Cage position control device

Abstract

Provided is a car position control device which can suppress an error caused by a position pattern. The car position control device controls the position of a car to follow a target position and comprises: a position pattern generation unit which generates a position pattern that represents a temporal transition of the position of the car from after the car starts to move a lifting / lowering distance until the car stops when the car moves the lifting / lowering distance towards a next floor; an error calculation unit which calculates a discretization error generated when the position pattern generating calculation is performed; a correction pattern generation unit which generates an error correction pattern that represents the temporal transition of the car position after the car starts to move the distance of the discretization error calculated by the error calculation unit until the car stops; and a target signal calculation unit which calculates the target position by reflecting the car position output from the position detector when the car stops at the floor prior to the corrected position pattern in which the position pattern overlaps the error correction pattern.

Description

Technical Field

[0001] The present disclosure relates to an elevator car position control device.

Background Art

[0002] Patent Document 1 discloses an elevator system. The elevator system includes an APS (Absolute Position Sensor), which is a position detector that constantly detects the absolute position of the car. In the elevator system, car position control can be realized by generating a target position of the car and causing the measured position of the car, which is the detection result of the APS, to follow the target position.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the car position control realized by the elevator system described in Patent Document 1, in order to generate a target position of the car, it is necessary to generate a position pattern, which is the time transition of the position from when the car starts moving to when it stops. The position pattern is generated by a processor for calculation based on software. However, since the position pattern is a function of time, a discretization error based on the calculation cycle of the processor may occur when the position pattern is generated. For this reason, an error may occur between the moving distance based on the position pattern and the actual lifting distance.

[0005] The present disclosure has been made to solve the above problems. An object of the present disclosure is to provide a car position Control device capable of suppressing the error due to the position pattern.

Means for Solving the Problems

[0006] The car position control device according to the present disclosure is a car position control device that controls the car so as to follow the position of the car output from a position detector that detects the position of the car in an elevator, and when the car moves a lifting distance toward the next floor, a position pattern generation unit that generates a position pattern showing the temporal change of the position of the car from the start to the stop of the movement of the lifting distance, an error calculation unit that calculates a discretization error between the distance shown in the position pattern and the lifting distance, which is an error generated when the calculation for generating the position pattern is performed, and a correction pattern generation unit that generates an error correction pattern showing the temporal change of the position of the car from the start to the stop of the movement of the distance of the discretization error calculated by the error calculation unit for the car, and a target signal calculation unit that calculates the target position by reflecting the position of the car output from the position detector when the car is stopped at the previous floor on the corrected position pattern in which the position pattern and the error correction pattern are superimposed.

Effect of the Invention

[0007] According to the present disclosure, the target position is calculated based on the corrected position pattern in which the position pattern and the error correction pattern are superimposed. Therefore, the error due to the position pattern can be suppressed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0009] The embodiments for carrying out the present disclosure will be described with reference to the accompanying drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals. The redundant description of such parts will be appropriately simplified or omitted.

[0010] Embodiment 1. Figure 1 shows the outline of an elevator system to which the car position Control device in Embodiment 1 is applied.

[0011] In the elevator system 1 of Figure 1, the configuration surrounded by the dashed line 1a is a mechanical configuration. In the elevator system 1, the hoistway 2 penetrates each floor of a building (not shown). A machine room (not shown) is provided directly above the hoistway 2. The motor 3a is provided in the machine room. The sheave 3b is connected to the rotating shaft of the motor 3a.

[0012] The main rope 4 is wound around the sheave 3b. The car 5 is provided inside the hoistway 2. The car 5 is suspended on one side of the main rope 4. The counterweight 6 is provided inside the hoistway 2. The counterweight 6 is suspended on the other side of the main rope 4.

[0013] The elevator system 1 further includes an angle detector 7, a position detector 8, and a control panel 9.

[0014] The angle detector 7 is attached to the motor 3a. For example, the angle detector 7 is an encoder (ENC). The angle detector 7 detects the rotation angle of the rotation axis of the motor 3a. The angle detector 7 outputs a signal corresponding to the detected rotation angle.

