Elevator control device

Abstract

Identify the inertia and torque constants of the elevator without requiring special operating conditions of the elevator, and optimize the control gain used for the control of the hoist. 【Solution means】 The elevator control device includes a speed control unit that calculates a current command value of the current flowing through the hoist so that the speed of the car running in the hoistway becomes the speed command value, a current control unit that controls the hoist so that the actual current value flowing through the hoist becomes the current command value, a torque constant identification unit that identifies the torque constant of the hoist using the current value including the actual current value or the current command value and the car load acting on the car, an inertia identification unit that identifies the inertia of the elevator using the current value, the acceleration or deceleration of the car, and the torque constant, and a gain update unit that updates the gain used in the calculation of the speed control unit using the inertia and the torque constant.

Description

Technical Field

[0001] The present disclosure relates to the technology of an elevator control device.

Background Art

[0002] Patent Document 1 discloses a technology related to a servo device that controls the position and speed of a mechanical system including a servo motor. The servo device of this technology estimates the inertia term, viscous term, Coulomb friction, steady-state disturbance force, and torque constant of the mechanical system, and changes the parameters of the control system based on the numerical values of the estimated parameters.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Estimated parameters such as inertia and torque constant are related to each other. Therefore, in the technology described in Patent Document 1, when considering accurately estimating each parameter, different operating conditions are required for identifying each parameter, and there is a problem that the identification burden of the parameters increases.

[0005] The present disclosure has been made to solve the above-described problems, and an object thereof is to provide a technology for identifying the inertia and torque constant of an elevator and optimizing the control gain used for controlling a hoist without requiring special operating conditions of the elevator.

Means for Solving the Problems

[0006] The elevator control device of the present disclosure includes a speed control unit that calculates a current command value of the current flowing through the hoist so that the speed of the car traveling in the elevator hoistway becomes the speed command value, a current control unit that controls the hoist so that the actual current value flowing through the hoist becomes the current command value, a torque constant identification unit that identifies the torque constant of the hoist using the current value including the actual current value or the current command value and the car load acting on the car, an inertia identification unit that identifies the inertia of the elevator using the current value, the acceleration or deceleration of the car, and the torque constant, and a gain update unit that updates the gain used in the calculation of the speed control unit using the inertia and the torque constant. In such an elevator control device, the torque constant identification unit is configured to identify the torque constant using the current value when the car passes the reference position of the hoistway at a constant speed during the upward operation of the elevator, the current value when the car passes the reference position at a constant speed during the downward operation of the elevator, and the car load. Alternatively, the inertia identification unit acquires a first current value and a first acceleration, which are the current value and the acceleration when the car is accelerating in the upward direction at a first position in the hoistway, acquires a second current value and a second deceleration, which are the current value and the deceleration when the car is decelerating in the upward direction at a second position in the hoistway, calculates a first inertia identification value using the first current value, the first acceleration, the second current value, the second deceleration, and the torque constant, acquires a third current value and a third acceleration, which are the current value and the acceleration when the car is accelerating in the downward direction at a third position in the hoistway, acquires a fourth current value and a fourth deceleration, which are the current value and the deceleration when the car is decelerating in the downward direction at a fourth position in the hoistway, calculates a second inertia identification value using the third current value, the third acceleration, the fourth current value, the fourth deceleration, and the torque constant, and is configured to identify the inertia based on the first inertia identification value and the second inertia identification value. Alternatively, the inertia identification unit is configured to identify the inertia for each of a plurality of different car loads, and the gain update unit is configured to calculate the inertia for each car load by linearly interpolating the identified inertias and update the gain for each car load. Alternatively, the inertia identification unit is configured to identify the inertia when the car load is zero, and the gain update unit is configured to update the gain corresponding to the car load using the inertia obtained by adding an inertia correction value corresponding to the car load to the inertia identified when the car load is zero.

Advantages of the Invention

[0007] According to the technology of the present disclosure, it is possible to identify the inertia and torque constant of an elevator without requiring special operating conditions of the elevator and optimize the control gain used for the control of the hoist.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described with reference to the drawings. In the drawings, common elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[0010] Embodiment 1. 1-1. Configuration of the Elevator in Embodiment 1 FIG. 1 is a configuration diagram of the elevator of Embodiment 1. The elevator 100 of Embodiment 1 is installed in a facility such as a building having a plurality of floors. In the facility, a hoistway for the elevator 100 is provided. The hoistway is a vertically long space extending over a plurality of floors.

[0011] The elevator 100 mainly includes a hoisting machine 1, a rotation sensor 4, a main rope 5, a car 6, a counterweight 7, a weighing device 8, a current sensor 9, and a control device 10.

[0012] The hoisting machine 1 is installed, for example, at the upper part of the hoistway. The hoisting machine 1 includes an electric motor 3 and a sheave 2 attached to the shaft of the electric motor 3. The electric motor 3 is a power source for moving the car 6 up and down, and a permanent magnet synchronous motor or an induction motor is used.

[0013] The rotation sensor 4 is installed on the electric motor 3 and detects the rotation angle θ of the electric motor 3. Examples of the rotation sensor 4 include an optical encoder or a resolver. The rotation angle θ of the electric motor 3 detected by the rotation sensor 4 is input to the control device 10 and used for speed control and current control of the electric motor 3.

[0014] The main rope 5 is wound around the hoisting drum 2 of the hoisting machine 1. A cage 6 is connected to one end of the main rope 5. A counterweight 7 is connected to the other end of the main rope 5. The cage 6 and the counterweight 7 are suspended in a pendulum-like manner in the hoistway by the main rope 5. The cage 6 and the counterweight 7 move up and down in the hoistway by rotating the hoisting drum 2 of the hoisting machine 1.

