maximum number of loading and unloading times, and the average load at the loading point; the average loading and unloading time of trucks, the road distance between loading and unloading points and the average truck speed, working hours, the number of stacking equipment at the loading point, the minimum and maximum loading and unloading capacity at the loading and unloading point, the length of the truck, the stopping sight distance on the road between loading and unloading points, and the loading and unloading capacity composition of the loading and unloading points; Based on the acquired basic data, a traffic flow planning model is established. Whether a truck is operating at a loading and unloading point is used as a decision variable. The route allocation with the maximum truck loading and unloading volume among all the trucks dispatched during working hours and multiple transports between loading and unloading points is obtained. Trucks are transported according to the route allocation obtained by the traffic flow planning model to maximize the total amount of truck loading and unloading; The objective function of the traffic flow planning model is: Where Q i,j is the average load of truck number i at loading point j, m 3 ;X i，j，k，l The decision variable is the number of trucks numbered i running from loading point j to unloading point k for the first time, which takes the value of 0 or 1; I is the number of trucks; J is the number of loading points; K is the number of unloading points; L represents the maximum number of loading and unloading times; The target constraint section defines whether the truck number i runs from loading point j to unloading point k for the lth time and the truck number i runs from unloading point k to loading point j for the lth time. If it runs, the decision variable X i，j，k，l and X i，k，j，l The value is 1, otherwise it means not running, then X i，j，k，l and X i，k，j，l The value is 0; Constraints are imposed on the objective function of the traffic flow planning model, including: (5) Working time constraints: (5.1) The number of truck loading and unloading times cannot exceed the working time. The formula is: Where, T i,j is the average loading time of truck number i at loading point j, including waiting time, min; S 1 j,k is the road distance from loading point j to unloading point k, km; V j,k is the average speed of trucks from loading point j to unloading point k, km / h; T x is the average truck unloading time, including waiting time, min; S 1 k,j is the road distance from unloading point k to loading point j, km; V k,j is the average speed of the truck from unloading point k to loading point j, km / h; T is the working time, h; (5.2) The number of loading times at a loading point cannot exceed the working time. The formula is: Where N j is the number of stacked equipment at loading point j.

2. The method for obtaining a vehicle transportation path of an open-pit mine according to claim 1, wherein: Constraining the objective function of the traffic flow planning model includes: (1) Heavy load constraint: The same truck can only carry heavy loads once from the loading point to the unloading point at most. The formula is: (2) No-load constraints: (2.1) The same truck can only transport empty cargo from the unloading point to the loading point once at most. The formula is: Where, X i，k，j，l The truck number i runs from unloading point k to loading point j for the first time, and the value is 0 or 1; (2.2) This constraint limits the maximum number of times a truck can transport heavy loads to the unloading point without returning to the loading point. The formula is:

3. The method for obtaining a vehicle transportation path of an open-pit mine according to claim 1, wherein: Constraining the objective function of the traffic flow planning model includes: (3) Unloading point constraint: restricts the end point of heavy-load transportation and the starting point of empty transportation of the same truck to the same point; the empty-load constraint restricts the maximum number of empty-load transportation of the truck to 0, and the value range of l is L-1, which reduces the number of constraints. The formula is: (4) Loading point constraint, which restricts the same truck to start the current heavy-load transport and end the previous empty-load transport at the same point; 4. The method for obtaining a vehicle transportation path of an open-pit mine according to claim 1, wherein: Constraining the objective function of the traffic flow planning model includes: (6) Loading capacity constraint, which limits the loading capacity of the truck at the loading point. The formula is: Where Q j 1 is the minimum loading capacity of loading point j, 10,000 m 3 ;Q j 2 is the maximum load capacity of loading point j, 10,000 m 3 ; (7) Unloading capacity constraint, which limits the unloading capacity range of the truck at the unloading point. The formula is: Where Q k 1 is the minimum unloading amount at unloading point k, 10,000 m 3 ;Q k 2 is the maximum unloading capacity at unloading point k, 10,000 m 3 .

5. The method for obtaining a vehicle transportation path of an open-pit mine according to claim 1, wherein: Constraining the objective function of the traffic flow planning model includes: (8) Loading and unloading frequency constraints: (8.1) To limit the current truck to a heavy-load transport, it must have been dispatched for heavy-load transport last time. The formula is: (8.2) The truck must have been dispatched empty last time when it was dispatched empty this time. The empty-load constraint limits the maximum number of empty-load trips to 0, and the value range of l is L-1, which reduces the number of constraints. The formula is:

6. The method for obtaining a vehicle transportation path in an open-pit mine according to claim 1, wherein: Constraining the objective function of the traffic flow planning model includes: (9) Traffic density constraints: (9.1) The safety distance requirement for heavy-duty trucks is limited by the formula: Where S i is the length of the truck numbered i, m; S 2 j,k is the road stopping sight distance from loading point j to unloading point k, m; (9.2) Limit the safety distance requirement for empty trucks. The formula is: Where S 2 k，j is the road stopping sight distance from unloading point k to loading point j, m.

7. The method for obtaining a vehicle transportation path of an open-pit mine according to claim 1, wherein: Constraining the objective function of the traffic flow planning model includes: (10) Capacity constraints (10.1) The single loading quantity of the limit loading point is: Where Q j is the stacking capacity of loading point j, m 3 ; (10.2) The single unloading quantity at the unloading point is limited. The formula is: Where Q k is the unloading capacity of unloading point k, m 3 .

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