[0015] For example, the position detector 8 is provided in the car 5. The position detector 8 can constantly detect the absolute position of the car 5 in the hoistway 2. For example, the position detector 8 detects the absolute position of the car 5 by reading a detected object (not shown) provided from the upper end to the lower end of the hoistway 2. The absolute position of the car 5 is the value of the height of the car 5 in the hoistway 2. Note that the absolute position of the car 5 can also be expressed as the relative position of the car 5 with respect to the building. The position detector 8 is also called an APS. The position detector 8 outputs a signal indicating the detected absolute position of the car 5.

[0016] The control panel 9 is provided in the machine room. The control panel 9 is electrically connected to the motor 3a. The control panel 9 can control the elevator system 1 as a whole.

[0017] When the car 5 is in normal operation, the control panel 9 supplies a drive current to the motor 3a. The motor 3a rotates the rotation axis according to the drive current. The sheave 3b rotates in synchronization with the rotation axis of the motor 3a. The main rope 4 moves following the rotation of the sheave 3b. The car 5 and the counterweight 6 move up and down in opposite directions following the movement of the main rope 4. The angle detector 7 inputs an angle signal θ m indicating the rotation angle of the rotation axis of the motor 3a to the control panel 9. The position detector 8 creates a car position signal x car indicating the absolute position of the car 5 and inputs it to the control panel 9. At this time, for example, the position detector 8 creates the car position signal x car at a period shorter than the operation period inside the control panel 9 and inputs it to the control panel 9.

[0018] The control panel 9 receives the input angle signal θ m and the car position signal x carUsing at least one of them, the speed and position of the car 5 are controlled. When the control panel 9 moves the car 5 from one floor to the next floor, the speed of the car 5 is controlled based on a plurality of control modes. For example, the speed of the car 5 is controlled while switching between modes such as a constant acceleration mode in which the acceleration takes a constant value and a constant speed mode in which the speed takes a constant value. For example, when the car 5 lands on the landing position of a landing not shown, the control panel 9 performs landing control to the landing position.

[0019] The control panel 9 includes a car position control device 10 as a device for controlling the position of the car 5.

[0020] For example, the car position control device 10 is composed of each element provided in the electric substrate. Each element executes processing by a processor included in a processing circuit for calculation. Note that each element may include a processing circuit having no calculation function. The car position control device 10 is electrically connected to the motor 3a.

[0021] The car position control device 10 generates a target position of the car 5. A signal indicating the absolute position of the car 5 is input to the car position control device 10 from the position detector 8. The car position control device 10 controls the motor 3a so that the absolute position of the car 5 follows the target position. Specifically, the car position control device 10 generates a speed target signal v ref by the position control process of the car 5. The car position control device 10 generates a torque current target signal iq ref that follows the speed target signal v v_cont by the speed control process of the car 5. The car position control device 10 supplies a drive current to the motor 3a according to the torque current target signal iq v_cont .

[0022] The car position control device 10 includes a speed calculation unit 11, a first subtraction unit 12, a speed control unit 13, a current measurement unit 14, a current control unit 15, a target signal generation unit 16, a second subtraction unit 17, and a car position control unit 18.

[0023] The speed control process is mainly performed by a speed calculation unit 11, a first subtraction unit 12, a speed control unit 13, a current measurement unit 14, and a current control unit 15.

[0024] An angle signal θ from the position detector 8 is input to the speed calculation unit 11. m The speed calculation unit 11 calculates the angular velocity of the motor 3a from the angle signal θ and generates an angular velocity signal. The speed calculation unit 11 generates and outputs a car 5 speed signal v indicating the speed of the car 5 from the angular velocity signal. m m

[0025] For example, the first subtraction unit 12 is a subtractor that performs subtraction processing on the input signal. A speed target signal v is input to the first subtraction unit 12. A speed signal v is input to the first subtraction unit 12 from the speed calculation unit 11. The first subtraction unit 12 subtracts the speed signal v from the speed target signal v and outputs a speed error signal v. The speed error signal v indicates the difference between the target speed and the actual speed of the car 5. ref m ref m err err

[0026] A speed error signal v is input to the speed control unit 13 from the first subtraction unit 12. The speed control unit 13 generates and outputs a speed control signal iq based on the speed error signal v. The speed control signal iq is a signal calculated so that the difference indicated by the speed error signal v falls within a reference value. The speed control signal iq is the same as the torque current target signal iq. At this time, the speed control unit 13 performs proportional calculation, integral calculation, and differential calculation so as to satisfy various operating conditions such as the speed of the car 5 being a stable value, and generates the speed control signal iq. err err v_cont v_cont err v_cont v_cont v_cont

[0027] The current measurement unit 14 is a current sensor. The current measurement unit 14 is electrically connected between the motor 3a and the current control unit 15. The current measurement unit 14 measures the current value flowing between the motor 3a and the current control unit 15 and outputs the measurement result. For example, the current measurement unit 14 outputs a drive current signal iq indicating the q-axis current value among the measured current values.

