Elevator drive control system

Abstract

The application discloses an elevator drive control system, comprising a dynamic torque controller, a static torque controller, a current command generator and a current controller; the dynamic torque controller generates a dynamic torque command according to the change of a speed command; the static torque controller generates a static torque command according to the tracking error of the actual speed of a car to the speed command, and the static torque command is used to eliminate the tracking error of the actual speed of the car to the speed command on the basis of the dynamic torque command; the current command generator is used to generate and output a current command of a drive motor according to the dynamic torque command and the static torque command; and the current controller is used to control the drive elevator according to the current command and the actual current of the drive motor, so that the actual current of the drive motor tracks the current command. The application can realize high-performance control of the drive motor of the elevator under the condition that transmission delay exists in the transmission of the detection information of the elevator car from the car to the control cabinet.

Description

Technical Field

[0001] This invention relates to the field of elevator technology, and more specifically to an elevator drive control system. Background Technology

[0002] Existing elevator drive systems typically employ a dual closed-loop control method involving speed and current. In the speed loop, the connection between the drive motor rotor and the elevator car is usually treated as a rigid connection. The ratio between the linear velocity of the elevator car and the angular velocity of the drive motor rotor is calculated using factors such as the radius of the drive wheel rotating synchronously with the drive motor rotor and the elevator's winding path. This ratio is then used to convert a given elevator car speed command into a drive motor rotor angular velocity command. The speed controller then uses this rotor angular velocity command and the detected rotor angular velocity value to implement closed-loop control of the drive motor rotor's angular velocity, ensuring that the detected rotor angular velocity value tracks the rotor angular velocity command, and outputting the drive motor's torque current command. In the current loop, the current controller typically uses the torque current command output from the speed controller and the detected stator current value of the drive motor to implement closed-loop control of the drive motor's current, ensuring that the detected stator current value (which is then transformed to obtain the actual torque current value) tracks the torque current command.

[0003] In reality, speed control in elevator drive control targets the speed of the elevator car. Precise control of the car's movement speed ensures smooth operation and accurate stopping. Existing technology treats the connection between the elevator car and the drive motor rotor as a rigid connection to achieve the conversion between them. However, flexible connections between the elevator car and the drive motor rotor (such as steel ropes or belts) typically possess a certain degree of elasticity and tensile strength. Therefore, the actual tensile strength varies depending on the length and stress of the flexible connection, and slippage between the flexible connection and the drive wheel is inevitable. This introduces errors into the conversion of car position / speed to the drive motor rotor, especially for elevators with large lifting heights and heavy loads, particularly when the elevator car is far from the drive wheel. This makes the performance of traditional drive control based on the rotor angular velocity of the drive motor unsatisfactory when applied to elevators with large lifting heights and heavy loads. Therefore, to improve the drive control performance of elevators with large lifting heights and heavy loads, it is necessary to directly control the elevator car's speed, rather than the existing indirect control achieved by controlling the rotor angular velocity of the drive motor. To directly control the elevator car's speed, it is first necessary to directly detect the elevator car's speed. This can be achieved using elevator car absolute position detection technology, which has matured and gained wider application in recent years, such as CN201810194044.0 and CN201580067931.6.

[0004] On the other hand, for elevators with large lifting heights, the traveling cable is very long. This poses a risk that the traveling cable might come into contact with other equipment in the hoistway during significant building swaying caused by earthquakes, strong winds, or other factors. Furthermore, the weight of the traveling cable becomes substantial due to the large lifting height. To address these issues, traveling cable-free technologies have emerged, such as CN201010154575.0, CN201980094886.1, and CN201010154575.0. However, existing traveling cable-free solutions primarily focus on solving the power supply problem of the elevator car, without addressing the information transmission issue between the elevator car and the control cabinet in the absence of a traveling cable. To address this issue, CN201880099563.7 proposes using wireless communication between the elevator car and the control cabinet to solve the information transmission problem when a traveling cable is not available. However, when using wireless communication, varying degrees of information transmission delays are unavoidable due to network congestion and other factors. Of course, even for elevators that use wired communication instead of elevators without traveling cables, the detection results of the elevator car's moving speed will still experience transmission delays during the transmission process from the elevator car to the control cabinet due to network congestion.

