Elevator control device
By using the current information and unbalanced torque of the traction machine, the problem of not being able to identify the characteristic parameters of the motor in the prior art is solved, and parameter identification and control parameter adjustment without the torque detector are realized, which reduces the The software burdens and maintains constant control performance.
Patent Information
- Application Number
- CN202410026533.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-06-29
- Filing Date
- 2024-01-05
- Publication Date
- 2024-12-31
AI Technical Summary
The prior art cannot identify the characteristic parameters of the motor in systems without torque detectors, and the need to interfere with the observer results in an increase in the software burden.
The characteristic parameters of the traction machine are identified by using the current information supplied by the traction machine and the unbalanced torque generated by the weight difference between the car and the counterweight, and then the control parameters are adjusted.
It realizes the identification of the characteristic parameters of the traction machine without the need for a torque detector, reduces the software burden and maintains the constant control performance.
Smart Images
Figure CN119218842A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technology of a control device for an elevator. Background Art
[0002] Patent Document 1 discloses a method for identifying motor parameters using an estimation technique based on a disturbance observer in a motor control device. In this method, motor parameters are identified based on a disturbance estimation value of a disturbance observer, a q-axis current, a disturbance estimation value, and a torque detected by a torque detector.
[0003] Prior art literature
[0004] Patent Document 1: Japanese Patent Application Publication No. 2022-178401 Summary of the invention
[0005] However, the technique described in Patent Document 1 cannot identify characteristic parameters of a motor in a system without a torque detector. In addition, the technique described in Patent Document 1 has a problem that an estimation operation such as a disturbance observer is required, which increases the burden on software.
[0006] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a technology for identifying characteristic parameters of the hoisting machine using information on current supplied to the hoisting machine of an elevator, and optimizing control parameters used for controlling the hoisting machine.
[0007] The present invention provides a control device for an elevator, the elevator comprising: a car; a main rope, one end of which is connected to the car, and the other end of which is connected to a counterweight; and a traction machine, which hangs the main rope around a rope pulley to raise and lower the car, wherein the control device for the elevator comprises: a traction machine control unit, which uses control parameters to control the traction machine; and a parameter identification unit, which identifies characteristic parameters of the traction machine, the parameter identification unit is configured to use the current value flowing through the traction machine and the unbalanced torque generated by the weight difference between the car and the counterweight to identify the characteristic parameters, and the traction machine control unit is configured to set the control parameters based on the characteristic parameters.
[0008] Effects of the Invention
[0009] According to the technique of the present invention, it is possible to identify characteristic parameters of the hoisting machine using information on the current supplied to the hoisting machine of the elevator, and to optimize control parameters used for controlling the hoisting machine. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 This is a block diagram of an elevator according to Embodiment 1.
[0011] Figure 2This is a diagram showing an example of time changes in the q-axis current value and the rotation speed of the hoisting machine when the stationary holding control is executed in the elevator according to the first embodiment.
[0012] Figure 3 This is a flowchart showing a routine for the elevator control device according to the first embodiment to identify a torque constant.
[0013] Figure 4 It is a diagram showing an example of hardware resources of a control device.
[0014] Figure 5 This is a diagram showing another example of the hardware resources of the control device.
[0015] Figure 6 This is a diagram showing an example of a temporal change in the q-axis current value of the hoisting machine when the stationary holding control is executed in the elevator according to the second embodiment, depending on the car load.
[0016] Figure 7 This is a flowchart showing a routine for the elevator control device according to the second embodiment to identify a torque constant.
[0017] Figure 8 This is a diagram showing an example of time changes in the q-axis current value of the hoisting machine and the car position in the hoistway when the elevator according to Embodiment 3 continuously performs an ascending operation from the lowest floor to the highest floor and a descending operation from the highest floor to the lowest floor.
[0018] Fig. 9 This is a flowchart showing a routine for the elevator control device according to the third embodiment to identify a torque constant.
[0019] Fig.10 This is a diagram showing an example of time changes in the q-axis current value and the rotation speed of the hoisting machine when the stationary holding control is executed in the elevator according to the fourth embodiment.
[0020] Fig.11 This is a flowchart showing a routine for adjusting current control parameters by the elevator control device according to the fourth embodiment.
[0021] Description of symbols
[0022] 1: traction machine; 2: rotation sensor; 3: car; 4: counterweight; 5: main rope; 6: braking device; 7: weighing device; 8: current sensor; 9: power converter; 10: control device; 12: traction machine control unit; 14: parameter identification unit; 100: elevator; 102: processor; 104: memory; 106: processing circuit; 108: dedicated hardware. DETAILED DESCRIPTION
[0023] Hereinafter, the embodiments will be described with reference to the drawings. In addition, the same reference numerals are given to the common elements in each figure, and the repeated description is omitted.