[0028] The current control unit 15 receives a torque current target signal iq v_cont which is the speed control signal iq v_cont is input. The drive current signal iq is input to the current control unit 15 from the current measurement unit 14. The current control unit 15 supplies drive current to the motor 3a so that the drive current signal iq follows the speed control signal iq v_cont

[0029] In this way, in the speed control process, while the speed error signal v err is within the reference value, the speed signal v of the cage 5 m follows the speed target signal v ref such control is realized.

[0030] The position control process is mainly performed by the target signal generation unit 16, the second subtraction unit 17, and the cage position control unit 18.

[0031] The function of the target signal generation unit 16 is realized by software for the function being executed by the operation of the processor. The cage position signal x car from the position detector 8 is input to the target signal generation unit 16. The floor position signal x tgt is input to the target signal generation unit 16. The floor position signal x tgt is a signal indicating the position of the destination floor of the cage 5. The floor position signal x tgt is generated by a control system device higher than the cage position control device 10 inside the control panel 9. For example, when the cage 5 is stopped at a certain floor, the next floor position signal x tgt of the cage 5 is generated and input to the target signal generation unit 16. The target signal generation unit 16 compares the cage position signal x car with the floor position signal x tgt ​Using the above, the car position target signal x ref is generated and output. At this time, the target signal generation unit 16 corrects the discretization error caused by the software operation processing cycle, and the car position target signal x ref with the correction reflected is generated.

[0032] The second subtraction unit 17 is a subtractor that performs subtraction processing on the input signal. The second subtraction unit 17 receives the car position target signal x ref from the target signal generation unit 16. The second subtraction unit 17 receives the car position signal x car from the position detector 8. The second subtraction unit 17 subtracts the car position signal x ref from the car position target signal x car and outputs the car position error signal x err . The car position error signal x err indicates the difference between the target position and the actual absolute position of the car 5.

[0033] The car position control unit 18 receives the car position error signal x err from the second subtraction unit 17. The car position control unit 18 generates a car position control signal x err based on the car position error signal x cont . The car position control signal x cont is a signal calculated so that the car position error signal x err converges to zero. Note that the car position control unit 18 generates the car position control signal x cont as the speed target signal v ref and inputs it to the first subtraction unit 12. That is, the car position control unit 18 generates a car position control signal x ref having the same signal characteristics as the speed target signal v cont .

[0034] In this way, in the position control process, control is realized such that the car position error signal x err converges to zero, that is, the car position signal x car follows the car position target signal x ref . At this time, in the speed control process, the car position control signal x ref is used as the speed target signal vcont is input. In this case, the car position control device 10 executes control to function so that the car position error signal x err converges to zero. Therefore, the car position signal x car exactly follows the car position target signal x ref without error. For example, in the elevator system 1, an error in the landing position generated by disturbances such as friction acting on the car 5, elongation and contraction of the rope, etc. is suppressed. Note that the control becomes a type-1 position control loop. Therefore, even if a detection delay in the absolute position of the car 5 occurs, an increase in the control deviation is suppressed.

[0035] Next, the target signal generation unit 16 will be described with reference to FIG. 2. FIG. 2 is a block diagram showing the target signal generation unit of the car position control device in Embodiment 1.

[0036] As shown in FIG. 2, the target signal generation unit 16 includes a signal holding unit 161, a third subtraction unit 162, a transition time calculation unit 163, a position pattern generation unit 164, an error calculation unit 165, a correction pattern generation unit 166, and a target signal calculation unit 167.