[0005] Therefore, for elevators with large lifting heights, direct control of the elevator car is necessary to improve its control performance. This requires transmitting the absolute position detection results of the elevator car (detected by a device located within the car) to a control cabinet, typically located in the machine room, so that the elevator drive control system within the control cabinet can implement drive control, including a speed loop. However, the transmission delay between the car and control cabinet for the car speed (or car position) detection results means that the elevator drive control system cannot obtain the real-time speed of the elevator car. Thus, how to achieve direct control of the elevator car's speed without obtaining its real-time speed becomes a technical problem that needs to be solved. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention provides an elevator drive control system, including a dynamic torque controller, a static torque controller, a current command generator, and a current controller;

[0007] The torque controller generates a torque command based on the change in speed command; the torque command refers to the torque output by the drive motor required to realize the change in the motion state of the elevator in response to the change in speed command.

[0008] The static torque controller generates a static torque command based on the tracking error of the actual car speed relative to the speed command. The static torque command refers to the torque that the drive motor needs to output to eliminate the tracking error of the actual car speed relative to the speed command or the remaining part after removing the random quantity from the tracking error, based on the dynamic torque command.

[0009] The current command generator is used to generate and output the current command for the drive motor based on the dynamic torque command and the static torque command.

[0010] The current controller is used to control the elevator according to the current command and the actual current of the drive motor, so that the actual current of the drive motor tracks the current command.

[0011] Preferably, the elevator drive control system further includes: a receiver, used to receive in real time the detection results detected by the car detection device installed on the elevator car and output the detection results, the detection results including the actual position and speed of the elevator car, and the corresponding sending time and receiving time, the sending time being the time when the car detection device sends the actual position and speed of the car to the receiver after detecting them, and the receiving time being the time when the receiver receives the detection results from the car detection device; the torque controller determines the speed command at the receiving time based on the receiving time, the sending time, and the elevator car position at the sending time, and generates the torque command based on the speed command at the receiving time.

[0012] Preferably, the elevator drive control system further includes a speed command determiner, used to determine a speed command corresponding to the received moment and send it to the dynamic torque controller or the static torque controller; the speed command determiner determines the speed command at the received moment according to the following steps:

[0013] Step S1: Determine the first point in the speed graph corresponding to the sending time or the elevator car position corresponding to the sending time based on the car position at the sending time. The speed graph is a curve formed with the car position as the horizontal axis and the speed command of the car movement as the vertical axis.

[0014] Step S2: Calculate the time difference between the receiving time and the sending time, and use it as the transmission delay of the detection result of the car detection device in the process of transmitting the detection result from the car detection device to the receiver;

[0015] Step S3: Calculate the distance the elevator car travels during the delay time based on the first point, the speed graph, and the transmission delay;

[0016] Step S4: Determine the position of the second car corresponding to the receiving time based on the first point and the car's moving distance;

[0017] Step S5: Determine the speed command corresponding to the receiving time based on the second car position and the speed graph.

[0018] Preferably, the torque controller further includes: a first module for determining the change in speed command corresponding to the receiving time; and a second module for generating a locking torque based on the change in speed command corresponding to the receiving time.

[0019] Preferably, the first module includes a subtraction unit and an integration unit, the second module includes a proportional unit, and the subtraction unit calculates the difference between the speed command and the output of the integration unit and uses it as its output; the proportional unit multiplies the output of the subtraction unit by a gain and uses the resulting product as its output; the integration unit integrates the output of the proportional unit and uses the integration result as its output; the torque controller uses the output of the proportional unit as the torque command.

[0020] Preferably, the torque controller also outputs the output of the integral unit as the speed command output at the receiving moment.

[0021] Preferably, the static torque controller generates a first static torque command corresponding to the sending time based on the difference between the speed command at the sending time and the actual speed of the car, and outputs the first static torque command as the static torque command.

[0022] Preferably, the static torque controller generates a second static torque based on the difference between the speed command received at the moment of receipt and the actual speed of the car, and outputs the second static torque as the static torque command.