[0024] Implementation Method 1
[0025] 1-1. Structure of elevator in Embodiment 1
[0026] Figure 1 1 is a block diagram of an elevator according to Embodiment 1. An elevator 100 according to Embodiment 1 is installed in a facility constituted by a building having a plurality of floors. A hoistway of the elevator 100 is installed in the facility. The hoistway is a space that is long in the vertical direction across a plurality of floors.
[0027] The elevator 100 includes a traction machine 1 , a rotation sensor 2 , a car 3 , a counterweight 4 , a main rope 5 , a brake device 6 , a weighing device 7 , a current sensor 8 , a power converter 9 , and a control device 10 as a main structure.
[0028] The hoisting machine 1 is installed at the upper part of the hoistway. The hoisting machine 1 has a sheave and a motor for rotating the sheave. The main rope 5 is hung around the sheave of the hoisting machine 1. The car 3 is connected to one end of the main rope. The counterweight 4 is connected to the other end of the main rope 5. The car 3 and the counterweight 4 are suspended in the hoistway in a bucket-like manner by the main rope 5. By rotating the sheave of the hoisting machine 1, the car 3 and the counterweight 4 are raised and lowered in the hoistway.
[0029] The weight of the counterweight 4 is adjusted based on the weight ratio of the rated capacity CP of the car 3, which is called the "balance ratio γ". For example, when the balance ratio γ is set to 50%, the weight of the counterweight 4 is adjusted to a value obtained by adding the weight of 50% of the rated capacity CP to the mass of the car 3.
[0030] The rotation sensor 2 detects the rotation position and rotation speed of the traction machine 1 by generating a pulse value corresponding to the rotation of the sheave. The rotation sensor 2 uses, for example, an encoder or a resolver that generates a signal corresponding to the rotation of the sheave. The detected rotation position and rotation speed are input to the control device 10 and used for position control and speed control of the traction machine 1.
[0031] The brake device 6 brakes the rotation of the hoisting machine 1 according to the brake command from the control device 10. The weighing device 7 measures the car load acting on the car 3. The car load measured by the weighing device 7 is input to the control device 10. The current sensor 8 detects the current value flowing through the hoisting machine 1. The current value detected by the current sensor 8 is input to the control device 10.
[0032] The power converter 9 applies a voltage to the hoisting machine 1 in accordance with a voltage command calculated by the control device 10. The power converter 9 is, for example, a PWM inverter.
[0033] As functions realized by executing a program by a processor, the control device 10 includes a hoisting machine control unit 12 and a parameter identification unit 14. The hoisting machine control unit 12 is a functional block for calculating a voltage command for controlling the hoisting machine 1. Typically, the hoisting machine control unit 12 forms a position control system and a speed control system based on the rotation position and rotation speed of the hoisting machine 1 detected by the rotation sensor 2. In addition, the hoisting machine control unit 12 forms a current control system based on the current value detected by the current sensor 8. The control gains of the position control system, the speed control system, and the current control system of the hoisting machine control unit 12 are adjusted based on the characteristic parameters of the hoisting machine 1 identified in the parameter identification unit 14.
[0034] The parameter identification unit 14 is a functional block for identifying the characteristic parameters of the hoisting machine 1. Typically, the parameter identification unit 14 uses the current command value received as the control command value from the hoisting machine control unit 12 and the current value detected by the current sensor 8 to identify the characteristic parameters. This process is hereinafter referred to as "identification processing". As a characteristic parameter, for example, the torque constant Kt is exemplified. The torque constant Kt is the generated torque per unit current generated by the hoisting machine 1. The characteristic parameters identified in the identification process are sent to the hoisting machine control unit 12. The hoisting machine control unit 12 adjusts the control parameters of the position control system, the speed control system, and the current control system according to the characteristic parameters.
[0035] 1-2. Overview of Identification Processing
[0036] Next, an overview of the identification process performed in the parameter identification unit 14 in the first embodiment is described. When the weight of the car 3 and the counterweight 4 is balanced, the load torque acting on the traction machine 1, that is, the unbalanced torque T1 generated by the weight difference between the car 3 and the counterweight 4 is 0. On the other hand, when the weight of the car 3 and the counterweight 4 is unbalanced, the unbalanced torque T1 acts on the traction machine 1 due to the weight difference between the car 3 and the counterweight 4. In the identification process, the parameter identification unit 14 uses the unbalanced torque T1 to calculate the torque constant Kt as a characteristic parameter.
[0037] When the mass of the car 3 when no load acts on the car 3 is M1, the mass of the counterweight 4 is M2, the gravitational acceleration is g, and the sheave diameter of the hoisting machine 1 is r, the unbalanced torque T1 can be expressed by the following equation (1).
[0038] T1=(M1-M2)×g×r...(1)
[0039] The mass M2 of the counterweight 4 can be rewritten as in the following equation (2) using the mass M1 of the car 3, the rated capacity CP of the car 3, and the balance ratio γ.
