Elevator drive control system and method

Abstract

The application discloses an elevator drive control method and system, which utilizes the inverse of the mathematical model of a rope, compensates the dynamic characteristics of the rope by processing the speed error of the elevator car movement as the rotor angular velocity error of the drive motor, so that the drive motor speed controller taking the drive motor as the controlled object can realize the speed control of the elevator car, wherein the rope refers to the rope between the drive sheave and the elevator car. The application converts the movement speed error of the elevator car into the rotor angular velocity error of the drive motor, compensates the dynamic characteristics of the rope, realizes the speed control of the elevator car by using the existing drive motor speed controller taking the drive motor as the controlled object, realizes the suppression of the vertical vibration of the elevator car and the improvement of the overall control performance, and the effect is particularly obvious for the elevator with large lifting height.

Description

Technical Field

[0001] This invention relates to the field of elevators, and in particular to an elevator drive control system and an elevator drive control method. Background Technology

[0002] In existing technologies, the drive control of elevator drive motors typically employs a voltage-current dual-closed-loop variable-frequency vector speed control technology to regulate the speed of the drive motor. This technology enables the drive control to achieve good performance. The design of this control system is based on a mathematical model of the drive motor, and speed feedback control utilizes the speed detection value of the drive motor. However, the control objective of the elevator drive control system is the moving speed of the elevator car. For ease of design, existing technologies rigidly connect the motor rotor and the traction sheave, making their rotational angular velocities the same. The elevator car is suspended at one end of a rope, and the counterweight is suspended at the other end. Treating the connection between the car and the rope as a rigid connection, the rotor angular velocity of the drive motor is converted to the car's angular velocity to obtain the car's converted speed, or the car's speed command is converted to the rotor angular velocity of the drive motor. Based on this, the speed detection value of the drive motor is used to achieve closed-loop speed control of the elevator drive motor, for example, by using an encoder installed on the drive motor rotor to detect the rotor angular velocity.

[0003] In reality, due to the inherent elastic damping effect of the rope, its input and output exhibit significant time delays, and the time-domain and frequency-domain characteristics of its input and output signals differ. Therefore, strictly speaking, the rope itself is also a dynamic system with its own dynamic characteristics. Existing technologies, when applying voltage-current dual-closed-loop variable-frequency vector speed control technology to regulate the speed of the drive motor, treat the connection between the car and the traction sheave as a rigid connection, neglecting the dynamic characteristics of the rope. This leads to a reduction in the final drive control performance, especially when the elevator rope has a large elastic modulus, the elevator has a large lifting height, and the car is at a low position, because the rope between the sheave and the elevator car is relatively long in these situations. This manifests as significant vertical vibration of the elevator car during movement. Therefore, to achieve better control and reduce or even eliminate vertical vibration during elevator car movement, the dynamic characteristics of the rope should not be ignored in the control system design.

[0004] In recent years, elevator car absolute position detection systems have emerged that directly detect the position of the elevator car. These systems can directly obtain the elevator car's moving speed. Obviously, by using the elevator car's speed command value and the car's moving speed detection value from the absolute position detection system, closed-loop speed control of the elevator car can be achieved. The controlled object of this speed control is the whole consisting of the elevator drive motor, ropes, and car. If only the elevator drive motor is considered and the ropes are ignored when designing the speed control, it will also lead to a reduction in its control performance. Therefore, it has the same problem as the aforementioned existing technology.

[0005] To address the vertical vibration problem during elevator car movement, Reference 1 (Japanese Patent Application Laid-Open No. 2004-123256) proposes using a notch filter to suppress elevator car vibration, but this method suffers from drawbacks such as complex parameter calculations. Reference 2 (CN201880096501.0) proposes suppressing elevator car vibration by superimposing a vibration-suppressing frequency component onto the speed command value. However, this method assumes: 1) the transmission characteristic from the drive motor to the elevator car has a second-order delay factor; 2) the attenuation coefficient of the rope is ζc = 0. These two assumptions will negatively impact the final speed control performance. Reference 3 (Vertical-vibration control of elevator using estimated car acceleration feedback compensation, IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL.47, NO.1, FEBRUARY 2000, pp.91-99) proposes using an extended full-order observer to observe the elevator car's acceleration, using a high-pass filter to filter the speed command of the drive motor to obtain the acceleration command value, and then using acceleration feedback control to suppress the vertical vibration of the elevator car. Essentially, this scheme does not analyze the causes of the elevator car's vertical vibration; it only uses simple acceleration feedback for vibration suppression. This makes its control effect heavily dependent on the accuracy of the observed car acceleration. Furthermore, since this scheme is only simple acceleration feedback, its actual control effect is very limited, leaving considerable room for improvement. References 1 to 3 all address the vertical vibration of the elevator car by reducing the vibration phenomenon, but they do not eliminate the root cause of the vibration after analyzing and identifying it. This is a simple remedial approach. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to suppress the vertical vibration of the elevator car by eliminating the root cause of the vibration after analyzing and determining the root cause of the vibration.

