Self-adaptive control method for power of mining dump truck

Abstract

The invention belongs to the field of mining dump truck power control, and particularly relates to a mining dump truck power self-adaptive control method which comprises the following steps: on the basis of an optimal load rotating speed-power output curve of an engine, a driving system controller calculates the optimal load output power and the actual output power of the engine according to the running state and the working condition of a vehicle; a power sliding model is established according to working conditions of a mine car, and an optimal load rotating speed-power output curve of an engine is adjusted through an excitation controller, so that an optimal load rotating speed-power self-adaptive model of the engine with a power sliding threshold value is obtained, and self-adaptive control is performed on output power of the engine. According to the method, the actual output power of the engine can be adjusted in time under the condition that the rotating speed of the engine is not changed, so that the power requirements of the dumper under different working conditions are met, and potential safety hazards caused by engine rotating speed reduction are solved.

Description

Technical Field

[0001] The invention belongs to the field of power control of mining dump trucks, and in particular relates to a power adaptive control method for mining dump trucks. Background Art

[0002] As a key piece of engineering machinery in the mining industry, mining dump trucks primarily transport mineral resources and are crucial to open-pit mining. However, mining environments are harsh and operating conditions are complex. The dump truck's powertrain and drive system, as its core systems, directly impact the vehicle's performance.

[0003] Mining dump trucks are powered by their engines, which are directly related to their speed. Changes in speed directly impact the vehicle's power requirements. Mining operations often involve heavy-loaded uphill or downhill hauls. If the slope is too steep or the engine has undergone an overhaul, insufficient engine power can cause the engine speed to drop, making it difficult for the dump truck to climb slopes and overcome obstacles, thus impacting its performance.

[0004] Mining dump trucks often operate under heavily loaded uphill conditions, where the engine's actual output power follows the optimal load-speed-power curve. Under these conditions, if the slope is too steep or the engine has undergone an overhaul, the engine can easily drop in speed, affecting its actual output power. The engine's speed-power curve is determined by its inherent design characteristics, so external factors cannot be used to increase the engine speed, making it difficult for the truck to complete the heavily loaded uphill operation. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a power adaptive control method for a mining dump truck, which realizes adaptive control of the engine output power, avoids the engine running when the speed drops or the rated power cannot be reached after the engine overhaul, and improves the engine's performance.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A power adaptive control method for a mining dump truck is proposed. The method is based on the engine's optimal load speed-power output curve. A drive system controller calculates the engine's optimal load output power and actual output power according to the vehicle's operating status and working conditions. A power sliding model is established according to the mining truck's working conditions. The engine's optimal load speed-power output curve is adjusted by an excitation controller to obtain an optimal load speed-power adaptive model with a power sliding threshold for the engine. This is used to adaptively control the engine's output power.

[0008] Furthermore, the vehicle operating state includes vehicle speed and load; and the operating condition includes uphill operating condition and downhill operating condition.

[0009] Furthermore, the power sliding model includes a power increase threshold for an uphill operating condition and a power decrease threshold for a downhill operating condition.

[0010] Furthermore, the power increase threshold is ,

[0011] in, is the power weight of the power sliding threshold function in uphill operation, is the power up regulation function;

[0012] The lowering threshold power is ,

[0013] in, is the power weight of the power sliding threshold function in downhill conditions, is the power reduction function.

[0014] Furthermore, the excitation controller adjusts the excitation current according to the power sliding model and adjusts the optimal load speed-power output curve to slide upward or downward, thereby obtaining an optimal load speed-power adaptive model of the engine with a power sliding threshold.

[0015] Furthermore, when the actual output power of the engine is lower than the minimum required power of the mine car, the drive system controller determines it as an engine failure mode and transmits it to the vehicle controller, thereby triggering the alarm function.

[0016] The beneficial effects of the present invention are:

[0017] (1) The power adaptive control method of the present invention has strong adaptability and can solve the safety hazards caused by the speed drop problem of any type of engine.

[0018] (2) The method of the present invention can ensure that the actual output power of the engine is adjusted in time without changing the engine speed, so as to adapt to the power requirements of the dump truck under different working conditions.