[0037] The signal holding unit 161 has a sample-and-hold function. The car position signal x car is input to the signal holding unit 161. When the car 5 (not shown in FIG. 2) stops at the landing position, the signal holding unit 161 holds the car position signal x car at the landing position. The signal holding unit 161 holds the value of the car position signal x car at the previous landing position until the car 5 arrives at the next landing position. The signal holding unit 161 outputs the held value as an initial car position signal x ini indicating the position of the car 5.

[0038] For example, the third subtraction unit 162 is a subtractor that performs subtraction processing on the input signal. The initial car position signal x is input to the third subtraction unit 162 from the signal holding unit 161 iniis input. Before the cage 5 starts to move to the next floor, the third subtraction unit 162 receives the next floor position signal x tgt indicating the landing position of the next floor. When the next floor position signal x tgt is input, the third subtraction unit 162 subtracts the initial cage position signal x tgt from the next floor position signal x ini and outputs the lifting distance signal x dis . The lifting distance signal x dis indicates the distance that the cage 5 moves when moving to the next floor.

[0039] The transition time calculation unit 163 receives the lifting distance signal x dis from the third subtraction unit 162. When the lifting distance signal x dis is input, the transition time calculation unit 163 calculates the transition time T dis which is the time to transition from a certain control mode A to the next control mode B for a plurality of control modes of the cage 5 based on the lifting distance signal x AB . At this time, the transition time calculation unit 163 calculates each set of transition times including a plurality of transition times required to transition a plurality of control modes. The transition time calculation unit 163 outputs a signal indicating the set of transition times.

[0040] The position pattern generation unit 164 receives a signal indicating the set of transition times from the transition time calculation unit 163. When the signal is input, the position pattern generation unit 164 generates and outputs a position pattern based on the set of transition times. The position pattern is the time evolution of the position of the cage 5 from the start of the movement of the lifting distance to the stop. For example, the position pattern is represented by a numerical value corresponding to the position of the cage 5 at a certain time. The position of the cage 5 is the relative position with reference to the position of the departure floor. The start time of the position pattern is set to the time when the cage 5 starts to move. The start time is the first transition time included in the transition time. The end time of the position pattern is the predicted time when the cage 5 arrives at the next floor position. The end time is the last transition time included in the set of transition times.

[0041] A signal indicating a set of transition times is input from the transition time calculation unit 163 to the error calculation unit 165. When the signal is input, the error calculation unit 165 calculates the value of the discretization error. The discretization error is an error in distance that may occur due to the calculation cycle of the processing circuit, the sampling cycle of each numerical value, the numerical processing method employed in the calculation, etc. when the position pattern is generated. The discretization error is an error resulting from the discretization process executed during the calculation. The distance indicated by the discretization error is the difference between the distance that the cage 5 moves according to the position pattern generated by the position pattern generation unit 164 and the floor-to-floor distance shown in x dis This indicates the difference from the floor-to-floor distance shown in. The error calculation unit 165 outputs a signal indicating the discretization error.

[0042] A signal indicating a set of transition times is input from the transition time calculation unit 163 to the correction pattern generation unit 166. A signal indicating the discretization error is input from the error calculation unit 165 to the correction pattern generation unit 166. The correction pattern generation unit 166 generates and outputs an error correction pattern based on the set of transition times and the discretization error. Similar to the position pattern, the error correction pattern is the time evolution of the position of the cage 5 from when the cage 5 starts moving by the distance of the discretization error until it stops. For example, the error correction pattern is represented by a numerical value corresponding to the position of the cage 5 at a certain time. The position of the cage 5 is a relative position with 0 as the reference. The error correction pattern is a pattern for correcting the discretization error.

[0043] The initial cage position signal x ini is input from the signal holding unit 161 to the target signal calculation unit 167. A signal indicating the position pattern is input from the position pattern generation unit 164 to the target signal calculation unit 167. A signal indicating the error correction pattern is input from the correction pattern generation unit 166 to the target signal calculation unit 167. Note that a signal indicating the position of the cage 5 shown in the position pattern and a signal indicating the position of the cage 5 shown in the error correction pattern at a certain time may be input to the target signal calculation unit 167.