[0040] M2=M1+γ×CP...(2)
[0041] Based on equations (1) and (2), the unbalanced torque T1 can be expressed by the following equation (3). As shown in equation (3), if the balance ratio γ, the rated capacity CP, and the sheave diameter r of the hoisting machine 1 are known, the unbalanced torque T1 can be calculated as a known value.
[0042] T1=-γ×CP×g×r...(3)
[0043] The torque T2 generated by the hoisting machine 1 can be expressed by the following equation (4) using the q-axis current Iq of the hoisting machine 1 and the torque constant Kt.
[0044] T2=Kt×Iq...(4)
[0045] Here, when the hoisting machine control unit 12 releases the brake applied by the brake device 6 and performs feedback control on the torque T2 of the hoisting machine 1 so that the speed of the hoisting machine 1 becomes 0 (zero), the unbalanced torque T1 is balanced with the torque T2. Therefore, when the car 3 is stationary based on the stationary holding control, the torque constant Kt can be expressed as shown in the following formula (5).
[0046] Kt=T1 / Iq...(5)
[0047] Figure 2 1 is a diagram showing an example of the time change of the q-axis current value and the rotation speed of the hoisting machine 1 when the stationary holding control is performed in the elevator of Embodiment 1. In the example shown in the figure, when the brake device 6 is released from the state of braking by the brake device 6 so that the rotation speed of the hoisting machine 1 becomes 0, the hoisting machine 1 rotates due to the unbalanced torque T1. The hoisting machine control unit 12 performs the stationary holding control and generates the q-axis current Iq for causing the hoisting machine 1 to generate the torque T2 so that the rotation speed becomes 0. Then, when the rotation speed becomes 0, the q-axis current Iq becomes a fixed value, and the q-axis current Iq at this time becomes the stationary holding current that balances the torque T2 and the unbalanced torque T1. The parameter identification unit 14 substitutes the unbalanced torque T1 and the stationary holding current detected by the current sensor 8 into the formula (5) to identify the torque constant Kt. The identified torque constant Kt is sent to the hoisting machine control unit 12.
[0048] The hoisting machine control unit 12 uses the identified torque constant Kt to set the control gain, particularly the speed control gain, of the hoisting machine control unit 12. Thus, even when the characteristics of the hoisting machine 1 change due to temperature changes or aging, the control performance can be kept constant.
[0049] In addition, when the torque constant Kt is unknown, the torque constant Kt is pre-calculated using the rated torque, rated output, rated speed, and rated current recorded on the motor nameplate of the hoisting machine 1. The hoisting machine control unit 12 uses the calculated torque constant Kt to perform stationary holding control. Then, the parameter identification unit 14 can calculate the accurate torque constant Kt based on the actual q-axis current Iq of the hoisting machine 1 during the stationary holding control and the torque T2 acting on the hoisting machine 1.
[0050] Furthermore, a current for generating a torque having the same value as the unbalanced torque T1 may be supplied to the hoisting machine 1 before releasing the brake device 6. Such control can shorten the time until the rotation speed converges to 0 when the stationary holding control is performed.
[0051] 1-3. Specific Processing Executed by the Control Device in Embodiment 1
[0052] Figure 3 This is a flowchart showing a routine for identifying a torque constant by the elevator control device in Embodiment 1. In Embodiment 1, the control device 10 executes this routine when the car load is 0, that is, when no user is riding in the car 3. In this case, the unbalanced torque T1 can be calculated as a known quantity based on equation (3).
[0053] In step S100, the brake device 6 that is braking the hoisting machine 1 is released. When the brake is released, in step S102, a stationary holding control is performed to generate a torque T2 in the hoisting machine 1 so that the speed of the hoisting machine 1 becomes zero.
[0054] Next, in step S104, it is determined whether the rotation speed detected by the rotation sensor 2 is less than a reference value. The reference value here is, for example, 0. Alternatively, the reference value may be a value near 0. As a result, if it is not confirmed that the determination is established, the process returns to step S102 and the stationary holding control process is executed again. On the other hand, if it is confirmed that the determination is established, the process proceeds to step S106.
[0055] In step S106, the static holding current value is obtained. Here, the obtained current value may be subjected to filtering processing, or a value obtained by obtaining multiple data in the sampling cycle of the control device 10 and averaging the data may be obtained as the static holding current value. When the processing of step S106 is completed, the processing proceeds to step S108.
[0056] In step S108, the torque constant Kt is identified. Here, the torque constant Kt is calculated by substituting the stationary holding current value obtained in step S106 and the unbalanced torque T1, which is a known quantity, into equation (5).
[0057] As can be seen from the above description, according to the elevator 100 of Embodiment 1, the torque constant Kt, which is a characteristic parameter of the motor of the traction machine 1, can be identified using the static holding current detected during the execution of the static holding control. As a result, the control parameters of the traction machine control unit 12 can be made appropriate, and thus the control performance can be kept constant.
