A heavy mine truck whole vehicle demand torque control method

Abstract

The present application provides a kind of heavy mining truck demand torque control method, comprising the following steps: 1) determine two-dimensional query table;2) input accelerator pedal opening and power system speed;3) by linear interpolation in two-dimensional query table, obtain the demand torque of vehicle power system;It improves the safety of vehicle, on the one hand, can avoid vehicle slip, on the other hand, facilitate the control operation of driver at low vehicle speed.Especially in the reverse working condition, it is helpful for the driver to make accurate control to the vehicle running in reverse;Can improve the acceleration feeling, make the speed quickly stable under certain pedal opening, driver does not need to adjust the accelerator pedal for the expected speed, can make the driver have better driving feeling;Can be well adapted to the running scene of vehicle, when the load of vehicle changes, such as slope, rolling resistance increases, when the speed decreases, the torque will be quickly improved, still can guarantee the basic power and driving stability of vehicle.

Description

Technical Field

[0001] This invention relates to the technical field of heavy-duty mining truck vehicle control technology, specifically to a method for controlling the torque demand of a heavy-duty mining truck. Background Technology

[0002] Wheel-side drive vehicles are the main development direction for the future, and their advantages are mainly reflected in the following aspects: 1) Reducing the connection of the rear axle, making the vehicle have higher driving efficiency; 2) Lowering the drive, leaving more space for vehicle layout; 3) Wheel-side drive mode controls the wheels individually, and can automatically control the stability of the vehicle by adjusting the control of yaw moment, thus improving the driving experience.

[0003] However, mining conditions are complex. In a pure electric configuration, it is difficult for the driver to achieve good driving results by controlling the pedals in various conditions. Furthermore, the vehicle's load and empty / full status significantly affect the driver's handling experience. Especially when reversing, controlling the vehicle's movement via the pedals is extremely difficult, and improper operation can pose a significant danger.

[0004] In existing technologies, traditional control methods use a one-dimensional lookup table, where the torque output is proportional to the input accelerator pedal opening. The specific control method is as follows: Figure 1 As shown, the required torque of the vehicle at this time can be expressed as:

[0005] Tq_d = α × Tq_max(w)

[0006] Where w represents the output shaft speed (r / min), Tq_max is a function of the speed, and α represents the pedal opening (%).

[0007] The maximum output torque is divided into equal parts, and the output torque corresponds to the same proportion at different pedal openings. For example, a 40% pedal opening corresponds to 40% of the maximum output torque at the current speed.

[0008] However, as can be seen from the diagram, this control method has the following defects and problems:

[0009] 1) The same pedal opening will cause the vehicle to travel a certain distance continuously. For example, at a 40% pedal opening, the vehicle can continue to travel close to the maximum engine speed;

[0010] 2) At low speeds, the vehicle's acceleration is almost the same at the same pedal opening, which makes it difficult for the driver to maintain stable speed control.

[0011] 3) When the driver wants to maintain a stable speed, he needs to constantly adjust the pedal opening, which will affect the driving experience and fuel economy.

[0012] Especially in reversing conditions, particularly at low speeds, the driver's field of vision is limited, and it is difficult to control the torque under low-speed loads. Furthermore, the application scenarios of mining trucks are quite special, with high requirements for the reversing position during unloading and loading. Therefore, conventional torque control methods are difficult to meet the actual needs of large wheel-side vehicles in reversing situations.

[0013] Therefore, there is an urgent need to provide a method for controlling the torque demand of heavy-duty mining trucks to address the defects and shortcomings of the existing technologies. Summary of the Invention

[0014] To address the shortcomings and deficiencies in existing technologies, this invention provides a method for controlling the torque demand of heavy-duty mining trucks.

[0015] The technical solution provided by this invention is as follows:

[0016] A method for controlling the torque demand of a heavy-duty mining truck, characterized by the following steps:

[0017] 1) Determine the two-dimensional lookup table;

[0018] 2) Input the accelerator pedal opening and the engine speed;

[0019] 3) The required torque of the vehicle's powertrain is obtained by linear interpolation in a two-dimensional lookup table.

[0020] As a further preferred embodiment of the present invention, step 1) includes the following steps:

[0021] 1.1) Determine the maximum driving capability of the power system;

[0022] 1.2) Determine the maximum output torque corresponding to different pedal openings;

[0023] 1.3) Determine the vehicle speed corresponding to different pedal openings;

[0024] 1.4) Using the operating points selected under different load torques as target points, construct isopower lines corresponding to different pedal openings.

[0025] As a further preferred embodiment of the present invention, in step 1.1), the power system is selected as a dual-motor drive system.

[0026] As a further preferred embodiment of the present invention, in step 1.1), the maximum output capability of the power system's required torque is defined as:

[0027] Tq_max=Tq_TM1(w1)+Tq_TM2(w2)

[0028] in,

[0029] Tq_TM1(w1) represents the maximum output torque of the first drive motor at speed w1;

[0030] Tq_TM2(w2) represents the maximum output torque of the second drive motor at speed w2.