[0007] To address the aforementioned technical problems, this invention discloses an elevator drive control system, comprising:

[0008] The car speed command generation unit is used to generate elevator car speed command values;

[0009] The car speed detection unit is used to detect the speed at which the elevator car moves and obtain the car speed.

[0010] The first subtractor is used to calculate the difference between the elevator car speed command value and the car speed to obtain the car speed error;

[0011] A preprocessor is used to convert the car speed error into the drive motor speed error;

[0012] The drive motor speed controller takes the drive motor as the controlled object, uses the speed error of the drive motor as its input, and outputs a current command value.

[0013] The drive motor current detection unit is used to detect the current of the drive motor and obtain the motor current.

[0014] The second subtractor is used to calculate the difference between the current command value and the motor current to obtain the current error;

[0015] The drive motor current controller takes the current error as input and outputs the desired stator voltage.

[0016] Preferably, the preprocessor is configured as the inverse of a mathematical model that reflects the dynamic characteristics of the rope;

[0017] The rope refers to the rope located between the drive pulley and the elevator car;

[0018] The mathematical model is used to describe the output generated at the end of the rope connected to the elevator car after an input is applied at the end of the rope connected to the elevator drive sheave.

[0019] Preferably, the preprocessor further includes:

[0020] The modeling sub-unit is used to model the dynamic characteristics of the rope and output a mathematical model describing the dynamic characteristics of the rope.

[0021] The inverse subunit is used to perform the inverse operation on the mathematical model to obtain the inverse of the mathematical model.

[0022] Preferably, the modeling subunit uses a mechanism modeling approach to obtain the mathematical model. The model parameters in the mathematical model are functions of the rope length, the elevator car speed, the elevator car load, and the torque current and rotor angular velocity of the drive motor. The specific values ​​of the model parameters are determined by test data.

[0023] Preferably, the system further includes:

[0024] The updating unit is used to calculate the model parameters based on the input signal and response signal of the rope during elevator operation, and to update the model parameters using the calculation results;

[0025] The input signals are the elevator car load, the rope length, and the torque current and rotor angular velocity of the drive motor; the response signal is the elevator car speed.

[0026] Preferably, the system further includes:

[0027] The monitoring unit is used to monitor the difference between the response signal of the mathematical model, which takes the input signal of the rope as input, and the response signal of the rope. When the difference exceeds a threshold, the monitoring unit outputs a start command to start the update unit to perform the update function.

[0028] Preferably, the modeling subunit models the dynamics of the rope using a test data-based modeling method to obtain the mathematical model based on the test data. The modeling method includes at least one of black box system identification, neural network modeling, fuzzy model modeling, deep learning, and machine learning. The test data includes at least the input signal and response signal of the rope.

[0029] Preferably, the system further includes:

[0030] The monitoring unit monitors the difference between the response signal of the mathematical model, which takes the input signal of the rope as input, and the response signal of the rope. When the difference exceeds a threshold, the monitoring unit outputs a start command to initiate the modeling unit to remodel the mathematical model using the current new test data.

[0031] Preferably, the modeling unit models the rope using the following steps:

[0032] Step T1: Determine the factors affecting the dynamic characteristics of the rope, and the ways in which the factors affect the dynamic characteristics of the rope;

[0033] Step T2: Determine the value range of the influencing factor based on the influencing method;

[0034] Step T3: Determine the test conditions based on the influence method and the value range;

[0035] Step T4: Based on the test conditions, obtain test data for the external factors;

[0036] Step T5: Establish the mathematical model based on the test data.