[0058] 1-4. Modifications
[0059] The elevator 100 according to the first embodiment may adopt the following modified forms.
[0060] 1-4-1. Hardware resources of the control device 10
[0061] Figure 4 1 is a diagram showing an example of hardware resources of the control device 10. The control device 10 includes a processing circuit 106 including a processor 102 and a memory 104 as hardware resources. The processing circuit 106 may include a plurality of processors 102. The processing circuit 106 may include a plurality of memories 104.
[0062] In the present embodiment, the traction machine control unit 12 and the parameter identification unit 14 represent the functions of the control device 10. The functions of the traction machine control unit 12 and the parameter identification unit 14 can be realized by software, firmware, or a combination of software and firmware described as a program. The program is stored in the memory 104. Alternatively, the program can also be recorded in a computer-readable recording medium. The control device 10 realizes the functions of the traction machine control unit 12 and the parameter identification unit 14 by executing the program stored in the memory 104 by the processor 102 (computer).
[0063] The processor 102 is also called a CPU (Central Processing Unit), a central processing device, a processing device, an arithmetic device, a microprocessor, a microcomputer or a DSP. As the memory 104, a semiconductor memory, a magnetic disk, a floppy disk, an optical disk, a compact optical disk, a mini disk or a DVD may also be used. The semiconductor memory that may be used includes a RAM, a ROM, a flash memory, an EPROM and an EEPROM.
[0064] Figure 5 FIG. 1 is a diagram showing another example of hardware resources of the control device 10. Figure 5 In the illustrated example, the control device 10 includes a processing circuit 106 including a processor 102 , a memory 104 , and dedicated hardware 108 . Figure 5An example is shown in which a part of the functions of the control device 10 is implemented by the dedicated hardware 108. All the functions of the control device 10 may be implemented by the dedicated hardware 108. As the dedicated hardware 108, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof may be used. In addition, the modification example of the hardware resources of the control device 10 described above may also be applied to the control device 10 of other embodiments described later.
[0065] Implementation Method 2
[0066] 2-1. Features of the elevator in Embodiment 2
[0067] In the elevator of the first embodiment, the torque constant is identified when the car load is 0. In contrast, the elevator of the second embodiment is characterized in that the torque constant is identified under any car load condition. The following is an overview of the identification process performed by the parameter identification unit 14 in the first embodiment.
[0068] When the mass of the car 3 when no load acts on the car 3 is set to M1, the car load acting on the car 3 is set to M0, the mass of the counterweight 4 is set to M2, the gravitational acceleration is set to g, and the radius of the sheave of the traction machine 1 is set to the sheave diameter r, the unbalanced torque T1 can be expressed by the following formula.
[0069] T1=(M1+M0-M2)×g×r...(6)
[0070] Based on equation (6) and equation (2), the unbalanced torque T1 can be expressed by the following equation (7).
[0071] T1=(M0-γ×CP)×g×r...(7)
[0072] As shown in equation (7), if the balance ratio γ, rated capacity CP, and sheave diameter r of the hoisting machine 1 are known, the unbalanced torque T1 can be calculated as a known value by measuring the car load M0 of the car 3 using the weighing device 7 .
[0073] Figure 6 This is a diagram showing an example of time variation of the q-axis current value of the hoisting machine 1 when the stationary holding control is executed in the elevator of Embodiment 2 according to different car loads. In this figure, car loads 0%, 30%, and 80% represent the ratio of the car load to the rated capacity CP of the car 3.
[0074] In the example shown in the figure, when the brake device 6 is released from a state where the traction machine 1 is braked to zero rotation speed by the brake device 6, the traction machine 1 rotates due to the unbalanced torque T1 when the weight of the car 3 and the counterweight 4 is unbalanced. The traction machine control unit 12 performs stationary holding control to generate a q-axis current Iq for causing the traction machine 1 to generate a torque T2 to zero rotation speed. Then, when the rotation speed becomes zero, the q-axis current Iq becomes a fixed value, and the q-axis current Iq at this time becomes a stationary holding current that balances the torque T2 and the unbalanced torque T1. As shown in FIG. Figure 6 As shown, the static holding current takes different values depending on the size of the car load. Therefore, if the static holding current is detected using the current sensor 8, the torque constant Kt can be identified using equation (5).
[0075] The parameter identification unit 14 substitutes the car load M0 measured by the weighing device 7 into the formula (7) to calculate the unbalanced torque T1. Then, the parameter identification unit 14 substitutes the calculated unbalanced torque T1 and the static holding current detected by the current sensor 8 into the formula (5) to identify the torque constant Kt. The identified torque constant Kt is sent to the traction machine control unit 12.