[0044] The target signal calculation unit 167 superimposes the position pattern and the error correction pattern to generate a corrected position pattern. The corrected position pattern is a position pattern in which the position of the car 5 shown in the position pattern is corrected by the position of the car 5 shown in the error correction pattern. The target signal calculation unit 167 transfers the initial car position signal x ini The target signal calculation unit 167 adds the initial car position signal x to the corrected position pattern at each specified period. ini The signal indicating the position to which the value is added is the cage position target signal x ref For example, the specified period is a calculation period of the process performed by the target signal generating unit 16.

[0045] Next, the principle of the discretization error calculated by the error calculation section 165 will be described.

[0046] The process of generating the position pattern is realized by executing a program included in the software by a processor. The processor executes the process for each unique calculation period. Since the position pattern is a function of time and the calculation period is regarded as a sampling period, the calculation of the position pattern may have a sampling error with respect to an ideal value. Furthermore, the numbers used in the calculation and the numbers indicating the results of the calculation are rounded off to a specified significant figure. In particular, the value of the transition time may be converted to an integer. Therefore, the generated position pattern may include a quantization error. Therefore, the position pattern may include a discretization error including such a sampling error and quantization error.

[0047] For example, the effect of discretization error is most noticeable when the position pattern is calculated in the constant speed mode i where the speed of the car 5 is at its maximum value. mode_i is shown below in (1).

[0048]

number

[0049] In equation (1), v max is the maximum speed of the cage 5 in the constant speed mode i. T ij is the time when the transition is made from the constant speed mode i to the next mode j. T hi is the time when the transition is made from the mode h before the constant speed mode i to the constant speed mode i.

[0050] For example, when integer arithmetic instead of floating-point arithmetic is performed in software, T ij and T hi are calculated as integer values. In this case, the term (T ij -T hi ) in equation (1) may include a discretization time error. This is due to the difference between the true values of T ij and T hi and their integerized values. When the discretization time error, which is this difference, is denoted as Δt e_i , the calculation result of the total moving distance x mode_i in the constant speed mode i is a value that includes an individual discretization error x e_i with respect to the true value of the distance that the cage 5 should move in mode i. The individual discretization error x e_i is represented by the following equation (2).

[0051]

Equation

[0052] Such individual discretization errors can occur in each of a plurality of control modes in the position pattern. The individual discretization error can be calculated from the time during which the corresponding control mode continues. The discretization error x e is the sum of the individual discretization errors that occur in a plurality of control modes. That is, the discretization error x e is the discretization error included in the entire position pattern.

[0053] Based on the above principle, the error calculation unit 165 calculates the discretization error corresponding to a certain position pattern from the set of transition times.

[0054] Next, with reference to FIG. 3, the relationships among a plurality of control modes, position patterns, and error correction patterns will be described. FIG. 3 is a diagram showing an example of a control mode, a position pattern, and an error correction pattern set by the cage position control device according to the first embodiment.

[0055] FIG. 3(a) shows the relationship between a plurality of control modes and transition times. That is, FIG. 3(a) shows the time transition of a plurality of control modes. The vertical axis represents the mode number of the control mode. The horizontal axis represents time. Here, the time axis on the horizontal axis includes both the time T [s: second] corresponding to the position pattern and the time T' [s: second] corresponding to the error correction pattern. The starting time 0 of the time T and the time T' is the same timing.

[0056] FIG. 3(b) shows the relationship between the acceleration of the cage 5 and time. That is, FIG. 3(b) shows an acceleration pattern that is the time transition of the acceleration of the cage 5. The vertical axis represents the acceleration of the cage 5. The horizontal axis represents the time T corresponding to the position pattern.

[0057] FIG. 3(c) shows the relationship between the speed of the cage 5 and time. That is, FIG. 3(c) shows a speed pattern that is the time transition of the speed of the cage 5. The vertical axis represents the speed of the cage 5. The horizontal axis represents the time T corresponding to the position pattern.

[0058] FIG. 3(d) is a position pattern. The vertical axis represents a numerical value indicating the position of the cage 5. The horizontal axis represents the time T corresponding to the position pattern.

[0059] FIG. 3(e) is an error correction pattern. The vertical axis represents a numerical value indicating the position of the cage 5. The horizontal axis represents the time T' corresponding to the error correction pattern.

[0060] For example, the speed value at each time in the speed pattern corresponds to the value obtained by differentiating the position pattern at each time. The acceleration value at each time in the acceleration pattern corresponds to the value obtained by differentiating the speed pattern at each time.