[0037] This invention also discloses an elevator drive control method. By using the inverse of the mathematical model of a rope, the dynamic characteristics of the rope are compensated by processing the speed error of the elevator car movement into the rotor angular velocity error of the drive motor. This enables the drive motor speed controller, which takes the drive motor as the controlled object, to achieve speed control of the elevator car. The rope refers to the rope located between the drive sheave and the elevator car.

[0038] Preferably, the elevator drive control method includes the following steps:

[0039] Step S1: Construct a mathematical model that reflects the dynamic characteristics of the rope, and then obtain the inverse of the mathematical model;

[0040] Step S2: Design a speed control system with the drive motor as the controlled object to obtain a speed controller for the drive motor.

[0041] Step S3: Use the inverse of the mathematical model to convert the car speed error into the drive motor speed error;

[0042] Step S4: Use the speed error of the drive motor as the input of the speed controller to control the speed of the drive motor, thereby achieving speed control facing the elevator car.

[0043] Preferably, step S1 uses a mechanism modeling approach to obtain the mathematical model. The model parameters in the mathematical model are functions of the rope length, the elevator car speed, the elevator car load, and the torque current and rotor angular velocity of the drive motor. The specific values ​​of the model parameters are determined by test data.

[0044] Preferably, the elevator drive control method further includes step S5, which monitors the difference between the response signal of the mathematical model with the input data of the rope as input and the rope response signal. When the difference exceeds a threshold, the model parameters are calculated based on the input signal of the rope and the response signal of the rope during elevator operation, and the model parameters are updated using the calculation results.

[0045] Preferably, in step S1, the dynamics of the rope are modeled by a modeling method based on test data to obtain the mathematical model based on the test data. The modeling method includes at least one of black box system identification, neural network modeling, fuzzy model modeling, deep learning, and machine learning. The test data includes at least the input signal and response signal of the rope.

[0046] Preferably, the elevator drive control method further includes step S5, monitoring the difference between the response signal of the mathematical model with the input data of the rope as input and the actual output of the rope. When the difference exceeds a threshold, the monitoring unit outputs a start command to start the modeling unit to remodel the mathematical model using the current new test data.

[0047] This invention compensates for the dynamic characteristics of the rope by converting the actual moving speed error of the elevator car into the angular velocity error of the drive motor rotor. It utilizes an existing drive motor speed controller with the drive motor as the controlled object to achieve speed control of the elevator car and suppress vertical vibration of the elevator car, which is particularly effective for elevators with large lifting heights. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of an existing elevator drive system;

[0049] Figure 2 These are schematic diagrams of the elevator drive control systems in Examples 1 and 2;

[0050] Figure 3 This is a schematic diagram of the rope modeling steps in Example 2;

[0051] Figure 4 These are schematic diagrams of the elevator drive control methods in Examples 3 and 4;

[0052] Figure 5 This is a schematic diagram of the rope modeling steps in Example 4. Detailed Implementation

[0053] To better understand the present invention, before describing the embodiments of the present invention in detail, a specific implementation of a conventional elevator drive system will be described by way of example.

[0054] like Figure 1 As shown, an elevator drive system typically includes a three-phase power supply, an elevator control cabinet, a traction machine containing a drive motor and drive sheaves, and a detection unit required for detecting drive control. Figure 1The diagram shows a common drive system employing dual closed-loop voltage and current control and AC variable frequency speed regulation technology. Three-phase power supply provides electrical energy to the elevator system; the elevator control cabinet receives operation information from passengers and detection information from the elevator detection unit to control the elevator, thus providing transportation services to passengers. For the drive, the elevator control cabinet primarily receives electrical energy from the three-phase power supply and, under the control of the drive motor controller, converts the electrical energy from the power supply using the switching of the power module, then transmits the converted electrical energy to the drive motor; the drive motor, under the action of the converted electrical energy from the control cabinet, rotates in the desired manner (mainly referring to speed), driving the drive sheave to rotate; a drive rope with a fixed section for the elevator car and a counterweight fixed to the other end is suspended on the drive sheave. When the drive sheave... During rotation, the elevator car moves up and down in the shaft. Current detection and speed detection are mainly used to detect the actual current and speed of the drive motor required for the dual closed-loop control of voltage and current of the drive motor. Speed ​​detection is usually based on an encoder installed on the drive elevator rotor. The drive motor controller and pulse width modulation unit are located in the elevator control cabinet, usually in the microprocessor and printed circuit board inside the control cabinet. It mainly outputs appropriate PWM signals after processing the obtained passenger operation information and detection information, or other relevant elevator information in the controller. These PWM signals are used to control the power modules in the control cabinet to turn on and off.