[0076] The hoisting machine control unit 12 uses the identified torque constant Kt to set the control gain, particularly the speed control gain, of the hoisting machine control unit 12. Thus, even when the characteristics of the hoisting machine 1 change due to temperature changes or aging, the control performance can be kept constant.
[0077] 2-2. Specific Processing Executed in the Control Device of Embodiment 2
[0078] Figure 7 This is a flowchart showing a routine for the elevator control device according to the second embodiment to identify a torque constant. Figure 7 The routine shown is executed when the rotation speed of the hoisting machine 1 is kept at 0 by the braking device 6 in a state where the car load is acting.
[0079] In steps S200 to S206, the control device 10 performs the same processing as steps S100 to S106. When the processing of step S206 is completed, the processing proceeds to step S208.
[0080] In step S208, the unbalanced torque T1 is calculated. Here, the control device 10 calculates the unbalanced torque T1 by substituting the car load M0 measured by the weighing device 7, the known balance ratio γ, the rated capacity CP, and the sheave diameter r of the traction machine 1 into equation (7). When the processing of step S208 is completed, the processing proceeds to step S210.
[0081] In step S210 , the torque constant Kt is identified. Here, the torque constant Kt is calculated by substituting the stationary holding current value obtained in step S206 and the unbalanced torque T1 calculated in step S208 into equation (5).
[0082] As can be seen from the above description, according to the elevator 100 of Embodiment 2, even in a state where the car load M0 acts, the static holding current detected during the execution of the static holding control can be used to identify the torque constant Kt, which is a characteristic parameter of the motor of the traction machine 1. As a result, the control parameters of the traction machine control unit 12 can be optimized, so that the control performance can be kept constant.
[0083] Implementation 3
[0084] 3-1. Features of the elevator control device in Embodiment 3
[0085] The control device for an elevator according to the third embodiment is characterized by control for identifying the torque constant Kt during the travel of the elevator.
[0086] During the travel of the elevator, the torque components generated by the traction machine 1 include: the torque for compensating for the unbalanced torque T1 of formula (7), the torque generated according to the acceleration and deceleration, the torque for compensating for the travel loss in the elevator shaft, and the torque generated by the weight difference between the car 3 side and the counterweight 4 side of the main rope 5 connecting the car 3 and the counterweight 4, etc.
[0087] Here, when the elevator is running at a constant speed, the torque generated by the acceleration and deceleration can be regarded as 0. In addition, when the car 3 is located in the middle position of the elevator's lifting stroke, the weight of the car 3 side of the main rope 5 and the weight of the counterweight 4 side become equal, so the torque generated by the weight difference on both sides of the main rope 5 can be regarded as 0. That is, when running at a constant speed in the middle position of the lifting stroke, the torque TUP during the ascending operation and the torque TDN during the descending operation of the traction machine 1 can be respectively considered as the sum of the torque compensating for the unbalanced torque T1 and the torque compensating for the running loss. In addition, it can be considered that the running loss during the ascending operation and the running loss during the descending operation are the same in magnitude but different in sign. Therefore, the torque TUP during the ascending operation and the torque TDN during the descending operation of the traction machine 1 are expressed by the following equations (8) and (9).
[0088] TUP=Kt×I1=Kt×(I0+IL1)...(8)
[0089] TDN=Kt×I2=Kt×(I0-IL2)=Kt×(I0-IL1)...(9)
[0090] In formula (8) and formula (9), the first current value I1 is the q-axis current value when the vehicle is traveling at a constant speed in the middle of the lifting stroke during the ascending operation, and the second current value I2 is the q-axis current value when the vehicle is traveling at a constant speed in the middle of the lifting stroke during the descending operation. In addition, IL1 is a current value used to compensate for driving losses during the ascending operation, and IL2 is a current value used to compensate for driving losses during the descending operation. Moreover, I0 is a current value used to compensate for the unbalanced torque T1. According to formula (8) and formula (9), the relationship between the current value I0, the first current value I1, and the second current value I2 is as shown in the following formula (10).
[0091] (I1+I2) / 2=I0...(10)
[0092] As shown in formula (10), the current sensor 8 detects the first current value I1 when the vehicle is traveling at a constant speed in the middle of the lifting stroke in the ascending operation and the second current value I2 when the vehicle is traveling at a constant speed in the middle of the lifting stroke in the descending operation, and takes their average value, so that the current value I0 for compensating the unbalanced torque can be obtained. Therefore, the torque constant Kt can be calculated by the following formula (11).
[0093] Kt=T1 / I0=T1 / ((I1+I2) / 2)...(11)
[0094] 3-2. Specific Example of Identification Processing in Implementation Example 3
[0095] Figure 8 1 is a diagram showing an example of the time variation of the q-axis current value of the hoisting machine 1 and the position of the car in the hoistway when the elevator of Embodiment 3 continuously performs the ascending operation from the lowest floor to the highest floor and the descending operation from the highest floor to the lowest floor. Figure 8 In the figure, the car position is based on the lowest floor. In addition, the reference position in the figure represents the middle position of the lifting stroke, that is, the middle position between the lowest floor and the uppermost floor in the hoistway.