[0061] Next, each of the multiple control modes will be described.

[0062] Mode 0 is the mode in which the car 5 stops at a certain floor position. At the time T when the car 5 departs from the said floor, 01 it transitions from mode 0 to mode 1.

[0063] Mode 1 is the acceleration jerk mode. Jerk is the time change amount of acceleration. Jerk is also expressed as snap or jounce. In mode 1, the jerk is a positive constant value. In mode 1, the acceleration of the car 5 increases in proportion to time. Mode 1 continues until the time T when the specified maximum acceleration is reached. 12

[0064] At the time T 12 it transitions from mode 1 to mode 2. Mode 2 is the constant acceleration mode. In mode 2, the jerk is 0. The acceleration takes a constant value at the maximum acceleration. The speed of the car 5 increases in proportion to time.

[0065] At the time T 23 it transitions from mode 2 to mode 3. Mode 3 is the acceleration rounding mode. In mode 3, the jerk is a negative constant value. The acceleration decreases from the maximum acceleration. Mode 3 continues until the time T when the acceleration becomes 0. 34

[0066] At the time T 34 it transitions from mode 3 to mode 4. Mode 4 is the constant speed mode. In mode 4, the speed takes a constant value at the maximum speed v max

[0067] At the time T 45 it transitions from mode 4 to mode 5. Mode 5 is the deceleration rounding mode. In mode 5, the jerk is a negative constant value. The acceleration decreases from 0. The speed decreases from the maximum speed. Mode 5 continues until the time T when the specified minimum acceleration is reached. 56

[0068] ​​​​ At time T 56 it transitions from mode 5 to mode 6. Mode 6 is a constant acceleration deceleration Degree mode. In mode 6 the jerk becomes 0. The acceleration takes a constant value at the minimum acceleration. The speed of car 5 decreases in proportion to time.

[0069] At time T 67 it transitions from mode 6 to mode 7. Mode 7 is the landing jerk mode. In mode 7, the jerk is a positive constant value. The acceleration increases from the minimum acceleration towards 0. The speed of car 5 decreases gently. Mode 7 continues until the time T when the speed of car 5 becomes 0. That is, at time T 70 car 5 arrives at the landing position of the next destination floor and stops. 70 At time T

[0070] From the start of mode 1 to the end of mode 7, the position pattern transitions as shown in (d). As shown in FIG. 3, the acceleration, speed, and position in each mode all change continuously. In particular, the acceleration changes continuously. That is, the acceleration does not take discontinuous values at each transition time. Therefore, the waveforms shown by the speed and position are smooth and continuously changing without steps at any time. A comfortable riding experience can be provided to the passengers of car 5. The position pattern is generated based on an operation rule considered such that the acceleration, speed, and position become the waveforms shown in FIG. 3. For example, the position pattern is a cubic function with time as a parameter.

[0071] The transition time calculation unit 163 calculates each transition time based on the lifting distance that car 5 moves. At this time, the transition time calculation unit 163 calculates each transition time so that the position pattern can be generated based on the operation rule.

[0072] In the example shown in FIG. 3, mode 8 is a control mode indicating an error correction pattern. Mode 8 is executed in parallel with modes 1 to 7, which are control modes of the position pattern. Mode 8 starts at time T 34 and time T 45 and starts at time T 08 . Mode 8 continues until time T 70 , which is the same time T 80 . That is, while mode 8 is being executed, modes 5 to 7 are executed. The time zones of modes 5 to 7 are time zones where the acceleration is negative as a deceleration range and the speed changes. For example, mode 8 is executed in a time zone where the acceleration changes in the position pattern. Note that mode 8 may be executed in the time zone of the acceleration range, which is the time zone of modes 1 to 3. Also, mode 8 may be executed in any time zone that is not the time zone of the acceleration / deceleration range indicating the deceleration range or the acceleration range.

[0073] Time T 08 is set to the time retrogressed by the correction time T 70 from time T cr . The correction time T cr is the total time for executing the error correction pattern. So that mode 8 is executed in the time zone of FIG. 3, the correction pattern generation unit 166 sets the correction time T 08 to be just before time T 45 So as to generates the correction time T cr .