[0055] Depend on Figure 1 It can be seen that a conventional drive motor controller mainly consists of a drive motor speed controller, a drive motor current controller, and two subtractors. Its working principle and process are as follows: the first subtractor receives the given motor speed command value v. motor_ref and the drive motor speed v detected by the drive motor speed detection unit motor The speed error e of the drive motor is obtained after performing subtraction calculation. v The drive motor speed controller will control the speed error e. v As input, the current command value i for driving the motor is obtained after processing. motor_ref The second subtractor uses the current command value i of the drive motor. motor_ref The actual current value and rotational speed i of the drive motor detected by the drive motor current detection unit. motor The input is used as the input, and the speed error e is obtained after performing a subtraction calculation. i The drive motor current controller will control the current error e. iAs input, the desired stator voltage u of the drive motor is obtained after processing; the pulse width modulation unit uses the desired stator voltage u as a modulation wave to generate and output switching signals for turning the power module on and off; the power module turns on and off under the control of the switching signals, thereby processing and converting the electrical energy from the grid, so that the converted electrical energy is sent to the drive motor; after receiving the converted electrical energy, the actual rotational speed of the drive motor rotor can track the motor speed command value v. motor_ref .

[0056] As explained above, although the purpose of elevator drive control is to control the speed of the elevator car in the shaft, it actually ignores the dynamic characteristics of the drive rope between the drive sheave and the elevator car. The drive sheave and the elevator car are considered to be rigidly connected. Thus, the speed of the elevator car in the shaft can be converted into the rotor angular velocity of the drive motor after a certain coefficient conversion. Using this, the speed command of the elevator car can be converted into the speed command value of the drive motor. In this way, the controller can be designed entirely for the drive motor, such as the voltage and current dual closed-loop variable frequency speed control mentioned above. However, in reality, the drive rope located between the drive sheave and the elevator car possesses specific dynamic characteristics. When the elevator's lifting height and speed are not particularly high, these dynamic characteristics are not very pronounced. Under the control of a controller designed solely for the drive motor while ignoring the dynamic characteristics of the drive rope, the controller's inherent robustness (primarily through negative feedback) can effectively compensate for the negative impact caused by model deviations between the mathematical model of the controlled object (which should ideally be a combination of drive motor and drive rope, but is reduced to just the drive motor) and the actual model of the controlled object (the combination of drive motor and drive rope). However, in specific scenarios such as when the elevator lifting height is very high, the dynamic characteristics of the drive rope between the drive sheave and the elevator car become so significant that they cannot be ignored (i.e., the controller's robustness is insufficient to adequately compensate for the negative impact of model deviations between the mathematical model of the controlled object and the actual model of the controlled object). In such cases, it is necessary to analyze how the dynamic characteristics of the drive rope affect the elevator drive control performance and implement targeted special treatment.

[0057] In other words, the reason why conventional elevator drive control systems deteriorate in applications involving large lifting heights is that:

[0058] 1) Its speed controller is designed with the drive motor as the controlled object, but the actual controlled object should be the combination of the drive motor and the drive rope located between the drive sheave and the elevator car.

[0059] 2) Simply converting the elevator car speed command into the drive motor rotor angular velocity command by multiplying by a conversion factor introduces a large conversion error, including both phase and amplitude errors.

[0060] Example 1

[0061] like Figure 2 As shown, the elevator drive control system of this embodiment includes: a car speed command generation unit 1, a car speed detection unit 8, a first subtractor 2, a preprocessor 3, a drive motor speed controller 4, a second subtractor 5, a drive motor current controller 6, and a drive motor current detection unit 7.