[0015] Note that the weight of the counterweight 7 is adjusted based on the weight ratio of the cage 6 to the rated capacity CP of the cage 6, which is called the "counter rate γ". For example, when the counter rate γ is set to 50%, the weight of the counterweight 7 is adjusted to a value obtained by adding the mass of the cage 6 to the weight of 50% of the rated capacity CP.

[0016] The weighing device 8 detects the load acting on the cage 6. The weighing device 8 may be attached to the cage 6 or may be attached to the terminal of the main rope 5. The weighing device 8 is not limited by the installation position and form as long as it can detect the load acting on the cage 6. Also, in FIG. 1, an elevator with a 1:1 roping is illustrated, but a 2:1 roping or other roping may be used.

[0017] The current sensor 9 detects the current flowing through the electric motor 3. Note that the current value detected by the current sensor 9 is the UVW phase current of the electric motor 3.

[0018] The control device 10 includes a speed detection unit 12, a speed control unit 14, a current control unit 16, a torque constant identification unit 18, an inertia identification unit 20, and a gain update unit 22 as functions realized by a processor executing a program.

[0019] The speed detection unit 12 is a functional block for calculating the rotational speed ω of the electric motor 3 from the rotational angle θ of the electric motor 3 detected by the rotation sensor 4. The rotational speed ω calculated by the speed detection unit 12 is sent to the speed control unit 14.

[0020] The speed control unit 14 is a functional block for controlling the rotational speed of the electric motor 3 to determine the current command value I*. Typically, the speed control unit 14 is configured by, for example, PID control. The speed control unit 14 calculates the current command value I* such that the speed command value ω* matches the rotational speed ω calculated by the speed detection unit 12. The control gain of the speed control unit 14, for example, the PID control gain, is updated by the gain update unit 22 described later.

[0021] The current control unit 16 is a functional block for calculating the voltage command value V* to be applied to the electric motor 3. Typically, the current control unit 16 is configured by, for example, PID control. The current control unit 16 calculates the voltage command value V* such that the actual current value I detected by the current sensor 9 follows the current command value I* calculated by the speed control unit 14.

[0022] Note that in the current control of the electric motor 3, a dq-axis coordinate system is generally used. At this time, the current command value I* which is the output of the speed control unit 14 is the command value of the q-axis current, and the voltage command value V* which is the output of the current control unit 16 is the command value of the q-axis voltage. On the other hand, since the d-axis is not relevant to the present disclosure, it is omitted in FIG. 1. When the electric motor 3 is a permanent magnet synchronous motor, the command value of the d-axis current is set to 0, but there are cases where the command value of the d-axis current is not set to 0 due to field weakening control or the like. When the electric motor 3 is an induction motor, a constant d-axis current is commanded as the excitation current. The d-axis voltage according to these d-axis current command values is also converted into the phase voltage of the electric motor 3 together with the q-axis voltage and applied to the electric motor 3. Also, the current value detected by the current sensor 9 is the UVW phase current of the electric motor 3, and this is coordinate-transformed into dq-axis currents using the rotational phase of the electric motor 3 detected by the rotational sensor 4 and used for the current control of the current control unit 16.

[0023] The torque constant identification unit 18 is a functional block for identifying the torque constant Kt of the motor 3. Typically, the torque constant identification unit 18 identifies the torque constant Kt using the current command value I* calculated by the speed control unit 14, the rotation angle θ of the motor 3 detected by the rotation sensor 4, and the car load W of the car 6 detected by the weighing device 8. This process is hereinafter referred to as the "torque constant identification process". Here, the torque constant is a proportional constant indicating the relationship between the q-axis current value I and the torque T of the motor 3, and there is the relationship of the following formula (1). The relational expression between the torque command value T* and the current command value I* is the following formula (2) in which the q-axis current value I in formula (1) is replaced with the current command value I*. Details of the torque constant identification process will be described later.

[0024] T = Kt × I ···(1) T* = Kt × I* ···(2)

[0025] The inertia identification unit 20 is a functional block for identifying the inertia J of the elevator. The inertia J here indicates the total inertia of the system as seen from the motor 3. That is, the inertia J is the inertia that the motor 3 should control. The inertia identification unit 20 identifies the inertia J using the torque constant Kt identified by the torque constant identification unit 18, the current command value I* calculated by the speed control unit 14, and the rotation angle θ of the motor 3 detected by the rotation sensor 4. This process is hereinafter referred to as the "inertia identification process". Details of the inertia identification process will be described later.

[0026] The gain update unit 22 is a functional block for updating the gain of the speed control unit 14. Typically, the gain update unit 22 calculates and updates the gain of the speed control unit 14 using the torque constant Kt identified by the torque constant identification unit 18, the inertia J identified by the inertia identification unit 20, and the car load W of the car 6 detected by the weighing device 8. This process is hereinafter referred to as the "gain update process". Details of the gain update process will be described later.

[0027] 1-2. Outline of Torque Constant Identification Process Next, the outline of the torque constant identification process performed in the torque constant identification unit 18 will be described. In the following description, the range from the middle position in the vertical direction of the hoistway to the top floor is referred to as the "upper region", and the range from the middle position to the bottom floor is referred to as the "lower region". In the upward operation of the elevator, the torque Tua acting on the motor 3 during acceleration in the lower region is expressed by the following equation (3).

