Electric inertia simulation braking power test bench and electric inertia control method thereof

Abstract

The invention discloses an electric inertia simulation braking power test bench and an electric inertia control method thereof, and relates to the technical field of electric transmission simulation of flywheels, the electric inertia simulation braking power test bench comprises a motor, an incremental encoder, a main shaft, a flywheel, a force arm frame, a mechanical friction braking torque sensor, an electric transmission control system and a brake disc; an incremental encoder is installed at the rear end of the motor, the transmission end of the motor is connected with the main shaft through a coupler, the flywheel is installed on the main shaft, a brake disc is installed on the force arm frame, and meanwhile the force arm frame is connected with a mechanical friction braking torque sensor. According to the invention, the angular speed, the angular displacement and the mechanical friction braking torque are synchronously collected, and the motor torque is calculated and given, so that the test bench operates in a state of approaching an equivalent flywheel and equivalently having no system resistance; the algorithm can control the total error within a very small range; accurate matching of rotational inertia is achieved, and the control precision can meet the high-precision test requirement. And investment and operation cost are saved.

Description

Technical Field

[0001] The present invention relates to the technical field of flywheel electrical transmission simulation, in particular to an electric inertia simulation braking power test bench and an electric inertia control method thereof. Background Art

[0002] In 1:1 brake bench testing for railway rolling stock, it is necessary to measure the friction and wear performance of parking or deceleration braking under different test conditions. The requirement is to determine the kinetic energy consumed by the brake disc under various test conditions. Therefore, the brake test bench must be able to provide specific energy under different test conditions.

[0003] The load simulation of a purely mechanical simulation test bench is achieved through a flywheel. However, since the flywheel's moment of inertia is fixed or fixedly graded, it is impossible to always accurately simulate the load. This problem can be well solved through electrical inertia simulation.

[0004] During operation, mechanical friction and wind resistance in the test bench flywheel, wheel, or brake disc will generate system resistance, affecting test accuracy. Therefore, the interference of the test bench system resistance should be eliminated during the control process.

[0005] The control method of calibrating the system resistance and compensating it has the problems of large fluctuation and low precision, and cannot meet the requirements of high-precision testing. Summary of the Invention

[0006] The object of the present invention is to provide an electric inertia simulation brake power test bench and an electric inertia control method thereof, so as to solve the problems raised in the above background technology.

[0007] In a first aspect of the present invention, to achieve the above-mentioned object, the present invention provides the following technical solutions: an electric inertia simulation brake power test bench, comprising a motor, an incremental encoder, a spindle, a flywheel, a lever arm frame, a mechanical friction braking torque sensor, an electric transmission control system, and a brake disc;

[0008] An incremental encoder is installed at the rear end of the motor, the transmission end of the motor is connected to the main shaft through a coupling, the flywheel is installed on the main shaft, a brake disc is installed on the lever arm frame, and a mechanical friction braking torque sensor is connected to the lever arm frame;

[0009] The incremental encoder and mechanical friction braking torque sensor are electrically connected to the electric transmission control system respectively; the electric transmission control system drives the motor to drag the main shaft and flywheel to run to a specified speed, starting the braking process; the electric transmission control system obtains the braking torque, angular velocity, and angular displacement synchronously collected by the mechanical friction braking torque sensor and the incremental encoder, and the electric transmission control system calculates and gives the motor torque based on the mathematical model, so that the test bench operates in a state close to the equivalent flywheel and equivalent to having no system resistance.

[0010] In a specific embodiment, the motor torque T is calculated based on the mathematical model. mn The mathematical model formula is:

[0011]

[0012] t n =n·Δt n=1,2,…

[0013] t n At any moment during the braking process;

[0014] Where Δt is the control period, J is the moment of inertia of the equivalent flywheel, ω1 is the angular velocity at the start of braking, and ω n is in t n The angular velocity detected at each moment, T si is in t i (=i·Δt) The mechanical friction braking torque detected at time Δα i It is t i The angular displacement corresponding to one control cycle at time .

[0015] A second aspect of the present invention is a method for controlling electric inertia using the above-mentioned electric inertia simulation braking dynamics test bench, comprising the following steps:

[0016] Step 1: Let: control period Δt = t n -t n-1 , t n =n·Δt, n=1,2,…;

[0017] The angular velocity at the end of braking is [ω];

[0018] n=1;

[0019] Step 2: Control the motor to drag the flywheel and brake disc to a given initial braking angular velocity ω0. After the speed stabilizes, the braking process begins: timing begins at the beginning of braking, the electrical transmission control system switches to the torque control state and begins electric inertia simulation control, and the thrust loading is controlled as required. When the brake pad contacts the wheel brake disc, it is time t1. At time t1, the incremental encoder signal and the mechanical friction braking torque signal are synchronously collected; the angular velocity ω1 at time t1 is calculated based on the collected incremental encoder signal.