[0019] (3) Even after the engine undergoes a major overhaul, the method of the present invention can still maintain the engine's output power to meet the driving function requirements of the dump truck. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the optimal load speed-power curve for the engine operation of the present invention;

[0021] Figure 2 It is the power increase threshold curve of the engine output power;

[0022] Figure 3 is the engine output power reduction threshold curve of the present invention;

[0023] Figure 4 It is the engine optimal load output power sliding model of the present invention;

[0024] Figure 5 The invention provides a power adaptive control method for a mining dump truck;

[0025] Figure 6 This is the engine output power insufficient alarm process of the present invention. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. Unless there is a conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0027] The term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Additionally, the character " / " in this document generally indicates an "or" relationship between the related objects.

[0028] The method of the present invention is further described below with reference to the accompanying drawings.

[0029] Analysis of engine optimal load speed-power change curve

[0030] like Figure 1 The figure shows the optimal load speed-power curve for the engine studied in this invention. Existing mining dump truck engines often use the optimal load speed-power curve as their loading curve, and perform power matching control with the main generator to meet the vehicle's power requirements. Therefore, based on the optimal load curve, this invention provides a power adaptive control method for dump trucks to achieve adaptive control of engine output power.

[0031] The output power of the engine under optimal load is related to its own speed and torque. The engine optimal load speed-power curve can be expressed as follows:

[0032] (1)

[0033] in, is the output power when the engine is running; is the engine's output torque; is the engine's output speed; It is the functional relationship between the output power, speed and torque under the optimal load of the engine.

[0034] When mining dump trucks are in operation, they are mostly in heavy-load uphill conditions. At this time, the actual output power of the engine will run according to the optimal load speed-power curve. If the slope is too large when heavily loaded uphill or the engine has been overhauled, the engine speed may drop, which in turn affects the actual output power of the engine. The optimal load speed-power curve of the engine is determined by the design characteristics of the engine itself. At this time, the engine speed cannot be increased by external conditions, and the mining truck is difficult to complete the heavy-load uphill condition.

[0035] exist Figure 1 The optimal load speed-power curve for the engine shown in Figure 2 shows a direct proportional relationship between engine speed and output power. As engine speed decreases, output power also decreases, leading to a decrease in the output of the main generator coaxially connected to the engine. This, in turn, reduces the power demand of the mine car's various systems, impacting its performance. If the engine's output power can be increased while maintaining constant engine speed, thereby increasing the vehicle's power consumption, the mine car's operation will be more stable and effectively avoid performance issues caused by engine speed drops.

[0036] Sliding model of engine output power under working conditions

[0037] For mining dump trucks, the traction performance when driving uphill with a heavy load and the braking performance when driving downhill with a heavy load are important indicators for testing the design performance of the dump truck. The slope angle in the mining area can better verify the driving performance of the dump truck. The inclination sensor on the mining truck can collect the slope angle of the road on which the mining truck is traveling in real time. The slope angle information collected by the inclination sensor can be divided into the following two situations.

[0038] (2)

[0039] in, It is the slope angle data collected in real time by the inclination sensor; For climbing grade; -2% can reduce the measurement error of the inclination sensor and better enhance the output power of the engine.

[0040] The present invention focuses on the slope angle, mine car speed and load, and adjusts the power threshold for the uphill and downhill working conditions of the mining dump truck. A sliding threshold function is set for the output power of the dump truck engine under different working conditions, so that the output power of the engine can be adaptively controlled to meet the power requirements under different working conditions.

[0041] Design of power sliding threshold function weights under working conditions

[0042] In order to meet the operation requirements of mine cars under different working conditions, it is necessary to change the engine output power strategy in time, calculate the minimum required power for the whole vehicle operation under different working conditions, and design a sliding threshold based on the rated operating curve of the engine. Based on this, the output power of the engine is adjusted to change the output power of the engine and ensure the stable operation of the mine car under different working conditions.

[0043] Design of power increase threshold for uphill operation

[0044] When a mining dump truck is traveling uphill with a heavy load, the engine's output power, as the vehicle's sole source of power, directly affects whether the truck can successfully complete the climb. If the slope is steep or the engine has undergone an overhaul, insufficient engine output power can cause speed drops, reducing the engine's actual output power. To ensure the truck can successfully complete the heavy-loaded uphill climb, it's necessary to increase the engine's actual output power while maintaining constant engine speed.