[0023] Preferably, the static torque controller includes a subtraction module and a control module; the subtraction module calculates the difference between the speed command and the actual speed of the car and uses it as a tracking error; the control module directly generates a static torque command output based on the tracking error, or generates the static torque command based on the remaining part obtained after removing random quantities from the tracking error.

[0024] Preferably, when the control module generates a static torque command based on the remaining portion obtained after removing random quantities from the tracking error, the control module generates the static torque command by continuously accumulating control output or directly estimating persistent disturbances.

[0025] The control module obtains its output using any of the following methods:

[0026] Method 1: Use a PI control law and only use the I control output as the static torque command;

[0027] Method 2: Employ an active disturbance rejection control law and use only the extended state observer's total disturbance estimation result as the static moment command;

[0028] Method 3: Use an unknown input observer and use the observation results as the static moment command;

[0029] Method 4: Use a PI control law and use a combination of P control and I control as the static torque command.

[0030] Preferably, in the third method, the combination is the product of the P control output and the preset coefficient β and the sum of the I control output, where 0≤β≤1; and when Δt=0, β=1; the larger Δt is, the smaller β is, where Δt is the transmission delay.

[0031] Preferably, the elevator drive control system further includes an alarm, used to output an alarm signal when the tracking difference between the actual speed of the car and the speed command exceeds a threshold.

[0032] Preferably, the static torque controller includes a subtraction module, a control module, a determination module, and a correction module; the subtraction module calculates the difference between the speed command and the actual speed of the car and uses it as the tracking error;

[0033] The control module generates a second static torque command directly based on the tracking error, or generates a second static torque command based on the remaining part obtained after removing random quantities from the tracking error.

[0034] The determining module determines the variation pattern of the second static torque command based on historical data.

[0035] The correction module corrects the second static torque command according to the change pattern of the second static torque command, and outputs the correction result as the static torque command corresponding to the receiving time.

[0036] Preferably, the determining module performs data fitting on the historical data of the second static torque command and outputs the fitting result as the change law, and the correcting module converts the second static torque command corresponding to the receiving time in the curve result into a static torque command corresponding to the receiving time and outputs it.

[0037] Preferably, the correction module calculates the correction amount based on the variation law of the second static torque command, and outputs the sum of the correction amount and the second static torque command as the static torque command corresponding to the receiving time.

[0038] Preferably, the correction module calculates the correction amount according to the variation law of the second static torque command, and adds the product of the correction amount and the preset coefficient α to the sum of the second static torque commands as the static torque command corresponding to the receiving time; and the larger Δt is, the smaller the preset coefficient α is, where Δt is the transmission delay.

[0039] Compared with the prior art, the present invention can achieve high-performance control of elevator drive motor even when there is a transmission delay in the transmission of elevator car detection information from the car to the control cabinet. Attached Figure Description

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0041] Figure 1 This is a schematic diagram of the elevator drive control system structure in Example 1;

[0042] Figure 2 This is a schematic diagram of the elevator drive control system structure in Example 2;

[0043] Figure 3 This is a schematic diagram of the torque controller structure in Example 3;

[0044] Figure 4 This is a schematic diagram of the elevator drive control system structure in Example 4. Detailed Implementation

[0045] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and the details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art.

[0046] Example 1

[0047] like Figure 1 As shown, this embodiment provides an elevator drive control system, including a dynamic torque controller, a static torque controller, a current command generator, and a current controller;

[0048] The torque controller generates a torque command based on the change in speed command; the torque command refers to the torque output by the drive motor required to realize the change in the motion state of the elevator in response to the change in speed command.

[0049] The static torque controller generates a static torque command based on the tracking error of the car's actual speed relative to the speed command. The static torque command refers to the torque required to drive the motor to output torque based on the dynamic torque command, in order to eliminate the tracking error of the car's actual speed relative to the speed command or the remaining part after removing random quantities from the tracking error. The dynamic torque controller determines the speed command at the time of reception based on the receiving time, the sending time, and the elevator car position at the sending time, and generates the dynamic torque command based on the speed command at the time of reception.

[0050] The current command generator is used to generate and output the current command for the drive motor based on the dynamic torque command and the static torque command. The torque command is converted into a current command. For a PMSM, the torque and q-axis current are proportional. Therefore, this conversion involves multiplying the sum of the torques from the dynamic torque command and the static torque command by a proportional coefficient to obtain the current command.