[0020] Step 3: Let n = n + 1

[0021] Step 4: n Synchronously collect incremental encoder signals and mechanical friction braking torque signals at all times;

[0022] Step 5: Calculate t based on the signal collected in step 4n Angular velocity ω at the moment n , angular displacement Δα n , braking torque T sn ;

[0023] Step 6: The current motor angular velocity ω obtained in step 5 n and the braking terminal speed [ω] specified in step 1, determine ω n >[ω] is true, if so, proceed with the following steps, otherwise the braking ends and the electric inertia simulation control is exited;

[0024] Step 7: Calculate t according to the mathematical model of electric inertia simulation n Motor torque T at the moment mn and given;

[0025] Step 8: Set n=n+1 and proceed to step 4.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention synchronously collects angular velocity, angular displacement, and mechanical friction braking torque, and calculates and gives the motor torque based on them, so that the test bench can operate in a state close to that of an equivalent flywheel and equivalent to having no system resistance. The algorithm can control the total error within a very small range, achieves precise matching of the moment of inertia, and the control accuracy can meet the requirements of high-precision testing, thus saving investment and operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the principle structure of the electric inertia simulation braking power test bench of the present invention.

[0029] In the figure: 1. Motor; 2. Incremental encoder; 3. Spindle; 4. Flywheel; 5. Lever frame; 6. Mechanical friction braking torque sensor; 7. Electrical transmission control system; 8. Brake disc. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] See also Figure 1 In the first aspect, the present invention provides: an electric inertia simulation braking power test bench, comprising a motor 1, an incremental encoder 2, a main shaft 3, a flywheel 4, a lever arm frame 5, a mechanical friction braking torque sensor 6, an electric transmission control system 7 and a brake disc 8.

[0032] An incremental encoder 2 is installed at the rear end of the motor 1. The transmission end of the motor 1 is connected to the main shaft 3 through a coupling. A flywheel 4 is installed on the main shaft 3. A brake disc 8 is installed on the arm frame 5. At the same time, the arm frame 5 is connected to a mechanical friction braking torque sensor 6.

[0033] The incremental encoder 2 and the mechanical friction braking torque sensor 6 are electrically connected to the electric transmission control system 7 respectively;

[0034] The electric transmission control system 7 drives the motor 1 to drag the main shaft 3 and the flywheel 4 to run to the specified speed, and the braking process begins; the electric transmission control system 7 obtains the braking torque, angular velocity, and angular displacement synchronously collected by the mechanical friction braking torque sensor 6 and the incremental encoder 2, and the electric transmission control system 7 calculates the motor torque based on the mathematical model and gives it, so that the test bench runs in a state close to the equivalent flywheel and equivalent to no system resistance.

[0035] In a specific embodiment, the motor torque T is calculated based on the mathematical model. mn The mathematical model formula is:

[0036]

[0037] t n =n·Δt n=1,2,…

[0038] t n At any moment during the braking process;

[0039] Where Δt is the control period, J is the moment of inertia of the equivalent flywheel, ω1 is the angular velocity at the start of braking, and ω n is in t n The angular velocity detected at each moment, T si is in t i (=i·Δt) The mechanical friction braking torque detected at time Δα i It is t i The angular displacement corresponding to one control cycle at time .

[0040] A second aspect of the present invention provides an electric inertia control method using the above-mentioned electric inertia simulation brake dynamics test bench, comprising the following steps:

[0041] Step 1: Let: control period Δt = t n -t n-1 , t n =n·Δt, n=1,2,…;

[0042] The angular velocity at the end of braking is [ω];

[0043] n=1;

[0044] Step 2: Control the motor 1 to drag the flywheel 4 and the brake disc 8 to a given initial braking angular velocity ω0. After the speed stabilizes, the braking process begins: timing begins at the beginning of braking, the electrical transmission control system 7 switches to the torque control state and begins electric inertia simulation control, and the thrust loading is controlled as required. When the brake pad contacts the wheel brake disc 8, it is time t1. At time t1, the incremental encoder signal and the mechanical friction braking torque signal are synchronously collected; the angular velocity ω1 at time t1 is calculated based on the collected incremental encoder signal.

[0045] Step 3: Let n = n + 1

[0046] Step 4: n Synchronously collect incremental encoder signals and mechanical friction braking torque signals at all times;

[0047] Step 5: Calculate t based on the signal collected in step 4 n Angular velocity ω at the moment n , angular displacement Δα n , braking torque T sn ;

[0048] Step 6: The current motor angular velocity ω obtained in step 5 n and the braking terminal speed [ω] specified in step 1, determine ω n >[ω] is true, if so, proceed with the following steps, otherwise the braking ends and the electric inertia simulation control is exited;

[0049] Step 7: Calculate t according to the mathematical model of electric inertia simulation n Motor torque T at the moment mn and given;

[0050] Step 8: Set n=n+1 and proceed to step 4.