[0028] Tua = Ju × aua + Uc - Ur - L ···(3)

[0029] In equation (3), Ju represents the inertia of the elevator during upward operation, aua represents the acceleration of the elevator during upward operation, Uc represents the torque acting on the motor 3 due to the weight difference between the car 6 and the counterweight 7, Ur represents the torque acting on the motor 3 due to the rope weight difference between the weight of the main rope 5 between the car 6 and the sheave 2 and the weight of the main rope 5 between the counterweight 7 and the sheave 2, and L represents the torque of the running loss of the elevator. The inertia Ju is also hereinafter referred to as the "first inertia identification value". Note that the sign of Uc changes depending on the load of the car 6. For example, when the counterweight ratio is 50%, if the load of the car 6 exceeds 50% of the rated capacity, the weight of the car 6 becomes larger than the weight of the counterweight 7, so the sign changes. Also, the sign of Ur changes depending on the position of the car 6. For example, when the car 6 is located in the lower region, the main rope 5 on the car 6 side is longer than the main rope 5 on the counterweight 7 side, but when the car 6 is located in the upper region, the main rope 5 on the counterweight 7 side becomes longer than the main rope 5 on the car 6 side. Therefore, when the car 6 crosses the middle position of the hoistway and moves from the lower region to the upper region, the sign of Ur changes.

[0030] During upward operation, when the elevator travels at a constant speed and is not accelerating or decelerating, the torque Tum acting on the motor 3 is expressed by the following equation (4) obtained by ignoring the acceleration term from equation (3).

[0031] Tum = Uc - Ur - L ···(4)

[0032] In the upward operation of the elevator, the torque Tud acting on the motor 3 during deceleration in the upper region is expressed by the following equation (5).

[0033] Tud = Ju × aud + Uc + Ur - L ···(5)

[0034] In equation (5), aud represents the deceleration during upward operation. In equation (5), the sign of the torque Ur due to the rope weight difference has changed compared to equation (3). This is because the car 6 is moving from the lower region to the upper region across the middle position of the hoistway.

[0035] Next, in the downward operation of the elevator, the torque Tda acting on the motor 3 during acceleration in the upper region is expressed by the following equation (6).

[0036] Tda = Jd × ada + Uc + Ur + L ···(6)

[0037] In equation (6), Jd represents the inertia of the elevator during downward operation, and ada represents the acceleration of the elevator during downward operation. The inertia Jd is also referred to as the "second inertia identification value" below.

[0038] During the downward operation of the elevator, when the elevator is running at a constant speed and not accelerating or decelerating, the torque Tdm acting on the motor 3 is expressed by the following equation (7) obtained by ignoring the acceleration term in equation (6).

[0039] Tdm = Uc + Ur + L ···(7)

[0040] In the downward operation of the elevator, the torque Tdd acting on the motor 3 during deceleration in the lower region is expressed by the following equation (8). In equation (8), add represents the deceleration of the elevator during downward operation.

[0041] Tdd = Jd × add + Uc - Ur + L ···(8)

[0042] Here, when the car 6 is positioned at the intermediate position as the reference position of the elevating / lowering stroke of the elevator, since the weight of the main rope 5 on the car 6 side and the weight of the main rope 5 on the counterweight 7 side are equal, the torque Ur generated by the weight difference of the main rope 5 can be regarded as zero. Also, it can be considered that the torque L of the running loss during the upward operation is the same magnitude as the torque L of the running loss during the downward operation. Therefore, when obtaining the sum of Equation (4) and Equation (7), the torque L due to the running loss is canceled out and the following Equation (9) is obtained.

[0043] Tum + Tdm = 2Uc ···(9)

[0044] Since the relationship between the torque T and the current value I is expressed as T = Kt×I, the torque Tum when traveling at the intermediate position of the elevating / lowering stroke during the upward operation and the torque Tdm when traveling at the intermediate position of the elevating / lowering stroke during the downward operation are expressed by the following Equations (9) and (10).

[0045] Tum = Kt×Ium ···(9) Tdm = Kt×Idm ···(10)

[0046] The current values Ium and Idm here can use the current command value I* calculated by the speed control unit 14 when traveling at a constant speed at the intermediate position of the elevating / lowering stroke during the upward operation and the downward operation. Alternatively, the current values Ium and Idm may be the current values I detected by the current sensor 9 when traveling at a constant speed at the intermediate position of the elevating / lowering stroke during the upward operation and the downward operation. The position of the car 6 in the hoistway can be detected using, for example, the rotation angle θ detected by the rotation sensor 4 of the electric motor 3. Note that the detection means for the position of the car 6 in the hoistway is not limited to the above, and any configuration may be used as long as it can detect the position of the car 6 in the hoistway. From Equations (9) and (10), the torque constant Kt can be obtained by the following Equation (11).

[0047] Kt = 2Uc / (Ium + Idm) ···(11)

[0048] When no load is acting on the car 6, the torque Uc due to the weight difference between the car 6 and the counterweight 7 can be calculated by the following equation (12) using the rated capacity CP of the car 6, the counter rate γ, the radius r of the sheave 2, and the gravitational acceleration g. When a load W is acting on the car 6, the torque Uc can be calculated by the following equation (13) using the car load W detected by the weighing device 8.

[0049] Uc = CP × γ × g × r ···(12) Uc = (CP × γ + W) × g × r ···(13)

[0050] As described above, the torque constant identification unit 18 can identify the torque constant Kt by substituting the torque Uc calculated using equation (12) or (13) and the current values Ium and Idm obtained when traveling at a constant speed at the intermediate position of the lifting and lowering stroke in the upward and downward operations into equation (11).