[0045] When the mine car is climbing, the power required by the mine car is related to the slope angle , load m and vehicle speed Then the minimum power required for the mine car to go uphill is,

[0046] (3)

[0047] in, The minimum power consumed by the uphill weak electrical system lights, alarms, etc. is the minimum power consumed by the uphill hydraulic system, The minimum power consumed by the uphill power system. It is the minimum power loss of other uphill cooling systems and between systems.

[0048] When the mine car is running, due to the influence of uncertain environmental factors and the heavy-load uphill working condition of the mine car, the actual output power of the engine is difficult to operate according to the optimal load curve of the engine, and it is difficult to meet the climbing requirements of the mine car. Therefore, in the uphill working condition, the under-output power of the engine is,

[0049] (4)

[0050] in, is the power weight of the power sliding threshold function in uphill operation; It is the actual output power of the engine when it is running under working conditions.

[0051] In order to make the mine car complete the uphill climbing condition more stably, it is necessary to increase the actual output power of the engine and set the power increase function as :

[0052]

[0053] Among them, e is a natural constant, climbing grade It can meet the design requirements of the maximum climbing grade of mining dump trucks.

[0054] In uphill conditions, the greater the actual output power of the engine, the stronger the mine car power. To increase the output power of the engine without changing the engine speed, it is necessary to change the engine speed-power curve. It is a linear function. When the sensor measurement data error is large, it is easy to cause the engine output power to be unable to meet the maximum climbing grade design requirements of the mining dump truck. In addition, the upward adjustment process is too fast, which affects the service life of the engine and is difficult to meet. In order to make the engine output power increase smoother, it is necessary to is set as a nonlinear function, and It is correlated with the slope angle, mine car speed, and mine car load. That is, the smaller the slope angle, the smaller the power sliding threshold needs to be increased for the engine's optimal load output power. As the slope angle increases, in order to complete the climbing condition, a larger power sliding threshold needs to be increased for the engine's optimal load output power.

[0055] Therefore, combining Equation (4) and the power up-regulation function The value of the power increase threshold under uphill working condition is obtained as follows:

[0056] (5)

[0057] The power increase threshold curve is as follows: Figure 2 shown.

[0058] That is, the engine output power with the power increase threshold in uphill operation is,

[0059] (6)

[0060] In formula (6), due to the setting of the power increase threshold, the optimal load output power of the engine can be increased without changing the engine speed in uphill conditions, thereby increasing the output power of the drive system and improving the transient performance of the traction motor. This makes the vehicle more flexible and the dump truck's heavy-load uphill operation smoother.

[0061] Design of power reduction threshold for downhill conditions

[0062] During heavy-load downhill driving, a dump truck's primary design performance is braking. With the slope angle designed to be negative, the engine's operation primarily maintains the vehicle's system voltage requirements to ensure stability during downhill driving and the stability of the electric brake function. A drop in engine speed poses a risk to vehicle stability. To improve engine performance and lifespan, the engine's output power can be reduced without changing the engine speed to maintain the vehicle's power supply requirements and ensure stable operation.

[0063] When the mine car is running in downhill conditions, the minimum power consumed by the mine car is related to the slope angle , load, speed Related, can be designed as,

[0064] (7)

[0065] in, The minimum power consumed by downhill weak electrical system lights, alarms, etc. is the minimum power consumed by the downhill hydraulic system, It is the minimum power consumed by the downhill strong power system. For the downhill cooling system and the minimum power loss between the systems, -25% can meet the maximum downhill slope requirements of the mine car.

[0066] In downhill conditions, if the engine operates at over-rated output power, it will damage the service life of the engine. Therefore, the over-output power of the engine is,

[0067] (8)

[0068] in, is the power weight of the power sliding threshold function in downhill conditions; It is the actual output power of the engine when it is running under working conditions.

[0069] In downhill conditions, in order to ensure the safe operation of the mine car, the output power of the mine car engine can be reduced, but the actual output power of the engine cannot be lower than the minimum power consumed by the whole vehicle in downhill conditions. Therefore, the engine output power reduction function is set to :

[0070]

[0071] Among them, e is a natural constant, climbing grade It can meet the design requirements of the maximum downhill slope of mining dump trucks.