[0062] Car speed command generation unit 1 is used to generate elevator car speed command value v car_ref The car speed detection unit 8 is used to detect the speed of the elevator car and obtain the car speed v. car The car speed detection unit 8 can, exemplarily, employ an elevator car absolute position detection system, or exemplarily employ a speed sensor or acceleration sensor fixed to the car; the first subtractor 2 is used to calculate the elevator car speed command value v. car_ref With the car speed v car The difference between the values ​​yields the car speed error e. car_v Preprocessor 3 checks the car speed error e car_v Speed ​​error e converted to drive motor v The controlled object of the speed controller is changed from the combination of the drive motor and the rope located between the drive sheave and the elevator car to the drive motor; the drive motor speed controller 4 takes the drive motor as the controlled object and controls the speed error e of the drive motor. v As its input, the output current command value i motor_ref The drive motor current detection unit 7 is used to detect the current of the drive motor and obtain the motor current i. motor The second subtractor 5 is used to calculate the current command value i. motor_ref With the motor current i motor The difference between them yields the current error e. i The drive motor current controller 6 uses the current error e i The input is the desired stator voltage u.

[0063] The pulse width modulation unit generates and outputs a switching signal for turning the power module on and off by using the desired stator voltage u as the modulation wave. The power module turns on and off under the control of the switching signal, thereby processing and converting the electrical energy from the power grid. After the converted electrical energy is sent to the drive motor, the rotor of the drive motor rotates, driving the elevator car to move up and down in the hoistway.

[0064] Preprocessor 3 is configured as the inverse of a mathematical model reflecting the dynamic characteristics of the rope; the rope refers to the rope located between the drive sheave and the elevator car; the mathematical model describes the output generated at the end of the rope connected to the elevator car after an input is applied to the end where the rope connects to the elevator drive sheave. From the position of the rope in the elevator drive system and its interaction with other components, it is known that the end of the rope connected to the drive sheave is subjected to rotational action from the drive sheave, including the torque and angular velocity transmitted from the drive sheave to the connected end of the rope. In practice, considering that the parameters of the rope in transmitting force and velocity change with the movement of the elevator car, in addition to using the torque and angular velocity from the drive sheave as inputs to the rope, variables affecting the rope output, such as rope length and load within the car, should also be used as inputs. These input signals, after being transmitted through the dynamic characteristics of the rope, are manifested at the end where the rope connects to the elevator car, including velocity and force. Therefore, the output response signal is the velocity at the end where the rope connects to the elevator car and the force exerted by the rope on the elevator car. The input signals are the elevator car load, the rope length, the torque current of the drive motor, and the rotor angular velocity, while the response signal is the elevator car speed.

[0065] The preprocessor 3 includes a modeling subunit and an inverse subunit. The modeling subunit is used to model the rope and output a mathematical model of the rope's dynamic characteristics. The inverse subunit is used to perform an inverse operation on the mathematical model to obtain its inverse. There are various mathematical models describing the dynamic characteristics of dynamic systems, such as transfer functions, differential (state) equations, step input / output, pulse input / output, etc. The types and characteristics of mathematical models for dynamic systems are not the focus of this application and will not be discussed in detail here. For specific information, please refer to relevant automatic control books, such as Norman S. Nise, *Control Systems Engineering*, 8th Edition, Wiley, 2019.

[0066] When describing the dynamic characteristics of the drive rope located between the drive sheave and the elevator car using a state equation, the state equation can be expressed as equation (1):

[0067]

[0068] In the formula, the state variable X = [T, ω] T T is the output torque of the drive motor, ω is the rotor angular velocity of the drive motor, d is the length of the drive rope located between the drive sheave and the elevator car, and G(·) and H(·) are appropriate functions.

[0069] When described using a transfer function, its transfer function G 2m (S) is expressed as equation (2):

[0070]

[0071] In the formula,

[0072] Considering that the input-output characteristics described by the mathematical model are exactly the opposite of those required in preprocessor 3, preprocessor 3 needs to be set as the inverse model of the rope's mathematical model, i.e., the transfer function G. 2m The inverse of (S) is necessary to reduce the speed error e of the elevator car. car_v Speed ​​error e converted to drive motor v This allows for the efficient use of existing speed and current controllers to effectively control the speed of the elevator drive system. Furthermore, even if there is a certain deviation in the inverse of the mathematical model set in the preprocessor 3, the robust performance formed by the speed feedback in the control system can compensate for this deviation well, thereby ensuring the final control performance and reducing the impact of the dynamic characteristics of the rope on the vertical vibration of the car.

[0073] The mathematical model G is obtained by using a mechanistic modeling approach for the modeling subunit. 2m (S), mathematical model G 2m The model parameters in (S) are functions of the rope length, elevator car speed, elevator car load, and the torque current and rotor angular velocity of the drive motor, and the specific values ​​of the model parameters are determined by test data. For example, the model parameters m, n, and a in equation (2) are... i (i = 1, ..., p) and b j (j = 1, ..., r). Of course, after obtaining the inverse of the model, the parameters in the inverse of the model can also be determined from the test data.