[0096] exist Figure 8In the example shown, in the ascending operation of the elevator 100, after starting to travel at time t1, acceleration in the ascending direction begins. At time t2 when the rated speed is reached, acceleration ends, and the elevator travels at a constant speed with a constant torque. Thereafter, deceleration for stopping at the uppermost floor begins at time t4. In this way, in the ascending operation of the elevator 100, the torque during the constant speed travel is constant, and the torque generated by the acceleration and deceleration during this period can be regarded as 0. In addition, at time t3 when the elevator passes the reference position, the torque generated by the weight difference between the car 3 side and the counterweight 4 side of the main rope 5 can be regarded as 0. As described above, in the ascending operation of the elevator 100, the first current value I1 of the hoisting machine 1 at time t3 when the elevator passes the middle position of the lifting stroke at a constant speed becomes a value obtained by adding the current value I0 for compensating the unbalanced torque T1 to the current value IL1 for canceling the running loss, that is, I1=I0+IL1.
[0097] On the other hand, in the descending operation of the elevator 100, similarly to the ascending operation, after starting to travel at time t5, the elevator accelerates in the descending direction to the rated speed. When the elevator reaches the rated speed at time t6, the acceleration ends and the elevator travels at a constant speed with a constant torque. Then, the elevator starts to decelerate at time t8 for stopping at the lowest floor. In this way, in the descending operation of the elevator 100, the torque during the constant speed travel is constant, and the torque generated by the acceleration and deceleration during this period can be regarded as 0. In addition, at time t7 when the elevator passes the reference position, the torque generated by the weight difference between the car 3 side and the counterweight 4 side of the main rope 5 can be regarded as 0. As described above, in the descending operation of the elevator 100, the second current value I2 of the hoisting machine 1 at time t7 when the elevator passes the middle position of the lifting stroke at a constant speed becomes a value obtained by subtracting the current value IL2 for offsetting the running loss from the current value I0 for compensating the unbalanced torque T1, that is, I2=I0-IL2.
[0098] The first current value I1 and the second current value I2 can be detected by the current sensor 8 during the travel of the elevator 100. Therefore, by substituting the detected first current value I1 and the second current value I2 and the unbalanced torque T1 into the equation (11), the torque constant Kt can be identified.
[0099] 3-3. Specific Processing Executed by the Control Device in Embodiment 3
[0100] Fig. 9 This is a flowchart showing a routine for identifying a torque constant by the elevator control device according to Embodiment 3. The control device 10 executes this routine when a car load M0 acts.
[0101] In step S300, the elevator 100 is operated to ascend from the lowest floor to the highest floor. In step S302, the first current value I1 is obtained when the elevator passes through the reference position at a constant speed. The reference position here is a position where the weight of the main rope 5 on the car 3 side is balanced with the weight of the main rope 5 on the counterweight 4 side. After that, the elevator 100 stops at the highest floor.
[0102] In step S304, the vehicle is lowered from the uppermost floor to the lowermost floor. In step S306, a second current value I2 is obtained when the vehicle passes through the reference position at a constant speed.
[0103] In step S308, the torque constant Kt is identified. Here, the unbalanced torque T1 is calculated. The control device 10 calculates the unbalanced torque T1 by substituting the car load M0 measured by the weighing device 7, the known balance rate γ, the rated capacity CP and the sheave diameter r of the traction machine 1 into equation (7). Then, the torque constant Kt is calculated by substituting the calculated unbalanced torque T1 and the first current value I1 and the second current value I2 obtained in steps S302 and S306 into equation (11).
[0104] As can be seen from the above description, according to the elevator control device of Embodiment 3, even during the travel of the elevator 100, the torque constant Kt, which is the motor characteristic parameter of the traction machine 1, can be identified using the current value when the elevator passes the reference position at a constant speed. As a result, the control parameters of the traction machine control unit 12 can be optimized, and thus the control performance can be kept constant.
[0105] 3-4. Modifications
[0106] The elevator control device 10 according to the third embodiment may also adopt the following modified forms.
[0107] In the identification process, the elevator 100 may first perform a descending operation to obtain the second current value I2, and then perform an ascending operation to obtain the first current value I1. Fig. 9 In the illustrated flowchart, the processes of steps S304 and S306 may be executed before the process of step S300.
[0108] The ascending operation of the elevator 100 in step S300 does not necessarily need to be operated from the lowest floor to the highest floor. That is, the ascending operation here only needs to be able to at least pass the reference position at a constant speed. In addition, the descending operation of the elevator 100 in step S304 is also the same, and does not necessarily need to be operated from the highest floor to the lowest floor. That is, the descending operation here only needs to be able to at least pass the reference position at a constant speed.