[0051] 1-3. Outline of Inertia Identification Process Next, the outline of the inertia identification process performed in the inertia identification unit 20 will be described. Let Ur1 be the torque Ur due to the rope weight difference at the first position P1 in the lower region and Ur2 be the torque Ur due to the rope weight difference at the second position P2 in the upper region. Then, in the upward operation of the elevator, the torque Tua during acceleration at the first position P1 of the lifting and lowering stroke and the torque Tud during deceleration at the second position P2 of the lifting and lowering stroke are given by the following equations (14) and (15) from equations (3) and (5). In equations (14) and (15), the acceleration aua is also called the "first acceleration" and the deceleration aud is also called the "second deceleration".

[0052] Tua = Ju × aua + Uc - Ur1 - L ···(14) Tud = Ju × aud + Uc + Ur2 - L ···(15)

[0053] When there is no change in the number of passengers in the car 6 at the first position P1 and the second position P2, the torque Uc due to the weight difference between the car 6 and the counterweight 7 can be considered to have the same value at the first position P1 and the second position P2. Also, assuming that the torque L due to the running loss is the same at the first position P1 and the second position P2, from equations (14) and (15), the first inertia identification value Ju is given by the following equation (16).

[0054] Ju=(Tua - Tud + Ur1 + Ur2) / (aua - aud) ···(16)

[0055] Similarly, if the torque Ur due to the rope weight difference at the third position P3 in the upper region is Ur3 and the torque Ur due to the rope weight difference at the fourth position P4 in the lower region is Ur4, then in the downward operation of the elevator, the torque Tda during acceleration at the third position P3 and the torque Tdd during deceleration at the fourth position P4 are given by the following equations (17) and (18) from equations (6) and (8). In equations (17) and (18), the acceleration ada is also called the "third acceleration" and the deceleration add is also called the "fourth deceleration".

[0056] Tda = Jd×ada + Uc + Ur3 + L ···(17) Tdd = Jd×add + Uc - Ur4 + L ···(18)

[0057] Here, when the first position P1 and the fourth position P4, and the second position P2 and the third position P3 are at the same position, Ur1 and Ur4, and Ur2 and Ur3 have the same value respectively. Therefore, from equations (17) and (18), the second inertia identification value Jd is given by the following equation (19).

[0058] Jd=(Tda - Tdd - Ur1 - Ur2) / (ada - add) ···(19)

[0059] Here, when the elevator is operated so that the first acceleration aua during upward operation, the third acceleration ada during downward operation, the second deceleration aud during upward operation, and the fourth deceleration add during downward operation are the same, the sum of the first inertia identification value Ju and the second inertia identification value Jd is represented by the following equation (20).

[0060] Ju + Jd = ((Tua - Tud) + (Tda - Tdd)) / (aua - aud) ···(20)

[0061] Taking the average value of the first inertia identification value Ju and the second inertia identification value Jd as the final inertia J identification value, and replacing each torque value with a current value in Equation (20), the following equation (21) is obtained. In Equation (21), the current values Iua, Iud, Ida, and Idd are also referred to as the "first current value", "second current value", "third current value", and "fourth current value", respectively.

[0062] J = (Ju + Jd) / 2 = Kt((Iua - Iud) + (Ida - Idd)) / (aua - aud) / 2 ···(21)

[0063] As described above, the inertia identification unit 20 can identify the inertia J by substituting the torque constant Kt identified by the torque constant identification unit 18 and the current values Iua, Iud, Ida, and Idd obtained during specific operation with the above-described accelerations aua and aud into Equation (21).

[0064] 1 - 4. Outline of Gain Update Processing The gain update unit 22 updates the gain used in the speed control unit 14 using the torque constant Kt identified by the torque constant identification unit 18 and the inertia J identified by the inertia identification unit 20. The speed control of the motor 3 by the speed control unit 14 is configured by, for example, PI control. At this time, the P gain KP and the I gain KI are designed as in the following equations (22) and (23).

[0065] KP = ωc × J / Kt ···(22) KI = KP × ωc / 5 ···(23)

[0066] In equations (22) and (23), ωc is the control bandwidth of the speed control unit 14. As in equations (22) and (23), the PI gain of the speed control unit 14 is determined by the inertia J and the torque constant Kt. If the inertia and torque constant set in the speed control unit 14 deviate from the actual values, there may be problems such as the occurrence of control errors and oscillations in the control system. Therefore, stable control can be implemented by optimizing the gain of the speed control unit 14 using the identified torque constant Kt and inertia J. Note that the speed control by the speed control unit 14 is not limited to PI control, and can be configured by various control methods such as PID control or two-degree-of-freedom control, for example. The identified inertia J and torque constant Kt can also be used for gain updates of such other control methods.

[0067] 1-5. Specific processing executed in the control device in Embodiment 1 FIG. 2 is a diagram for explaining the operation of the elevator executed when performing the torque constant identification process and the inertia identification process. FIG. 3 is a flowchart showing the routine of the process executed by the control device of Embodiment 1. Hereinafter, the specific processing executed in the control device will be described with reference to FIG. 2 as well.

[0068] In step S100, the upward operation of the elevator is started. The upward operation includes an acceleration operation, a constant-speed operation, and a deceleration operation. Usually, in order to improve the riding comfort of the elevator, a jerk is provided and it takes several seconds to reach a certain acceleration. In the upward acceleration operation, after the motor 3 reaches a certain first acceleration aua, it continues to accelerate at the first acceleration aua until it reaches the rated speed. When the rated speed is reached, the upward operation shifts to the constant-speed operation. In the constant-speed operation, the motor 3 continues to operate at the rated speed. Then, when approaching the target floor, the upward operation shifts to the deceleration operation. Also in the deceleration operation, a jerk is provided as in the acceleration operation and it takes several seconds to reach a certain deceleration. In the deceleration operation, after the motor 3 reaches a certain second deceleration aud, it continues to decelerate at the second deceleration aud until the speed reaches zero.