[0051] The current controller is used to control the elevator according to the current command and the actual current of the drive motor, so that the actual current of the drive motor tracks the current command.

[0052] Example 2

[0053] like Figure 2 As shown, the elevator drive control system of this embodiment, based on the structure in embodiment 1, further includes:

[0054] A receiver is used to receive and output the detection results from the car detection device installed on the elevator car in real time. The detection results include the actual position and speed of the elevator car, as well as the corresponding transmission and reception times. The transmission time refers to the moment when the car detection device detects the actual position and speed of the car and sends it to the receiver. The reception time refers to the moment when the receiver receives the detection results from the car detection device.

[0055] The car detection device communicates wirelessly with the receiver, while the receiver is connected to other components of the elevator drive control system located in the elevator control cabinet via a wired connection. The transmission delay between the receiver and other components of the elevator drive control system is negligible.

[0056] Example 3

[0057] This implementation further explains the power torque controller based on the aforementioned embodiments.

[0058] The elevator drive control system of this embodiment, especially the speed controller therein, aims to make the actual moving speed of the elevator car track its command pattern, that is, to minimize the error between the speed command and the speed detection value.

[0059] Since the elevator car is mainly subjected to two forces—gravity and the tension applied to the car by the drive motor via a flexible connection—according to Newton's second law, for the actual moving speed of the elevator car to track the change in speed command, the sum of the external forces applied to the car must be proportional to the car's acceleration. This indicates that the torque command output by the torque controller should be proportional to the derivative of the speed command (or the change in speed command). Therefore, the torque controller further includes: a first module for determining the change in speed command corresponding to the received time and a second module for generating the torque based on the change in speed command corresponding to the received time.

[0060] Figure 3 The diagram shows a preferred implementation of the first and second modules. In this implementation, the first module includes a subtraction unit and an integration unit, and the second module includes a scaling unit.

[0061] The subtraction unit calculates the difference between the speed command and the output of the integration unit, and uses it as its output;

[0062] The proportional unit takes the product obtained by multiplying the output of the subtraction unit by a gain as its output.

[0063] The integration unit integrates the output of the proportional unit and uses the integration result as its output.

[0064] The torque controller uses the output of the proportional unit as the torque command.

[0065] Preferably, the torque controller also outputs the integral result of the integral unit as an ideal speed command.

[0066] Example 4

[0067] This embodiment further explains the torque controller based on implementation 3.

[0068] like Figure 4 As shown, the elevator drive control system of this embodiment, based on the structure in embodiment 2, further includes:

[0069] A speed command determiner is used to determine the speed command corresponding to the received moment and send it to the dynamic torque controller or the static torque controller.

[0070] The speed command determiner takes detection information from the receiver as input and a speed command as output, and the steps for determining the speed command at the receiving moment include:

[0071] Step S1: Determine the first point in the speed graph corresponding to the sending time or the elevator car position corresponding to the sending time based on the car position at the sending time. The speed graph is a curve formed with the car position as the horizontal axis and the speed command of the car movement as the vertical axis.

[0072] Step S2: Calculate the time difference between the receiving time and the sending time, and use it as the transmission delay of the detection result of the car detection device in the process of transmitting the detection result from the car detection device to the receiver;

[0073] Step S3: Calculate the distance the elevator car travels during the delay time based on the first point, the speed graph, and the transmission delay;

[0074] Step S4: Determine the position of the second car corresponding to the receiving time based on the first point and the car's moving distance;

[0075] Step S5: Determine the speed command corresponding to the receiving time based on the second car position and the speed graph. It should be noted that, including this embodiment and Embodiment 3, the receiving time when the elevator drive control system receives the detection result from the car detection device and the corresponding transmission delay Δt and implements speed control accordingly is k1. The sending time k2 is obtained by shifting the transmission delay Δt forward from k1, whereby the car detection device acquires its detection result and sends it to the receiver; that is, k2 = k1 - Δt.