[0109] The control device 10 can also be executed when the car load M0 is not applied. Fig. 9In this case, in step S308, the unbalanced torque can be calculated using equation (3).
[0110] Implementation 4
[0111] 4-1. Features of the elevator control device in Embodiment 4
[0112] The elevator control device of the fourth embodiment is characterized by identifying a current control band as a characteristic parameter of the hoisting machine 1 and adjusting a current control parameter using the identified current control band. The current control parameter here is, for example, a current control gain.
[0113] The car load M0 acting on the car 3 can be measured using the weighing device 7. Therefore, if the unbalanced torque T1 calculated by substituting the car load M0 into the formula (6) and the torque constant Kt into the formula (4), the compensation current value for compensating the unbalanced torque T1 can be calculated. Then, if the brake device 6 is released after the calculated compensation current value is passed in advance, it is possible to quickly perform a stationary holding control that makes the rotation speed close to 0 immediately after the brake device 6 is released. Before the elevator 100 travels and when the traction machine 1 is braked by the brake device 6, the current response when the instruction of the compensation current value for compensating the unbalanced torque T1 is applied in a step-like manner is used to perform an identification process for identifying the current control band. The identification process for identifying the current control band is described in detail below.
[0114] When the hoisting machine 1 stops, the relationship between the current I and the voltage V of the motor of the hoisting machine 1 can be expressed by the following equation (12). Here, the current I is the dq axis current of the motor, and the voltage V is the dq axis voltage of the motor. In addition, L is the inductance of the motor, R is the resistance of the motor, and s is the Laplace operator.
[0115] I=1 / (Ls+R)×V...(12)
[0116] In contrast, the current control of the hoisting machine control unit 12 is generally designed as shown in the following equation (13): wherein ω is the current control band, and I* is the current command value. In addition, the proportional gain is represented by ω×L, and the integral gain is represented by ω×R.
[0117] V=ω / s×(Ls+R)×(I*-I)...(13)
[0118] If equation (13) is applied to equation (12) to derive a closed-loop response, the current I is represented by the following first-order delay system.
[0119] I=ω / (s+ω)×I*=1 / (Ts+1)×I*...(14)
[0120] Here, T is a time constant, T=1 / ω. If the current command value I* is given in a step-like manner, its time response is expressed by the following equation.
[0121] I=(1-EXP(-t / T))×I*...(15)
[0122] When the time t from the application of the current command value I* becomes t=T, the current I becomes 63% of the current command value I*. That is, by measuring the time when the actual current I becomes 63% of the current command value I*, detecting the deviation from the ideal time constant T, or the deviation between the inverse of the measured time and the current control band ω, the error of the current control gain can be detected. In this way, the gain of the current control can be adjusted. In particular, the time constant is proportional to the proportional gain, that is, the inductance, so the error of the inductance can be detected. In addition, according to formula (15), the ideal value of the current I can also be known at times other than t=T, so by comparing the current value at any time with the ideal response, the current control gain can also be adjusted.
[0123] 4-2. Specific Example of Current Control Parameter Adjustment Processing in Embodiment 4
[0124] Fig.10 This is a diagram showing an example of the time variation of the q-axis current value and the rotation speed of the hoisting machine 1 when the stationary holding control is performed in the elevator of the fourth embodiment. In the example shown in the figure, the instruction of the compensating current for compensating the unbalanced torque T1 is provided in a step-like manner before the brake device 6 is released. As a result, the actual current follows the instruction value according to the formula (15). At this time, by measuring the time Tx when the actual current reaches 63% of the instruction value, the deviation of the current control gain can be detected. For example, when the time Tx is Tx>T, it can be judged that the proportional gain is insufficient because the actual current rises slowly. This means that the current control band is insufficient compared to the design, and the inductance used to design the proportional gain is smaller than the actual one. Therefore, in such a case, by increasing the inductance used in the design of the proportional gain, the actual current can be made close to the ideal response.
[0125] On the other hand, when the elapsed time Tx is Tx<T, the actual current rises earlier, so it can be determined that the proportional gain is excessive. This means that the current control band is excessive compared to the design, and the inductance used to design the proportional gain is larger than the actual value. Therefore, in such a case, by reducing the inductance used in the design of the proportional gain, the actual current can be made closer to the ideal response.
[0126] 4-3. Specific Processing Executed by the Control Device in Embodiment 4
[0127] Fig.11This is a flowchart showing a routine for adjusting current control parameters by the elevator control device according to the fourth embodiment. Fig.11 The routine shown is executed when the car 3 is stopped with the rotation speed of the hoisting machine 1 being maintained at 0 by the braking device 6 .