[0031] As a further preferred embodiment of the present invention, in step 1.2), the ratio of the pedal opening to the corresponding maximum output torque is not equal.

[0032] As a further preferred embodiment of the present invention, in step 1.2), the pedal opening ratio is lower than the ratio of its corresponding maximum output torque.

[0033] As a further preferred embodiment of the present invention, in step 1.2), the pedal opening ratios of 20%, 40%, 60%, 80%, and 100% are respectively set to the maximum output torque corresponding to the ratios of 60%, 70%, 80%, 90%, and 100%.

[0034] As a further preferred embodiment of the present invention, in step 1.3), the vehicle speed is uniformly distributed in the range of 0 to Vmax under different pedal openings.

[0035] As a further preferred embodiment of the present invention, in step 1.4), the load torque corresponding to different pedal openings does not exceed the maximum output torque corresponding to different pedal openings determined in step 1.2).

[0036] As a further preferred embodiment of the present invention, in step 1), the two-dimensional lookup table includes a resistance torque curve.

[0037] Compared with the prior art, the beneficial effects achieved by the present invention include:

[0038] 1) This invention provides a method for controlling the torque demand of a heavy-duty mining truck, which improves vehicle safety. On the one hand, it prevents the vehicle from rolling backwards, and on the other hand, it facilitates the driver's control operation at low speeds. Especially in reversing situations, it helps the driver to make precise control over the vehicle's reversing movement.

[0039] 2) This invention provides a method for controlling the torque demand of a heavy-duty mining truck, which can greatly improve the acceleration experience. Under a certain pedal opening, the engine speed will be stabilized quickly, eliminating the need for the driver to constantly adjust the accelerator pedal to achieve the desired speed, thus providing the driver with a better driving experience.

[0040] 3) This invention provides a method for controlling the torque demand of a heavy-duty mining truck, which can adapt well to the vehicle's operating scenarios. When the vehicle's load changes, such as an increase in gradient or rolling resistance, the torque will quickly increase when the speed decreases, while still ensuring the vehicle has basic power and driving stability.

[0041] 4) This invention provides a method for controlling the overall torque demand of a heavy-duty mining truck. Under the condition of the resistance torque curve, different pedal openings exhibit good acceleration at low speeds, and then gradually stabilize at the speed required by the driver. If the driver needs to accelerate, increasing the pedal opening will generate a new acceleration demand and stabilize the vehicle speed at a higher speed.

[0042] 5) This invention provides a method for controlling the torque demand of a heavy mining truck. When the scene or load changes, only a small speed fluctuation will occur at the current pedal opening. The vehicle will automatically adjust the output torque according to the speed fluctuation to reduce the large oscillation of the speed. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of a one-dimensional lookup table in the prior art.

[0044] Figure 2 The logic flowchart of the control method provided by the present invention.

[0045] Figure 3 This is a schematic diagram of the structure of the two-dimensional lookup table provided by the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0048] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0049] [First Embodiment]

[0050] like Figure 2 The diagram illustrates a method for controlling the overall torque demand of a heavy-duty mining truck according to the first embodiment of the present invention. Since the driver is most sensitive to vehicle speed during operation, a corresponding balanced vehicle speed needs to be designed for different accelerator pedal openings. This solution proposes to design the corresponding overall vehicle torque demand based on a two-dimensional lookup table using the inputs of the power system speed and accelerator pedal opening. Specifically, the method includes the following steps:

[0051] 1) Determine the two-dimensional lookup table;

[0052] 2) Input the accelerator pedal opening and the engine speed;

[0053] 3) The required torque of the vehicle's powertrain is obtained by linear interpolation in a two-dimensional lookup table.

[0054] The two-dimensional lookup table is calculated based on the driver's accelerator pedal characteristics, the powertrain's drive torque, and the vehicle's load characteristics. The table's dimensions can cover the entire powertrain's speed, accelerator pedal opening, and powertrain torque. In control, only the corresponding accelerator pedal opening and powertrain speed need to be input to obtain the required powertrain torque through linear interpolation.

[0055] The two-dimensional lookup table in this embodiment is as follows: Figure 3 As shown, the relationship between accelerator pedal opening and torque is monotonic at a given power system speed. Compared to conventional torque control methods, the two-dimensional lookup table provided in this embodiment shows that lower pedal opening corresponds to lower power, while the corresponding maximum torque is higher.

[0056] The two-dimensional lookup table in this embodiment includes a resistance torque curve, which ensures good acceleration at low speeds for different pedal openings, and then gradually stabilizes at the driver's desired speed. If the driver needs to accelerate, increasing the pedal opening will generate a new acceleration demand and stabilize the vehicle speed at a higher speed.