[0076] The physical meaning of torque is as follows: when the elevator car is in a stable state (stationary state or constant speed state), and we want it to continue to change from that stable state along the speed command pattern, without considering the external disturbances that may occur during the state change process (of course, the starting point of the speed command pattern should be the same as the speed of the elevator car in the stable state), as long as we continue to implement the torque, the moving speed of the car will track the speed command pattern. That is, the torque is used to realize the state change of the elevator car.

[0077] Example 5

[0078] This embodiment provides a further detailed description of the static torque controller based on the aforementioned embodiments.

[0079] In this embodiment, the static torque is the torque output by the drive motor required to eliminate or suppress the tracking error between the actual speed of the elevator car and the speed command caused by external interference, based on the dynamic torque command. The static torque controller generates a static torque command output based on the difference between the speed command and the actual speed of the car. The speed command here can be the speed command at the sending time or the speed command at the receiving time; it can be the same speed command as the input of the dynamic torque controller (corresponding to the receiving time), or it can be the ideal speed command output by the dynamic torque controller in Embodiment 3 (also corresponding to the receiving time, but with more gradual fluctuations compared to the former), such as... Figure 4 As shown by the dashed line.

[0080] When a speed command at the time of transmission is used, the static torque controller generates a first static torque command corresponding to the time of transmission based on the difference between the speed command at the time of transmission and the actual speed of the car, and outputs the first static torque command as the static torque command.

[0081] When a speed command at the moment of reception is used, the static torque controller generates a second static torque based on the difference between the speed command at the moment of reception and the actual speed of the car, and outputs the second static torque as the static torque command. The speed command at this time comes from the output of the integral unit of the dynamic torque controller.

[0082] The actual speed of the car corresponds to the detection time, which is usually very close to the transmission time and can be ignored. The actual speed of the car received by the receiver at the receiving time is still the actual speed corresponding to the detection time; it's just that the actual speed corresponding to the detection time is received after a transmission delay. The receiver cannot obtain the true actual speed corresponding to the receiving time because, although the speed has been detected by the detection device, it has not yet been transmitted to the receiver. In other words, the actual speed of the car received by the receiver is always the actual speed corresponding to the transmission time. Therefore, the corresponding time of the actual car speed is no longer specified.

[0083] The static torque controller includes a subtraction module and a control module; the subtraction module calculates the difference between the speed command and the actual speed of the car and uses it as a tracking error; the control module directly generates a static torque command output based on the tracking error.

[0084] Case 1: The control module generates the first static torque command based on the difference between the speed command sent at the time and the actual speed of the car.

[0085] Since at receiving time k1, only the speed detection result (i.e., the actual speed of the car) v(k2) at transmitting time k2 is available, and the speed detection result v(k1) at receiving time k1 is not available, the static torque controller calculates the difference between the speed command Vref(k2) at transmitting time k2 and the speed detection result v(k2), and generates the static torque T2(k2) corresponding to transmitting time k2 based on this difference. Assuming that the difference between the static torque T2(k2) at transmitting time k2 and the static torque T2(k1) at receiving time k1 that we actually need is very small, T2(k2) can be used to replace the static torque T2(k1) corresponding to receiving time k1. The rationale for the substitution of T2(k2) for T2(k1) is explained as follows:

[0086] During the movement of the elevator car, it is subject to two main types of external disturbances: one is a continuous random disturbance with a generally small amplitude, and the other is a relatively large continuous disturbance (such as: the average friction between the guide rail and the guide shoe, while the aforementioned random disturbance is the change in actual friction relative to this average value; the deviation of the pre-applied starting torque caused by the detection error of the elevator car's weighing device; the air resistance during the movement of the car, etc.).

[0087] Regarding random errors, since we cannot obtain the elevator car's speed detection value at the receiving time k1—the actual speed of the car—we cannot know about these random disturbances. Considering that the random disturbances are roughly located on both sides of 0 (i.e., they are both positive and negative, and the integral is approximately zero), the impact of random disturbances on the elevator car's moving speed is also correspondingly positive and negative. The positive and negative effects cancel each other out to a certain extent. Therefore, we do not control the impact of random disturbances on the elevator car's moving speed here.