[0074] The target signal calculation unit 167 generates a corrected position pattern in which the waveform of the position pattern and the waveform of the error correction pattern are superimposed.

[0075] Next, the error correction pattern will be described with reference to FIG. 4. FIG. 4 is a diagram showing an example of an error correction pattern set by the cage position control device in the first embodiment.

[0076] FIG. 4 shows the waveforms of the time transitions of the respective numerical values in the error correction pattern.

[0077] ​Fig. 4(a) shows the relationship between the jerk of the basket 5 and time in the error correction pattern. That is, Fig. 4(a) shows the jerk pattern which is the time progression of the jerk of the basket 5. The vertical axis represents the jerk of the basket 5 in the error correction pattern. The horizontal axis represents the time T' corresponding to the error correction pattern.

[0078] Fig. 4(b) shows the acceleration pattern which is the time progression of the acceleration of the basket 5. The vertical axis represents the acceleration of the basket 5 in the error correction pattern. The horizontal axis represents the time T' corresponding to the error correction pattern.

[0079] Fig. 4(c) shows the speed pattern which is the time progression of the speed of the basket 5. The vertical axis represents the speed of the basket 5 in the error correction pattern. The horizontal axis represents the time T' corresponding to the error correction pattern.

[0080] Fig. 4(d) is the error correction pattern. The vertical axis is the numerical value indicating the position of the basket 5 in the error correction pattern. The horizontal axis represents the time T' corresponding to the error correction pattern.

[0081] The correction pattern generation unit 166 calculates the jerk value J e of the error correction pattern from the discretization error x cr and the correction time T e . For example, the correction pattern generation unit 166 calculates the jerk value J e based on the following formula (3).

[0082]

Equation

[0083] Note that the jerk value J e does not have to be the value shown in formula (3) as long as time integration is possible.

[0084] The correction pattern generation unit 166 generates a jerk waveform that transitions the jerk value by a specified interval. The correction pattern generation unit 166 generates a waveform of the position of the error correction pattern by performing a third-order time integration on the jerk waveform in each interval. Note that with respect to time, acceleration and velocity are the first-order integral value of jerk and the second-order integral value of jerk, respectively.

[0085] Since the error correction pattern is calculated as the third-order integral value of the jerk waveform, acceleration, velocity, and position in each mode all change continuously. In particular, acceleration changes continuously. That is, acceleration does not take discontinuous values between intervals. Therefore, the waveforms indicated by velocity and position, like the position pattern, have no steps at any time within the defined time range and change continuously and smoothly.

[0086] Also, the function of the acceleration pattern, where the error correction pattern is the second-order derivative function, is set such that the value becomes zero at both ends of the defined time range. That is, the integration constant when the jerk waveform is integrated once is set to zero, and the boundary condition of the acceleration pattern is set to zero. Therefore, within the defined time range, the acceleration of the error correction pattern does not change discontinuously.

[0087] In this example, the jerk waveform changes in four steps in a rectangular wave manner. Mode 8 is divided into four intervals from the first interval to the fourth interval. The times of the four intervals are each a time obtained by dividing the correction time T cr by one-fourth.

[0088] The first interval is the time period from time T 08 to time t1. In the first interval, the jerk becomes the maximum jerk value +J e The second interval is the time period from time t1 to time t2. In the second interval, the jerk becomes the minimum jerk value -J e The third interval is the time period from time t2 to time t3. In the third interval, the jerk becomes the minimum jerk value -J eIt becomes. The fourth section is the time zone from time t3 to time T 80 In the fourth section, the jerk becomes the maximum jerk value +J e At time T 80 the fourth section ends and the jerk becomes 0.

[0089] Based on the jerk waveform set as described above, an error correction pattern having a waveform of time transition as shown in FIG. 4 is generated.

[0090] Next, an example of the state transition of the control mode will be described with reference to FIG. 5. FIG. 5 is a bubble chart for explaining the outline of the state transition of the control mode set by the car position control device in the first embodiment.

[0091] The bubble chart shown in FIG. 5 corresponds to the examples shown in FIGS. 3 and 4. "Stand by" means mode 0 which is the standby state.