[0069] During the period when the upward operation in step S100 is being performed, the processes from step S102 to step S106 are executed in sequence. Typically, in step S102, at the first position P1 during the acceleration operation with a certain first acceleration aua, the first current value Iua is acquired. Here, the current command value I* when the car position calculated from the rotation angle θ of the motor 3 detected by the rotation sensor 4 reaches the first position P1 is acquired as the first current value Iua.

[0070] In step S104, at the reference position during the constant-speed operation, the current value Ium is acquired. The reference position here is the middle position of the elevator's up and down travel. Here, the current command value I* when the car position calculated from the rotation angle θ of the motor 3 reaches the middle position is acquired as the current value Ium.

[0071] In step S106, at the second position P2 during the deceleration operation with a certain second deceleration aud, the second current value Iud is acquired. Here, the current command value I* when the car position calculated from the rotation angle θ of the motor 3 detected by the rotation sensor 4 reaches the second position P2 is acquired as the second current value Iud.

[0072] When the upward operation of the elevator ends, the process proceeds to step S108. In step S108, the downward operation of the elevator is started. The downward operation, similar to the upward operation, includes an acceleration operation, a constant-speed operation, and a deceleration operation. The third acceleration ada when accelerating in the downward direction is equal to the first acceleration aua when accelerating in the upward direction. Also, the fourth deceleration add when decelerating in the downward direction is equal to the second deceleration aud when decelerating in the upward direction. Also, in the acceleration operation and deceleration operation in the downward direction, a jerk is provided to improve the riding comfort of the elevator.

[0073] During the period when the downward operation in step S108 is being performed, the processes from step S110 to step S114 are executed in order. Typically, the process of step S110 is executed at the third position P3 during the acceleration operation with a constant third acceleration ada, and the third current value Ida is obtained. Here, the current command value I* when the car position calculated from the rotation angle θ of the motor 3 reaches the third position P3 is obtained as the third current value Ida. Note that the third position P3 here is the same position as the second position P2.

[0074] The process of step S112 is executed at the reference position during the constant-speed operation, and the current value Idm is obtained. Here, the current command value I* when the car position calculated from the rotation angle θ of the motor 3 reaches the intermediate position which is the reference position is obtained as the current value Idm.

[0075] At the fourth position P4 during the deceleration operation with a constant fourth deceleration add, the process of step S114 is executed, and the fourth current value Idd is obtained. Here, the current command value I* when the car position calculated from the rotation angle θ of the motor 3 detected by the rotation sensor 4 reaches the fourth position P4 is obtained as the fourth current value Idd. Note that the fourth position P4 here is the same position as the first position P1.

[0076] When the process of step S114 is completed, the process proceeds to the torque constant identification process of step S116. Here, the torque constant identification unit 18 identifies the torque constant Kt by substituting the current value Ium acquired in step S104 and the current value Idm acquired in step S112 into Equation (11). Note that the torque Uc is calculated by substituting the basket load W detected by the weighing device 8 into Equation (13).

[0077] When the process of step S116 is completed, the process proceeds to the inertia identification process of step S118. Here, the inertia identification unit 20 identifies the inertia J by substituting the current value Iua acquired in step S102, the current value Iud acquired in step S106, the current value Ida acquired in step S110, the current value Idd acquired in step S114, and the torque constant Kt identified in step S114 into Equation (21).

[0078] When the process of step S118 is completed, the process proceeds to the gain update process of step S120. Here, the gain update unit 22 updates the P gain KP and the I gain KI by substituting the torque constant Kt identified in step S116 and the inertia J identified in step S118 into Equations (22) and (23).

[0079] As is clear from the above description, according to the elevator control device 10 of Embodiment 1, the inertia J and the torque constant Kt of the elevator 100 can be identified by performing the upward operation and the downward operation once each without requiring special operating conditions for the elevator 100. Thereby, the control gain used for the control of the hoist 1 can be optimized, so that the control performance can be kept constant.

[0080] Note that the torque constant and inertia are inherent values of the motor 3 and the elevator and do not change. Therefore, the identification of the torque constant and the identification of the inertia may be performed once when the elevator is installed. Alternatively, it may be performed during maintenance inspection or the like. This also applies to other embodiments described later.

[0081] 1-6. Modification Example The elevator 100 of Embodiment 1 may adopt the following modified form.

[0082] 1-6-1. Hardware Resources of the Control Device 10

[0083] FIG. 4 is a diagram showing an example of the 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.

[0084] In the present embodiment, the speed detection unit 12, the speed control unit 14, the current control unit 16, the torque constant identification unit 18, the inertia identification unit 20, and the gain update unit 22 indicate functions of the control device 10. These functions 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 may be recorded on a computer-readable recording medium. The control device 10 realizes these functions by executing the program stored in the memory 104 by the processor 102 (computer).

[0085] The processor 102 is also known as a CPU (Central Processing Unit), a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, or a DSP. As the memory 104, a semiconductor memory, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, or a DVD may be adopted. Adoptable semiconductor memories include RAM, ROM, flash memory, EPROM, and EEPROM, etc.

[0086] Figure 5 is a diagram showing another example of the hardware resources of the control device 10. In the example shown in Figure 5, the control device 10 includes a processing circuit 106 including a processor 102, a memory 104, and dedicated hardware 108. Figure 5 shows an example in which a part of the functions of the control device 10 is realized by the dedicated hardware 108. All of the functions of the control device 10 may be realized 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 can be adopted. Note that the modification examples of the hardware resources of the control device 10 described above can also be applied to the control device 10 of other embodiments described later.