[0088] For persistent disturbances, the amplitude of the persistent disturbance at receiving time k1 is approximately equal to that at transmitting time k2 (or the trend of change is approximately the same as the previous trend—air resistance changes during acceleration and deceleration, but the change in controller resistance corresponding to the same change in speed is approximately the same).

[0089] Scenario 2: The control module generates a second static torque command based on the difference between the speed command received at time k1 and the actual speed of the car.

[0090] Since the speed detection result (i.e., the actual car speed) obtained at receiving time k1 is the speed detected at sending time k2, the static torque controller actually generates a static torque T2(k1) corresponding to receiving time k1 using the speed command at receiving time k1 and the actual car speed at sending time k2. The rationale is that the torque required to correspond to the change in speed command has already been generated by the dynamic torque controller and will serve as feedforward. Therefore, the static torque only needs to address the invariant part of the speed command after removing the change. Thus, in the presence of a dynamic torque controller, the static torque controller can approximately consider the speed command at receiving time k1 to be equal to the speed command at sending time k2. This allows us to assume that the static torque controller also generates the second static torque command based on the difference between the speed command at sending time and the actual car speed. Referring to the explanation in Case 1, the rationality of the aforementioned processing can be confirmed.

[0091] Having completed the above analysis of random errors and persistent disturbances, the control module can use any controller to directly generate a static torque command output based on the tracking error. That is, by implementing control with the tracking error as input and the static torque as output, the actual speed of the elevator car can be made to track the car speed command, thereby achieving high-performance control of the elevator drive motor.

[0092] In summary, as long as the elevator car does not experience occasional large-scale disturbances during its movement, the output of the control module can be used as T2(k2), because the output of the control module is the torque we really need to overcome the continuous disturbances.

[0093] Preferably, from an engineering practice perspective, the speed tracking error at the sending time k2 should be continuously monitored, and an alarm signal should be output when the tracking difference between the actual car speed and the speed command exceeds a threshold.

[0094] Example 6

[0095] This embodiment, also based on embodiments 1 to 4, provides a further detailed description of the static torque controller. This embodiment is similar to embodiment 5; the differences will be explained below.

[0096] In this embodiment, the static torque command refers to the torque required to drive the motor, which is the remaining portion obtained after removing random quantities from the tracking error between the actual car speed and the speed command, based on the dynamic torque command. The control module in the static torque controller generates the static torque command based on the remaining portion obtained after removing random quantities from the tracking error.

[0097] In Example 5, the static torque controller uses speed error as input. However, as analyzed in Example 5 regarding random errors, random errors in the speed error have no substantial significance for the static torque controller in generating static torque. In some cases, they may even lead to inappropriate components in the generated static torque, resulting in a decrease in the final elevator drive control performance. For example, when there is a relatively large random error in the speed error, and the static torque controller does not have sufficient disturbance suppression capability (e.g., excessive amplification effect of random disturbances). To solve this problem, the static torque controller in this embodiment also includes a subtraction module and a control module. The subtraction module calculates the difference between the speed command and the actual car speed and uses it as the tracking error. However, the control module generates the static torque command based on the remaining part obtained after removing the random quantity from the tracking error, and the control module needs to have the ability to estimate the third torque applied to eliminate persistent disturbances.

[0098] Preferably, the control module uses techniques such as filters, notch filters, and moving averages to remove random quantities from the tracking error to obtain the remaining portion.

[0099] After removing the random quantity from the tracking error to obtain the remaining portion, the control module generates a static torque command based on this remaining portion. To this end, the control module generates the static torque command by continuously accumulating the control output or directly estimating the persistent disturbance. Specifically, the control module generates the static torque command using either of the following methods:

[0100] Method 1: Use a PI control law and only use the I control output as the static torque command;

[0101] Method 2: Employ an active disturbance rejection control law and use only the extended state observer's total disturbance estimation result as the static moment command;

[0102] Method 3: Use an unknown input observer and use the observation results as the static moment command;

[0103] Method 4: Use a PI control law and use a combination of P control and I control as the static torque command.

[0104] In the third method, the combination is the product of the P control output and the preset coefficient β and the sum of the I control output, where 0≤β≤1; and when Δt=0, β=1; the larger Δt is, the smaller β is, where Δt is the transmission delay.