[0074] It should be noted that, under certain special circumstances, the mathematical model of the rope may be a non-minimum phase system. In such cases, special processing is required to perform the inversion operation. For details, please refer to relevant materials.

[0075] Preferably, this embodiment may further include an update unit, which is used to calculate model parameters based on the input signal and response signal of the rope during elevator operation, and update the model parameters using the calculation results.

[0076] The update unit can compensate for the changes in the dynamic characteristics of the rope after a certain period of use by updating the model parameters.

[0077] Preferably, the elevator drive control system of this embodiment may further include a monitoring unit. The monitoring unit monitors the difference between the response signal of the mathematical model with the input signal of the rope as input and the response signal of the rope. When the difference exceeds a threshold, the monitoring unit determines that an update is required, and therefore outputs a start command to start the update unit to perform the update function.

[0078] The monitoring unit can track whether the mathematical model has sufficient accuracy, and execute the update function when the accuracy is lower than a preset threshold.

[0079] Example 2

[0080] The difference between this embodiment and Embodiment 1 is that the modeling subunit uses a modeling method based on test data to model the dynamic characteristics of the rope. The other features are basically the same as those in the embodiment. The differences are further explained below.

[0081] The modeling subunit of this embodiment uses a modeling method based on test data to model the dynamics of the rope, thereby obtaining the mathematical model based on the test data. The modeling method includes at least one of black box system identification, neural network modeling, fuzzy model modeling, deep learning, and machine learning. The test data includes at least the input signal and response signal of the rope.

[0082] like Figure 3 As shown, the modeling subunit models the rope using the following steps:

[0083] Step T1: Determine the factors affecting the dynamic characteristics of the rope, and the ways in which these factors affect the dynamic characteristics of the rope.

[0084] Step T2: Determine the range of values ​​for the influencing factors based on the mode of influence;

[0085] Step T3: Determine the test conditions based on the influence method and value range;

[0086] Step T4: Based on the test conditions, obtain test data on external factors;

[0087] Step T5: Establish a mathematical model based on the test data.

[0088] Preferably, the elevator drive control system further includes a monitoring unit that monitors the difference between the response signal of the mathematical model, which takes the input signal of the rope as input, and the response signal of the rope. When the difference exceeds a threshold, the monitoring unit outputs a start command to activate the modeling subunit to remodel the mathematical model using the new test data.

[0089] Another implementation method is that preprocessor 3 does not need to establish modeling sub-units and inverse sub-units. Instead, preprocessor 3 directly establishes the inverse model of the rope dynamics using a modeling method based on test data. The modeling method is the same as the modeling method described above in this embodiment.

[0090] Example 3

[0091] like Figure 4 As shown, this embodiment is an elevator drive control method. It utilizes the inverse of the mathematical model of a rope to compensate for the dynamic characteristics of the rope by processing the speed error of the elevator car's movement into the rotor angular velocity error of the drive motor. Furthermore, it transforms the controlled object facing the speed loop from a combination of the drive motor and the rope into the drive motor itself, thereby enabling the speed control of the drive motor facing the drive motor to achieve speed regulation control of the elevator car. Here, the rope refers to the rope located between the drive sheave and the elevator car.

[0092] The elevator drive control method includes the following steps:

[0093] Step S1: Construct a mathematical model that reflects the dynamic characteristics of the rope, and then obtain the inverse of the mathematical model. The rope refers to the rope located between the drive sheave and the elevator car.

[0094] Step S2: Design a speed control system with the drive motor as the controlled object to obtain a speed controller for the drive motor.

[0095] Step S3: Use the inverse of the mathematical model to convert the car speed error into the drive motor speed error;

[0096] The speed error of the drive motor is used as the input of the speed controller to adjust the speed of the drive motor, thereby achieving speed control facing the elevator car.

[0097] Step S4: Use the speed error of the drive motor as the input of the speed controller to control the speed of the drive motor, thereby achieving speed control facing the elevator car.