[0087] 1-6-2. Torque Constant Identification Process The reference position for obtaining the current values Ium and Idm used in the torque constant identification process is preferably a position close to the intermediate position of the ascending and descending strokes where the torques Ur and -Ur become zero with respect to each other, but it does not necessarily have to be the intermediate position, and a position in the vicinity of the intermediate position may also be used. Further, the reference positions for obtaining the current values Ium and Idm may be symmetric positions with respect to the intermediate position. In this case, the torque constant identification unit 18 may, for example, obtain the current value Ium at a position that is -h from the intermediate position during constant speed operation by upward operation, and obtain the current value Idm at a position that is +h from the intermediate position during constant speed operation by downward operation.

[0088] 1-6-3. Inertia Identification Process In the inertia identification process, it is more preferable that the first position is closer to the fourth position, but it is not necessarily the same position. For example, a position near the fourth position may be sufficient. Similarly, it is preferable that the second position is the same as the third position, but it is not necessarily the same position. For example, a position near the third position may be sufficient.

[0089] It is more preferable that the acceleration aua during the upward operation is closer to the acceleration ada during the downward operation, but it is not necessarily the same value. For example, a value near the acceleration ada may be sufficient. Similarly, it is more preferable that the deceleration aud during the upward operation is closer to the deceleration add during the downward operation, but it is not necessarily the same value. For example, a value near the deceleration add may be sufficient.

[0090] Embodiment 2. 2-1. Features of the elevator in Embodiment 2 In the elevator of Embodiment 1 described above, the change in inertia J due to the load addition to the car 6 is not considered. In contrast, the elevator of Embodiment 2 is characterized by calculating the inertia J according to the car load and optimizing the control gain according to the car load.

[0091] FIG. 6 is a diagram showing the relationship between the car load W and the inertia J. In the example shown in this figure, the inertia J identified under three different load conditions is illustrated. When there are a plurality of inertia Js with different load conditions, the inertia J corresponding to the car load W can be identified by linearly interpolating them. When performing linear interpolation of inertia, it is sufficient to have the identified values of inertia J corresponding to at least two different load conditions. Also, the interpolation method is not limited to linear interpolation, and interpolation by any function may be used. The inertia J corresponding to the car load W is represented by the relational expression of the following equation (24).

[0092] J = A×W+B ···(24)

[0093] The coefficients A and B in the relational expression shown in Equation (24) can be obtained using the inertia J identified under different load conditions. In the example shown in FIG. 6, three points, i.e., the inertia J1 identified under the first load condition, the inertia J2 identified under the second load condition, and the inertia J3 identified under the third load condition, are obtained, modeled as a linear function of the car load W, and the coefficients A and B are obtained. Note that the linear interpolation method is not limited to the above, and the inertia may be identified under more load conditions and linearly interpolated by, for example, the least squares method. Alternatively, the inertia may be identified under two load conditions to obtain the coefficients A and B.

[0094] The gain update unit 22 calculates and stores the coefficients A and B. The gain update unit 22 calculates the inertia J corresponding to the car load W according to the relational expression shown in Equation (24), and updates the gain of the speed control unit 14 using the calculated inertia J. According to such control, even when the load condition of the car 6 changes, the speed control of the motor 3 can always be performed with the same control performance. Note that the calculation of the inertia corresponding to the load of the car 6 and the update of the speed control gain are performed before the elevator lands on the floor, the boarding and alighting of passengers are completed, and the travel starts.

[0095] 2-2. Specific processing executed in the control device in Embodiment 2 FIG. 7 is a flowchart of a routine executed in the control device of Embodiment 2. In the routine shown in FIG. 7, the case of identifying the inertia under three different load conditions is described as an example, but the number of load conditions is not limited as long as there are at least two. Note that the higher the number of load conditions, the higher the identification accuracy of the inertia, but the time required for identifying the inertia becomes longer. Therefore, the number of load conditions may be determined in consideration of these trade-offs.

[0096] In step S200 of the routine shown in FIG. 7, the elevator is operated in the upward and downward directions under the first load condition where the car load W is W1. Here, under the first load condition, the same processing as that from step S100 to step S114 of the routine shown in FIG. 3 is executed.

[0097] In the next step S202, the torque constant Kt is identified by the torque constant identification unit 18. Here, the same processing as that in step S116 of the routine shown in FIG. 3 is executed.

[0098] In the next step S204, the inertia J1 is identified by the inertia identification unit 20. Here, under the first load condition, the same processing as that in step S118 of the routine shown in FIG. 3 is executed.

[0099] In the next step S206, the elevator is operated in the upward and downward directions under the second load condition where the car load W is W2, which is different from W1. Here, under the second load condition, the same processing as that from step S100 to step S114 of the routine shown in FIG. 3 is executed.

[0100] In the next step S208, the inertia J2 is identified by the inertia identification unit 20. Here, under the second load condition, the same processing as that in step S118 of the routine shown in FIG. 3 is executed.

[0101] In the next step S210, the elevator is operated in the upward and downward directions under the third load condition where the car load W is W3, which is different from W1 and W2. Here, under the second load condition, the same processing as that from step S100 to step S114 of the routine shown in FIG. 3 is executed.

[0102] In the next step S212, the inertia J3 is identified by the inertia identification unit 20. Here, under the third load condition, the same processing as that in step S118 of the routine shown in FIG. 3 is executed.