[0105] Example 7

[0106] This embodiment, also based on embodiments 1 to 4, provides a further detailed description of the static torque controller. This embodiment is similar to embodiment 5; the differences will be explained below.

[0107] The static torque controller in this embodiment includes a subtraction module, a control module, a determination module, and a correction module; the subtraction module calculates the difference between the speed command and the actual speed of the car and uses it as the tracking error;

[0108] The control module generates a second static torque command directly based on the tracking error, or generates a second static torque command based on the remaining part obtained after removing random quantities from the tracking error.

[0109] The determining module determines the variation pattern of the second static torque command based on historical data.

[0110] The correction module corrects the second static torque command according to the change pattern of the second static torque command, and outputs the correction result as the static torque command corresponding to the receiving time.

[0111] The determining module performs data fitting on the historical data of the second static torque command and outputs the fitting result as the change law. The correcting module converts the second static torque command corresponding to the receiving time in the curve result into a static torque command corresponding to the receiving time and outputs it.

[0112] The correction module calculates the correction amount based on the variation law of the second static torque command, and outputs the sum of the correction amount and the second static torque command as the static torque command corresponding to the receiving time.

[0113] The correction module calculates the correction amount according to the variation law of the second static torque command, and adds the product of the correction amount and the preset coefficient α to the sum of the second static torque commands as the static torque command corresponding to the receiving time; and the larger Δt is, the smaller the preset coefficient α is, where Δt is the transmission delay.

[0114] For α and β in Example 6, they both change with Δt. The larger Δt is, the lower the accuracy of the correction of T2 at time k1 based on α and β is, that is, the more likely it is to cause false correction. Therefore, α and β are used to weaken their correction effect.

[0115] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. An elevator drive control system, characterized in that, This includes a dynamic torque controller, a static torque controller, a current command generator, and a current controller; The torque controller generates a torque command based on the change in speed command; the torque command refers to the torque output by the drive motor required to realize the change in the motion state of the elevator in response to the change in speed command. The static torque controller generates a static torque command based on the tracking error of the actual car speed relative to the speed command. The static torque command refers to the torque that the drive motor needs to output to eliminate the tracking error of the actual car speed relative to the speed command or the remaining part after removing the random quantity from the tracking error, based on the dynamic torque command. The current command generator is used to generate and output the current command for the drive motor based on the dynamic torque command and the static torque command. The current controller is used to control the elevator according to the current command and the actual current of the drive motor, so that the actual current of the drive motor tracks the current command. The elevator drive control system also includes: The receiver is used to receive the detection results from the car detection device installed on the elevator car in real time and output the detection results. The detection results include the actual position and speed of the elevator car, as well as the corresponding sending time and receiving time. The sending time refers to the time when the car detection device sends the actual position and speed of the car to the receiver after detecting them. The receiving time refers to the time when the receiver receives the detection results from the car detection device. The torque controller determines the second car position at the receiving time based on the receiving time, the sending time, and the elevator car position at the sending time. It then determines the speed command corresponding to the receiving time based on the second car position and the speed graph, and generates the torque command based on the speed command at the receiving time. The speed graph is a curve formed with the car position as the horizontal axis and the speed command of the car movement as the vertical axis.

2. The elevator drive control system according to claim 1, characterized in that, The elevator drive control system also includes: A speed command determiner is used to determine the speed command corresponding to the received moment and send it to the dynamic torque controller or the static torque controller.

3. The elevator drive control system according to claim 2, characterized in that, The speed command determiner determines the speed command at the receiving time according to the following steps: Step S1: Determine the first point in the speed graph corresponding to the sending time or the elevator car position corresponding to the sending time based on the car position at the sending time. The speed graph is a curve formed with the car position as the horizontal axis and the speed command of the car movement as the vertical axis. Step S2: Calculate the time difference between the receiving time and the sending time, and use it as the transmission delay time of the detection result of the car detection device in the process of being transmitted from the car detection device to the receiver; Step S3: Calculate the distance the elevator car travels during the transmission delay time based on the first point, the speed graph, and the transmission delay time. Step S4: Determine the position of the second car corresponding to the receiving time based on the first point and the car's moving distance; Step S5: Determine the speed command corresponding to the receiving time based on the second car position and the speed graph.