[0098] In step S1, the mathematical model that reflects the dynamic characteristics of the rope is constructed by using a mechanism modeling approach. The model parameters in the mathematical model are functions of the rope length, the speed of the elevator car, the load on the elevator car, and the torque current and rotor angular velocity of the drive motor. The specific values ​​of the model parameters are determined by test data.

[0099] Preferably, the elevator drive control method further includes step S5, which monitors the difference between the response signal of the mathematical model with the input signal of the rope as input and the response signal of the rope. When the difference exceeds a threshold, the model parameters are calculated based on the input signal of the rope and the response signal of the rope during elevator operation, and the model parameters are updated using the calculation results.

[0100] Example 4

[0101] The difference between this embodiment and embodiment 3 is that in step S1, the dynamic characteristics of the rope are modeled using a modeling method based on test data. The other features are basically the same as those in embodiment 3. The differences are further explained below.

[0102] In step S1, the dynamics of the rope are modeled by a modeling method based on test data to obtain a mathematical model based on test data. The modeling method includes at least one of black box system identification, neural network modeling, fuzzy model modeling, deep learning, and machine learning. The test data includes at least the input signal and response signal of the rope.

[0103] like Figure 5 As shown, an exemplary rope modeling step is as follows:

[0104] Step S11: Determine the influencing factors affecting the dynamic characteristics of the rope, and the manner in which the influencing factors affect the dynamic characteristics of the rope;

[0105] Step S12: Determine the value range of the influencing factor based on the influencing method;

[0106] Step S13: Determine the test conditions based on the influence method and the value range;

[0107] Step S14: Based on the test conditions, test data of the external factors are obtained.

[0108] Step S15: Establish the mathematical model based on the test data.

[0109] Preferably, the elevator drive control method further includes step S5, monitoring the difference between the response signal of the mathematical model with the input signal of the rope as input and the response signal of the rope. When the difference exceeds a threshold, the monitoring unit outputs a start command to start the modeling subunit to remodel the mathematical model using the current new test data.

Claims

1. An elevator drive control system, characterized in that, include: The car speed command generation unit is used to generate elevator car speed command values; The car speed detection unit is used to detect the speed at which the elevator car moves and obtain the car speed. The first subtractor is used to calculate the difference between the elevator car speed command value and the car speed to obtain the car speed error; A preprocessor is used to convert the car speed error into the drive motor speed error; A drive motor speed controller, which takes the drive motor as the controlled object, takes the speed error of the drive motor as its input, and outputs a current command value; The drive motor current detection unit is used to detect the current of the drive motor and obtain the motor current. The second subtractor is used to calculate the difference between the current command value and the motor current to obtain the current error; A drive motor current controller, which takes the current error as input and outputs the desired stator voltage; The preprocessor is configured as the inverse of a mathematical model that reflects the dynamic characteristics of the rope, which describes the output generated at the end of the rope connected to the elevator car after an input is applied at the end of the rope connected to the elevator drive sheave.

2. The elevator drive control system as described in claim 1, characterized in that, The preprocessor further includes: The modeling sub-unit is used to model the dynamic characteristics of the rope and output a mathematical model describing the dynamic characteristics of the rope. The inverse subunit is used to perform the inverse operation on the mathematical model to obtain the inverse of the mathematical model.

3. The elevator drive control system as described in claim 2, characterized in that, The modeling subunit uses a mechanism modeling approach to obtain the mathematical model. The model parameters in the mathematical model are functions of the rope length, elevator car speed, elevator car load, and the torque current and rotor angular velocity of the drive motor. The specific values ​​of the model parameters are determined by test data.

4. The elevator drive control system as described in claim 3, characterized in that, The system also includes: The updating unit is used to calculate the model parameters based on the input signal and response signal of the rope during elevator operation, and to update the model parameters using the calculation results; The input signals are the elevator car load, the rope length, and the torque current and rotor angular velocity of the drive motor; the response signal is the elevator car speed.

5. The elevator drive control system as described in claim 4, characterized in that, The system also includes: The monitoring unit is used to monitor the difference between the response signal of the mathematical model, which takes the input signal of the rope as input, and the response signal of the rope. When the difference exceeds a threshold, the monitoring unit outputs a start command to start the update unit to perform the update function.

6. The elevator drive control system as described in claim 2, characterized in that, The modeling subunit models the dynamics of the rope using a test data-based modeling method to obtain the mathematical model based on the test data. The modeling method includes at least one of black box system identification, neural network modeling, fuzzy model modeling, deep learning, and machine learning. The test data includes at least the input signal and response signal of the rope.