[0057] Meanwhile, when the scene or load changes, it will only cause a small fluctuation in speed at the current pedal opening. The vehicle will automatically adjust the output torque according to the speed fluctuation to reduce the large oscillation of speed.

[0058] The process of determining the two-dimensional lookup table in this embodiment includes the following steps:

[0059] 1.1) Determine the maximum driving capacity of the power system; since the power system in this embodiment uses a dual-motor drive system, the maximum driving capacity corresponds to 100% accelerator pedal opening. Therefore, the maximum output capacity of the required torque of its power system is defined as:

[0060] Tq_max=Tq_TM1(w1)+Tq_TM2(w2)

[0061] in,

[0062] Tq_TM1(w1) represents the maximum output torque of the first drive motor at speed w1;

[0063] Tq_TM2(w2) represents the maximum output torque of the second drive motor at speed w2;

[0064] 1.2) Determine the maximum output torque corresponding to different pedal openings; mainly considering the torque output by the power system at low vehicle speeds, and taking into account that the driver is more sensitive to torque at low speeds, in this embodiment, the ratio of pedal opening to the corresponding maximum output torque is not equal, and is specifically set to be a ratio of pedal opening percentage lower than the ratio of its corresponding maximum output torque. For example, pedal opening percentages of 20%, 40%, 60%, 80%, and 100% can be set as corresponding to maximum output torque percentages of 60%, 70%, 80%, 90%, and 100%, respectively. Those skilled in the art should know that the specific setting ratio can be set and adjusted according to the vehicle's operating requirements;

[0065] 1.3) Determine the vehicle speed corresponding to different pedal openings; In this embodiment, the vehicle speed is set to be uniformly distributed in the range of 0 to Vmax under different pedal openings to ensure that the driver can reach the desired speed under different accelerator pedal openings.

[0066] 1.4) Using the operating points selected under different load torques as target points, construct isopower lines corresponding to different pedal openings; in this step, the load torque corresponding to different pedal openings does not exceed the maximum output torque corresponding to different pedal openings determined in step 1.2).

[0067] The present invention provides a method for controlling the torque demand of a heavy-duty mining truck, which improves vehicle safety by preventing vehicle rollover on slopes and facilitating driver control at low speeds. Especially in reversing situations, it helps the driver to precisely control the vehicle's reversing motion; it also significantly improves acceleration feel, quickly stabilizing the engine speed at a certain pedal opening, eliminating the need for constant pedal adjustments to achieve the desired speed and providing a better driving experience; and it adapts well to various operating scenarios. When the vehicle load changes, such as with increased gradient or rolling resistance, the torque quickly increases even as the engine speed decreases, ensuring basic power and driving stability.

[0068] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for controlling the torque demand of a heavy-duty mining truck, characterized in that: Includes the following steps: 1) Determine the two-dimensional lookup table; 2) Input the accelerator pedal opening and engine speed; 3) The required torque of the vehicle's powertrain is obtained by linear interpolation in a two-dimensional lookup table; Step 1) includes the following steps: 1.1) Determine the maximum driving capability of the power system; 1.2) Determine the maximum output torque corresponding to different pedal openings; 1.3) Determine the vehicle speed corresponding to different pedal openings; 1.4) Using the operating points selected under different load torques as target points, construct isopower lines corresponding to different pedal openings; In step 1.2), the ratio of pedal opening to the corresponding maximum output torque is not equal; In step 1.2), the pedal opening ratio is lower than the ratio of its corresponding maximum output torque.

2. The method for controlling the torque demand of a heavy-duty mining truck according to claim 1, characterized in that: In step 1.1), the power system is a dual-motor drive system.

3. The method for controlling the torque demand of a heavy-duty mining truck according to claim 2, characterized in that: In step 1.1), the maximum output capability of the power system's required torque is defined as: Tq_max = Tq_TM1(w1) + Tq_TM2(w2) in, Tq_TM1(w1) represents the maximum output torque of the first drive motor at speed w1; Tq_TM2(w2) represents the maximum output torque of the second drive motor at speed w2.

4. The method for controlling the torque demand of a heavy-duty mining truck according to claim 1, characterized in that: In step 1.2), the pedal opening ratios of 20%, 40%, 60%, 80%, and 100% are set to the maximum output torque corresponding to the ratios of 60%, 70%, 80%, 90%, and 100%, respectively.

5. The method for controlling the torque demand of a heavy-duty mining truck according to claim 1, characterized in that: In step 1.3), the vehicle speed is uniformly distributed within the range of 0 to Vmax under different pedal openings.

6. The method for controlling the torque demand of a heavy-duty mining truck according to claim 1, characterized in that: In step 1.4), the load torque corresponding to different pedal openings does not exceed the maximum output torque corresponding to different pedal openings determined in step 1.2).

7. The method for controlling the torque demand of a heavy-duty mining truck according to claim 1, characterized in that: In step 1), the two-dimensional lookup table includes a resistance torque curve.

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