[0103] In the next step S214, a relational expression between the car load W and the inertia J is calculated in the gain update unit 22. Here, the coefficients A and B in Expression (24) are calculated by linearly interpolating the inertias J1, J2, and J3.

[0104] As is clear from the above description, according to the elevator control device 10 of the second embodiment, the gain of the speed control unit 14 is updated using the inertia J identified according to the car load of the elevator 100. Thereby, since the control gain can be optimized according to the car load, it is possible to keep the control performance constant even when the car load changes.

[0105] Embodiment 3. 3-1. Features of the elevator control device in Embodiment 3 The elevator control device of Embodiment 3 is characterized in that, for the reference inertia identified in the state where the car load is zero, an inertia correction value corresponding to the car load W detected by the weighing device 8 is added to calculate the inertia according to the load of the car 6.

[0106] When the reference inertia when the car load is zero is J0 and the inertia increment due to the car load W is the inertia correction value JW, the overall inertia J can be expressed by the following Expression (25).

[0107] J = J0+JW ···(25)

[0108] Here, for example, when the elevator 100 is 1:1 roping, JW can be calculated by the following Expression (26) using the radius r of the sheave 2 and the car load W.

[0109] JW=W×r^2 ···(26)

[0110] Therefore, if the reference inertia J0 when the car load is zero is identified and the car load W is measured by the weighing device 8, the inertia J corresponding to the car load can be calculated using Expressions (25) and (26).

[0111] Specific Processing Executed in the Control Device in Embodiment 3 FIG. 8 is a flowchart of a routine executed in the control device of Embodiment 3. In step S300 of the routine shown in FIG. 8, the reference inertia J0 when the car load is zero is acquired. Here, the reference inertia J0 identified by executing the processing of the routine shown in FIG. 3 in a state where the car load is zero is acquired.

[0112] In step S302, when the elevator 100 lands on the floor and the boarding and alighting of passengers are completed, at the timing before traveling, the car load W is detected by the weighing device 8. In the next step S304, in the gain update unit 22, the inertia J is calculated by expressions (25) and (26) using the detected car load W. Then, in step S306, in the gain update unit 22, the speed control gain is updated with the inertia J calculated in step S304. When the update of the gain in this routine is completed, the elevator 100 travels.

[0113] As is clear from the above description, according to the elevator control device 10 of Embodiment 3, the inertia J is calculated using the reference inertia J0 identified in a state where the car load is zero and the car load W detected during the actual operation of the elevator 100. Thereby, the gain used in the speed control unit 14 can be appropriately updated according to the car load. Further, the identification of the inertia only needs to be performed in a state where the car load is zero, and the operation for the identification process can be simplified.

[0114] 4. Others Although the preferred embodiments and the like have been described in detail above, the present disclosure is not limited to the above-described embodiments and the like, and various modifications and substitutions can be made to the above-described embodiments and the like without departing from the scope described in the claims.

[0115] Hereinafter, aspects of the present disclosure will be summarized and described as appendices.

[0116] (Appendix 1) A speed control unit that calculates a current command value of the current flowing through the hoist so that the speed of the car traveling in the hoistway of the elevator becomes the speed command value; A current control unit that controls the hoist so that the actual current value flowing through the hoist becomes the current command value; A torque constant identification unit that identifies the torque constant of the hoist using the current value including the actual current value or the current command value and the car load acting on the car; An inertia identification unit that identifies the inertia of the elevator using the current value, the acceleration or deceleration of the car, and the torque constant; A gain update unit that updates the gain used in the calculation of the speed control unit using the inertia and the torque constant; An elevator control device comprising: (Appendix 2) The torque constant identification unit: Identifies the torque constant using the current value when the car passes the reference position in the hoistway at a constant speed during the upward operation of the elevator, the current value when the car passes the reference position at a constant speed during the downward operation of the elevator, and the car load. The elevator control device according to Appendix 1, configured as described above. (Appendix 3) The elevator control device according to Appendix 2, wherein the reference position is the intermediate position of the hoistway's up and down travel. (Appendix 4) The inertia identification unit: Acquires a first current value and a first acceleration, which are the current value and the acceleration when the car is accelerating in the upward direction at the first position of the hoistway; Acquires a second current value and a second deceleration, which are the current value and the deceleration when the car is decelerating in the upward direction at the second position of the hoistway; Calculates a first inertia identification value using the first current value, the first acceleration, the second current value, the second deceleration, and the torque constant; At the third position of the hoistway, obtain a third current value and a third acceleration, which are the current value and the acceleration when the car is accelerating in the downward direction. At the fourth position of the hoistway, obtain a fourth current value and a fourth deceleration, which are the current value and the deceleration when the car is decelerating in the downward direction. Calculate a second inertia identification value using the third current value, the third acceleration, the fourth current value, the fourth deceleration, and the torque constant. Identify the inertia based on the first inertia identification value and the second inertia identification value. An elevator control device according to any one of claims 1 to 3, configured as described above. (Appendix 5) The inertia identification unit An elevator control device according to claim 4, which identifies the average value of the first inertia identification value and the second inertia identification value as the inertia. (Appendix 6) The first position is the same as the fourth position, The second position is the same as the third position. An elevator control device according to claim 4 or 5. (Appendix 7) The first acceleration has the same value as the third acceleration, The second deceleration has the same value as the fourth deceleration. An elevator control device according to any one of claims 4 to 6. (Appendix 8) The inertia identification unit is configured to identify the inertia at each of a plurality of different car loads. The gain update unit Calculate the inertia for each car load by linearly interpolating the identified inertia, and update the gain for each car load. An elevator control device according to any one of claims 1 to 7, configured as described above. (Appendix 9) The inertia identification unit is configured to identify the inertia when the car load is zero. The gain update unit updates the gain according to the car load by using the inertia obtained by adding an inertia correction value corresponding to the car load to the inertia identified when the car load is zero. The elevator control device according to any one of Appendices 1 to 8, configured as described above. (Appendix 10) At the time of installing the elevator, The torque constant identification unit identifies the torque constant, and the inertia identification unit identifies the inertia. The elevator control device according to any one of Appendices 1 to 9, configured as described above.