[0128] In step S400, the hoisting machine control unit 12 instructs a compensation current value for compensating for the unbalanced torque T1 in a step-like manner while the hoisting machine 1 is braked by the brake device 6. In step S402, the parameter identification unit 14 measures the elapsed time Tx from the hoisting machine control unit 12 instructing the compensation current.
[0129] In the next step S404, the parameter identification unit 14 determines whether the actual current supplied to the hoisting machine 1 reaches a predetermined ratio to the compensation current value. Here, it is determined whether the actual current detected by the current sensor 8 reaches 63% of the predetermined ratio as the command value. As a result, if it is not confirmed that the determination is established, the process returns to step S402 again, and the measurement of the elapsed time Tx is continued.
[0130] On the other hand, when it is confirmed that the judgment is established, the processing enters step S406. In step S406, the parameter identification unit 14 stops measuring the elapsed time Tx. After executing the processing of step S406, the processing enters step S408. In step S408, the parameter identification unit 14 identifies the measured elapsed time Tx as the time constant T, and identifies the reciprocal of the time constant T as the current control band ω. Then, using the identified time constant T or current control band ω, the control gain of the traction machine control unit 12 is set. The control gain here is the current control gain, specifically the proportional gain. In addition, the proportional gain is proportional to the inductance of the motor, so it is also an identified inductance.
[0131] As can be seen from the above description, according to the control device of the elevator of the fourth embodiment, in the stationary holding control, the current control band can be identified based on the response of the actual current when the compensation current value for compensating the unbalanced torque is passed before the brake device 6 is released. Thus, the current control gain can be adjusted using the identified current control band, so that the control performance can be kept constant. In addition, the current control band is proportional to the inductance of the motor, so the inductance can also be identified. In addition, the time constant is the inverse of the current control band, so the time constant can also be identified.
[0132] 4-4. Modification
[0133] The elevator control device of the fourth embodiment may also be modified as follows.
[0134] exist Fig.11 In step S404 of the routine shown, the predetermined ratio is not limited to 63% and may be any ratio.
Claims
1. A control device for an elevator, the elevator comprising: a car; a main rope, one end of which is connected to the car and the other end of which is connected to a counterweight; and a traction machine, which hangs the main rope around a sheave to raise and lower the car, wherein: The elevator control device comprises: a traction machine control unit that controls the traction machine using control parameters; and a parameter identification unit for identifying characteristic parameters of the traction machine, The parameter identification unit is configured to identify the characteristic parameter using a current value flowing through the hoisting machine and an unbalanced torque generated by a weight difference between the car and the counterweight, The hoisting machine control unit is configured to set the control parameter based on the characteristic parameter.
2. The elevator control device according to claim 1, wherein: The hoisting machine control unit is configured to release the braking device of the hoisting machine when the car load of the car is zero and perform stationary holding control to make the car stationary, The parameter identification unit is configured to calculate the unbalanced torque using the current value of the traction machine during the stationary holding control, the rated capacity of the car, the balance rate of the counterweight and the sheave diameter of the traction machine, and use the unbalanced torque to identify the torque constant of the traction machine as the characteristic parameter.
3. The elevator control device according to claim 1, wherein: The elevator control device includes a weighing device for detecting a car load of the car. The hoisting machine control unit is configured to release a brake device of the hoisting machine and perform stationary holding control to stationary the car. The parameter identification unit is configured to calculate the unbalanced torque using the current value of the hoisting machine during the stationary holding control, the rated capacity of the car, the balance rate of the counterweight, the sheave diameter of the hoisting machine and the car load, and use the unbalanced torque to identify the torque constant of the hoisting machine as the characteristic parameter.
4. The control device of an elevator according to claim 1, wherein: The hoisting machine control unit is configured to execute the ascending operation and the descending operation of the elevator. The parameter identification unit respectively obtains a first current value of the hoisting machine when the car passes a reference position of the shaft at a constant speed in the ascending operation of the elevator, and a second current value of the hoisting machine when the car passes the reference position at a constant speed in the descending operation of the elevator, and uses the first current value, the second current value and the unbalanced torque to identify the torque constant of the hoisting machine as the characteristic parameter.
5. The control device of an elevator according to claim 4, wherein: The reference position is an intermediate position in the lifting stroke of the elevator.
6. The control device of an elevator according to claim 1, wherein: The hoisting machine control unit provides a command value in a step-like manner before releasing the brake device of the hoisting machine, wherein the command value is used to pass a compensation current value for compensating the unbalanced torque to the hoisting machine, The parameter identification unit measures an elapsed time until the current value of the hoisting machine reaches a predetermined ratio of the compensation current value, and identifies a current control band of the hoisting machine control unit as the characteristic parameter based on the elapsed time.
7. The control device of an elevator according to claim 6, wherein: The parameter identification unit is configured to identify the inductance of the hoisting machine as the characteristic parameter based on the current control band.