4. The elevator drive control system according to claim 1, characterized in that, The torque controller further includes: The first module is used to determine the change in the speed command corresponding to the received time. The second module is used to generate the locking torque based on the change in the speed command corresponding to the received time.

5. The elevator drive control system according to claim 4, characterized in that, The first module includes a subtraction unit and an integration unit, and the second module includes a scaling unit. The subtraction unit calculates the difference between the speed command and the output of the integration unit, and uses it as its output; The proportional unit takes the product obtained by multiplying the output of the subtraction unit by a gain as its output. The integration unit integrates the output of the proportional unit and uses the integration result as its output. The torque controller uses the output of the proportional unit as the torque command.

6. The elevator drive control system according to claim 5, characterized in that, The torque controller also outputs the output of the integral unit as the speed command at the receiving moment.

7. The elevator drive control system according to claim 3, characterized in that, The static torque controller generates a first static torque command corresponding to the sending time based on the difference between the speed command at the sending time and the actual speed of the car, and outputs the first static torque command as the static torque command.

8. The elevator drive control system according to claim 3, characterized in that, The static torque controller generates a second static torque based on the difference between the speed command received at the moment of receipt and the actual speed of the car, and outputs the second static torque as the static torque command.

9. The elevator drive control system according to claim 7 or 8, characterized in that, The static torque controller includes a subtraction module and a control module; The subtraction module calculates the difference between the speed command and the actual speed of the car and uses it as the tracking error; The control module can directly generate a static torque command output based on the tracking error, or generate the static torque command based on the remaining part obtained after removing random quantities from the tracking error.

10. The elevator drive control system according to claim 9, characterized in that, When the control module generates a static torque command based on the remaining part obtained after removing random quantities from the tracking error, the control module generates the static torque command by continuously accumulating control output or directly estimating the continuous disturbance.

11. The elevator drive control system according to claim 10, characterized in that, The control module obtains its output using any of the following methods: Method 1: Use a PI control law and only use the I control output as the static torque command; Method 2: Employ an active disturbance rejection control law and use only the extended state observer's total disturbance estimation result as the static moment command; Method 3: Use an unknown input observer and use the observation results as the static moment command; Method 4: Use a PI control law and use a combination of P control and I control as the static torque command.

12. The elevator drive control system according to claim 11, characterized in that, In the fourth method, the combination is the product of the P control output and the preset coefficient β and the sum of the I control output, where 0≤β≤1; and when Δt=0, β=1; the larger Δt is, the smaller β is, where Δt is the transmission delay time.

13. The elevator drive control system according to claim 1, characterized in that, The elevator drive control system also includes: An alarm is used to output an alarm signal when the difference between the actual speed of the car and the speed command exceeds a threshold.

14. The elevator drive control system according to claim 7 or 8, characterized in that, The static torque controller includes a subtraction module, a control module, a determination module, and a correction module; the subtraction module calculates the difference between the speed command and the actual speed of the car and uses it as the tracking error; The control module generates a second static torque command directly based on the tracking error, or generates a second static torque command based on the remaining part obtained after removing random quantities from the tracking error. The determining module determines the variation pattern of the second static torque command based on historical data. The correction module corrects the second static torque command according to the change pattern of the second static torque command, and outputs the correction result as the static torque command corresponding to the receiving time.

15. The elevator drive control system according to claim 14, characterized in that, The determining module performs data fitting on the historical data of the second static torque command and outputs the fitting result as the change law. The correcting module converts the second static torque command corresponding to the receiving time in the curve result into a static torque command corresponding to the receiving time and outputs it.

16. The elevator drive control system according to claim 14, characterized in that, The correction module calculates the correction amount based on the variation law of the second static torque command, and outputs the sum of the correction amount and the second static torque command as the static torque command corresponding to the receiving time.

17. The elevator drive control system according to claim 16, characterized in that, The correction module calculates the correction amount according to the variation law of the second static torque command, and adds the product of the correction amount and the preset coefficient α to the sum of the second static torque commands as the static torque command corresponding to the receiving time; and the larger Δt is, the smaller the preset coefficient α is, where Δt is the transmission delay time.

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