7. The elevator drive control system as described in claim 6, characterized in that, The system also includes: The monitoring unit monitors the difference between the response signal of the mathematical model, which takes the input signal of the rope as input, and the response signal of the rope. When the difference exceeds a threshold, the monitoring unit outputs a start command to initiate the modeling subunit to remodel the mathematical model using the current new test data.

8. The elevator drive control system as described in claim 6, characterized in that, The modeling subunit models the rope using the following steps: Step T1: Determine the factors affecting the dynamic characteristics of the rope, and the ways in which the factors affect the dynamic characteristics of the rope; Step T2: Determine the value range of the influencing factor based on the influencing method; Step T3: Determine the test conditions based on the influence method and the value range; Step T4: Based on the test conditions, obtain test data on external factors; Step T5: Establish the mathematical model based on the test data.

9. The elevator drive control system as described in claim 1, characterized in that, The inverse model of the rope's dynamics is directly established using a modeling method based on test data. This modeling method includes at least one of the following: black box system identification, neural network modeling, fuzzy model modeling, deep learning, and machine learning. The test data includes at least the rope's input signal and response signal.

10. The elevator drive control system as described in claim 6 or 9, characterized in that, The test data includes the length of the rope, the speed of the elevator car, the load on the elevator car, and the torque current and rotor angular velocity of the drive motor.

11. The elevator drive control system as described in claim 9, characterized in that, The preprocessor establishes the inverse of the mathematical model of the rope using the following steps: Step T1: Determine the factors affecting the dynamic characteristics of the rope, and the ways in which the factors affect the dynamic characteristics of the rope; Step T2: Determine the value range of the influencing factor based on the influencing method; Step T3: Determine the test conditions based on the influence method and the value range; Step T4: Based on the test conditions, obtain test data on external factors; Step T5: Establish the inverse of the mathematical model of the rope based on the test data.

12. An elevator drive control method for an elevator drive control system as described in any one of claims 1-11, characterized in that: By using the inverse of the mathematical model of the rope, the dynamic characteristics of the rope are compensated by processing the speed error of the elevator car movement into the rotor angular velocity error of the drive motor. This enables the drive motor speed controller, which controls the drive motor as the controlled object, to achieve speed regulation control of the elevator car. The rope refers to the rope located between the drive sheave and the elevator car.

13. The elevator drive control method as described in claim 12, characterized in that, The elevator drive control method includes the following steps: Step S1: Construct a mathematical model that reflects the dynamic characteristics of the rope, and then obtain the inverse of the mathematical model; Step S2: Design a speed control system with the drive motor as the controlled object to obtain a speed controller for the drive motor. Step S3: Use the inverse of the mathematical model to convert the car speed error into the drive motor speed error; Step S4: Use the speed error of the drive motor as the input of the speed controller to control the speed of the drive motor, thereby achieving speed control facing the elevator car.

14. The elevator drive control method as described in claim 13, characterized in that: Step S1 uses a mechanism modeling approach to obtain the mathematical model. The model parameters in the mathematical model are functions of the rope length, elevator car speed, elevator car load, and the torque current and rotor angular velocity of the drive motor. The specific values ​​of the model parameters are determined by test data.

15. The elevator drive control method as described in claim 14, characterized in that: The elevator drive control method further includes step S5, which monitors the difference between the response signal of the mathematical model with the input data of the rope as input and the rope response signal. When the difference exceeds a threshold, the model parameters are calculated based on the input signal of the rope and the response signal of the rope during elevator operation, and the model parameters are updated using the calculation results.

16. The elevator drive control method as described in claim 13, characterized in that: In step S1, the dynamics of the rope are modeled using a modeling method based on test data to obtain the mathematical model based on the test data. The modeling method includes at least one of black box system identification, neural network modeling, fuzzy model modeling, deep learning, and machine learning. The test data includes at least the input signal and response signal of the rope.

17. The elevator drive control method as described in claim 16, characterized in that: The elevator drive control method further includes step S5, which monitors the difference between the response signal of the mathematical model, which takes the input data of the rope as input, and the response signal of the rope. When the difference exceeds a threshold, the monitoring unit outputs a start command to start the modeling subunit to remodel the mathematical model using the current new test data.

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