Explanation of Signs

[0117] 1 Hoisting machine, 2 Sheave, 3 Electric motor, 4 Rotation sensor, 5 Main rope, 6 Car, 7 Counterweight, 8 Weighing device, 9 Current sensor, 10 Control device, 12 Speed detection unit, 14 Speed control unit, 16 Current control unit, 18 Torque constant identification unit, 20 Inertia identification unit, 22 Gain update unit, 100 Elevator, 102 Processor, 104 Memory, 106 Processing circuit, 108 Dedicated hardware

Claims

1. A speed control unit that calculates a current command value of the current flowing through a hoist so that the speed of a car traveling in an elevator hoistway becomes a speed command value; A current control unit that controls the hoist so that the actual current value flowing through the hoist becomes the current command value; A torque constant identification unit that identifies the torque constant of the hoist using the current value including the actual current value or the current command value and the car load acting on the car; An inertia identification unit that identifies the inertia of the elevator using the current value, the acceleration or deceleration of the car, and the torque constant; A gain update unit that updates the gain used in the calculation of the speed control unit using the inertia and the torque constant, comprising: The torque constant identification unit Identifies the torque constant using the current value when the car passes the reference position in the hoistway at a constant speed during the upward operation of the elevator, the current value when the car passes the reference position at a constant speed during the downward operation of the elevator, and the car load An elevator control device configured as described above.

2. The elevator control device according to claim 1, wherein the reference position is an intermediate position of the hoistway's up and down travel.

3. A speed control unit that calculates a current command value of the current flowing through a hoist so that the speed of a car traveling in an elevator hoistway becomes a speed command value; A current control unit that controls the hoist so that the actual current value flowing through the hoist becomes the current command value; A torque constant identification unit that identifies the torque constant of the hoist using the current value including the actual current value or the current command value and the car load acting on the car; An inertia identification unit that identifies the inertia of the elevator using the current value, the acceleration or deceleration of the car, and the torque constant; A gain update unit that updates the gain used in the calculation of the speed control unit using the inertia and the torque constant, comprising: The inertia identification unit Acquires a first current value and a first acceleration, which are the current value and the acceleration when the car is accelerating in the upward direction at a first position in the hoistway; Acquires a second current value and a second deceleration, which are the current value and the deceleration when the car is decelerating in the upward direction at a second position in the hoistway; Calculate a first inertia identification value by using the first current value, the first acceleration, the second current value, the second deceleration, and the torque constant. Obtain a third current value and a third acceleration, which are the current value and the acceleration when the car is accelerating in the downward direction at the third position of the hoistway. Obtain a fourth current value and a fourth deceleration, which are the current value and the deceleration when the car is decelerating in the downward direction at the fourth position of the hoistway. Calculate a second inertia identification value by using the third current value, the third acceleration, the fourth current value, the fourth deceleration, and the torque constant. Identify the inertia based on the first inertia identification value and the second inertia identification value. An elevator control device configured as described above.

4. The inertia identification unit The elevator control device according to claim 3, wherein the inertia is identified as the average value of the first inertia identification value and the second inertia identification value.

5. The first position is the same as the fourth position, The second position is the same as the third position The elevator control device according to claim 3.

6. The first acceleration has the same value as the third acceleration, The second deceleration has the same value as the fourth deceleration The elevator control device according to claim 3.

7. A speed control unit that calculates a current command value of the current flowing through the hoist so that the speed of the car traveling in the hoistway of the elevator becomes a speed command value, A current control unit that controls the hoist so that the actual current value flowing through the hoist becomes the current command value, A torque constant identification unit that identifies the torque constant of the hoist by using the current value including the actual current value or the current command value and the car load acting on the car, An inertia identification unit that identifies the inertia of the elevator by using the current value, the acceleration or deceleration of the car, and the torque constant, A gain update unit that updates the gain used in the calculation of the speed control unit by using the inertia and the torque constant, and is provided with The inertia identification unit is configured to identify the inertia at each of a plurality of different car loads, The gain update unit Calculates the inertia for each car load by linearly interpolating the identified inertias, and updates the gain for each car load. An elevator control device configured as described above.

8. A speed control unit that calculates a current command value of the current flowing through the hoist so that the speed of the car traveling in the hoistway of the elevator becomes the speed command value; A current control unit that controls the hoist so that the actual current value flowing through the hoist becomes the current command value; A torque constant identification unit that identifies the torque constant of the hoist using the current value including the actual current value or the current command value and the car load acting on the car; An inertia identification unit that identifies the inertia of the elevator using the current value, the acceleration or deceleration of the car, and the torque constant; A gain update unit that updates the gain used in the calculation of the speed control unit using the inertia and the torque constant, comprising: The inertia identification unit is configured to identify the inertia when the car load is zero; The gain update unit updates the gain according to the car load using the inertia obtained by adding an inertia correction value according to the car load to the inertia identified when the car load is zero; An elevator control device configured as described above.

9. At the time of installation of the elevator, The torque constant identification unit identifies the torque constant, and the inertia identification unit identifies the inertia; The elevator control device according to any one of claims 1 to 8, configured as described above.

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