[0051] Furthermore, the angular velocity, angular displacement, and mechanical friction braking torque are collected synchronously at a certain sampling point, and the motor torque is calculated and given according to the mathematical model of electric inertia simulation.

[0052] A computer control program is compiled according to the above mathematical model and its control method. The mechanical friction braking torque, angular displacement and angular velocity measured by the mechanical friction braking torque sensor and the incremental encoder are read in each control cycle, and the motor torque is calculated and given, so that the electrical transmission system controls the motor to output torque as required until the braking process is completed.

[0053] In summary, the present invention provides an effective means for precisely matching the moment of inertia in a 1:1 braking dynamic test bench for railway locomotives. By synchronously collecting angular velocity, angular displacement, and mechanical friction braking torque, the motor torque is calculated and given accordingly, allowing the test bench to operate in a state close to that of an equivalent flywheel and equivalent to no system resistance. The algorithm can control the total error within a very small range, achieve precise matching of the moment of inertia, and the control accuracy can meet the requirements of high-precision testing, thus saving investment and operating costs.

[0054] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0055] 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 within the scope of protection of the present invention.

Claims

1. An electric inertia simulation braking power test bench, characterized by: It includes a motor (1), an incremental encoder (2), a main shaft (3), a flywheel (4), a lever arm frame (5), a mechanical friction braking torque sensor (6), an electric transmission control system (7) and a brake disc (8); An incremental encoder (2) is installed at the rear end of the motor (1), a transmission end of the motor (1) is connected to a main shaft (3) via a coupling, the flywheel (4) is installed on the main shaft (3), a brake disc (8) is installed on the lever arm frame (5), and a mechanical friction braking torque sensor (6) is connected to the lever arm frame (5); The incremental encoder (2) and the mechanical friction braking torque sensor (6) are electrically connected to the electric transmission control system (7) respectively; the electric transmission control system (7) drives the motor (1) to drag the main shaft (3) and the flywheel (4) to run to a specified speed, and starts the braking process; the electric transmission control system (7) obtains the braking torque, angular velocity, and angular displacement synchronously collected by the mechanical friction braking torque sensor (6) and the incremental encoder (2), and the electric transmission control system (7) calculates the motor torque according to the mathematical model and gives it, so that the test bench runs in a state close to the equivalent flywheel and equivalent to having no system resistance.

2. The electric inertia simulation braking power test bench according to claim 1, characterized in that: Calculate the motor torque T based on the mathematical model mn The mathematical model formula is: t n At any moment during the braking process; Where Δt is the control period, J is the moment of inertia of the equivalent flywheel, ω1 is the angular velocity at the start of braking, and ω n is in t n The angular velocity detected at each moment, T si is in t i (=i·Δt) The mechanical friction braking torque detected at time Δα i It is t i The angular displacement corresponding to one control cycle at time .

3. An electric inertia control method using the electric inertia simulation braking dynamics test bench according to any one of claims 1 to 2, characterized in that: The following steps are involved: Step 1: Let: control period Δt = t n -t n-1 , t n =n·Δt, n=1,2,…; The angular velocity at the end of braking is [ω]; n＝1； Step 2, controlling the motor (1) to drag the flywheel (4) and the brake disc (8) to run to a given initial braking angular velocity ω0, and starting the braking process after the speed stabilizes: starting the timing at the same time as the braking begins, the electric transmission control system (7) switches to the torque control state to start the electric inertia simulation control, and controls the thrust loading to be executed as required, when the brake pad contacts the wheel brake disc (8), this is the time t1; synchronously collecting the incremental encoder signal and the mechanical friction braking torque signal at the time t1; and calculating the angular velocity ω1 at the time t1 based on the collected incremental encoder signal; Step 3: Let n = n + 1 Step 4: n Synchronously collect incremental encoder signals and mechanical friction braking torque signals at all times; Step 5: Calculate t based on the signal collected in step 4 n Angular velocity ω at the moment n , angular displacement Δα n , braking torque T sn ; Step 6: The current motor angular velocity ω obtained in step 5 n and the braking terminal speed [ω] specified in step 1, determine ω n >[ω] is true, if so, proceed with the following steps, otherwise the braking ends and the electric inertia simulation control is exited; Step 7: Calculate t according to the mathematical model of electric inertia simulation n Motor torque T at the moment mn and given; Step 8: Set n=n+1 and proceed to step 4.

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