[0072] like It is a linear function, which may cause the power to decrease too quickly, causing the engine to fail and shut down. It must be a nonlinear function, and It is related to the slope angle, minecart speed, and minecart load.

[0073] Therefore, combining Equation (8) and the power reduction function The power reduction threshold for downhill operation is obtained as follows:

[0074] (9)

[0075] The power reduction threshold curve is as follows: Figure 3 shown.

[0076] That is, the engine output power with power reduction threshold in downhill condition is,

[0077] (10)

[0078] It can be seen from formula (10) that, since lowering the threshold can reduce the output power while keeping the engine speed unchanged, the actual output power of the engine will always be greater than the minimum required power of the mine car, that is, the mine car can meet the heavy-load downhill working condition. Moreover, by reducing the output power of the engine, the working condition of the engine can be better maintained, the vehicle speed can be stabilized, the frequent switching of the accelerator and brake pedals can be avoided, and the service life of the engine can be increased.

[0079] In uphill conditions, the power increase threshold is added to the engine's optimal load output power. Similarly, in downhill conditions, the engine's optimal load output power is subtracted from the power decrease threshold, which gives equations (6) and (10). Figure 4 The engine output power sliding model is shown.

[0080] like Figure 5 As shown in the figure, based on the engine's optimal load speed-power output curve, without changing the engine speed, the drive system controller calculates the engine's optimal load output power and actual output power through the engine speed, mine car speed, mine car load, slope angle data, etc., judges the working condition of the mine car through the inclination sensor, and considers the influence of the dump truck's operating condition on the actual operating performance of the dump truck, establishes a power sliding model for power increase or decrease, and adjusts the excitation current according to the power sliding model through the excitation controller to adjust the optimal load speed-power output curve to slide upward or downward, thereby obtaining the optimal load speed-power adaptive model of the engine with a power sliding threshold to complete the adaptive control of the engine output power.

[0081] like Figure 6 As shown, the power required for the mine car to run is related to the slope angle , mine car speed It is related to the mine car load m, so the minimum required power of the mine car is the sum of the power consumed by the weak electrical system, the power consumed by the strong electrical system, the power consumed by the hydraulic system, and the power loss of other systems.

[0082] Based on the speed sensor data, the engine speed is monitored in real time, and the actual output power of the engine is determined based on the engine's optimal load speed-power adaptive model. When the actual output power of the engine is lower than the minimum required power of the mine car, the drive system controller determines it as an engine failure mode and transmits it to the vehicle controller, thereby triggering the alarm function.

[0083] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A power adaptive control method for a mining dump truck, characterized in that: Based on the engine's optimal load speed-power output curve, the drive system controller calculates the engine's optimal load output power and actual output power through the vehicle's operating status and working conditions, and establishes a power sliding model based on the mine car's working conditions. The engine's optimal load speed-power output curve is adjusted through the excitation controller to obtain the engine's optimal load speed-power adaptive model with a power sliding threshold, thereby adaptively controlling the engine's output power.

2. The power adaptive control method for a mining dump truck according to claim 1, characterized in that: The vehicle operating state includes vehicle speed and load; the operating conditions include uphill operating conditions and downhill operating conditions.

3. The power adaptive control method for a mining dump truck according to claim 1, characterized in that: The power sliding model includes a power increase threshold for an uphill operating condition and a power decrease threshold for a downhill operating condition.

4. The power adaptive control method for a mining dump truck according to claim 3, characterized in that: The power increase threshold is , in, is the power weight of the power sliding threshold function in uphill operation, is the power up regulation function; The lowering threshold power is , in, is the power weight of the power sliding threshold function in downhill conditions, is the power reduction function.

5. The power adaptive control method for a mining dump truck according to claim 1, characterized in that: The excitation controller adjusts the excitation current according to the power sliding model and adjusts the optimal load speed-power output curve to slide upward or downward, thereby obtaining an optimal load speed-power adaptive model of the engine with a power sliding threshold.

6. The power adaptive control method for a mining dump truck according to claim 1, characterized in that: When the actual output power of the engine is lower than the minimum required power of the mine car, the drive system controller determines it as an engine failure mode and transmits it to the vehicle controller, thereby triggering the alarm function.

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