[0092] In this example, the state transition of the control mode is set such that the state transition A shown by the outer annular body in FIG. 5 and the state transition B shown by the inner annular body are mixed. The state transition A and the state transition B are independent of each other. The state transition A is a bubble chart corresponding to the position pattern. The state transition B is a bubble chart corresponding to the error correction pattern.

[0093] In the state transition A, the number of modes which is the number of states is 8. At time T 01 the control mode transitions from the standby state to mode 1. For example, time T 01 is the time when a command to generate a position pattern is issued from the control command system higher than the car position control device 10 to the car position control device 10. After mode 1, the control mode transitions in order up to mode 7. Thereafter, the control mode transitions from mode 7 to the standby state at time T 70 .

[0094] In state transition B, the number of modes, which is the number of states, is two. At time T on time axis T´ 08 at, the control mode of the error correction pattern transitions from the standby state to mode 8. After that, at time T 80 at, the control mode transitions from mode 8 to the standby state. At this time, mode 8 transitions independently of state transition A.

[0095] Note that in the examples shown in FIGS. 3 to 5, time T 80 is the same as time T 70 but mode 8 may transition from the standby state at any time zone included in state transition A. This is because the error correction pattern realized in mode 8 is generated as a pattern that does not cause unnecessary vibration of the basket 5 itself. For example, time T 08 may be the same as time T 01 That is, mode 8 may transition immediately after the basket 5 starts to accelerate.

[0096] Next, with reference to FIG. 6, the processing operation for generating the car position target signal x ref will be described. FIG. 6 is a flowchart for explaining the outline of the operation of the car position control device in Embodiment 1.

[0097] For example, the flowchart of FIG. 6 starts when a command to generate a position pattern is generated from a higher-level command System .

[0098] In the process of step S1, a floor position signal x tgt indicating the target floor position is input to the target signal generation unit 16 of the car position control device 10. The target signal generation unit 16 calculates the lifting distance. The target signal generation unit 16 calculates a set of transition times.

[0099] After that, the process of step S2 is performed. In step S2, the target signal generation unit 16 calculates the discretization error corresponding to the position pattern.

[0100] After that, the process of step S3 is performed. The target signal generation unit 16 initializes the processing time of the position pattern. Specifically, the target signal generation unit 16 sets the time T corresponding to the position pattern to 0.

[0101] After that, the process of step S4 is performed. The target signal generation unit 16 initializes the processing time of the error correction pattern. Specifically, the target signal generation unit 16 sets the time T' corresponding to the error correction pattern to 0.

[0102] After that, the process in which the state transition A for the position pattern is performed and the process in which the state transition B for the error correction pattern is performed branch. The process in which the state transition A is performed corresponds to steps S5 to S8. The process in which the state transition B is performed corresponds to steps S9 to S11. Note that each process from step S5 to S11 is performed for each operation cycle of the processor of the car position control device 10.

[0103] After the process of step S4 is performed, the process of step S5 is performed. In step S5, the variable T, which is the position pattern processing time, is incremented. Specifically, the time obtained by adding 1 to T becomes the next variable T.

[0104] After that, the process of step S6 is performed. In step S6, the target signal generation unit 16 generates a position pattern.

[0105] After that, the process of step S7 is performed. In step S7, the target signal generation unit 16 adds the initial car position signal x ini to the superimposed position pattern and error correction pattern, and generates and outputs the car position target signal x ref .

[0106] After that, the process of step S8 is performed. In step S8, the target signal generation unit 16 determines whether or not the variable T is greater than or equal to the value of the time T 70 which is the end time of the position pattern.

[0107] In step S8, if the variable T is smaller than the value of time T 70 , the processing after step S5 is performed. That is, the processing from step S5 to S8 is looped.

[0108] In step S8, if the variable T is greater than or equal to the value of time T 70 , the target signal generation unit 16 ends the process in which the state transition A is performed.

[0109] In this way, in steps S5 to S8, the waveform of the position pattern is generated. Also, in steps S5 to S8, the waveform indicating the time transition of the car position target signal x ref is generated.

[0110] Also, after the processing of step S4 is performed, the processing of step S9 is performed. In step S9, the variable T´, which is the processing time of the error correction pattern, is incremented. Specifically, the time when 1 is added to T´ becomes the next variable T´.

[0111] After that, the processing of step S10 is performed. Note that the processing of step S10 starts and is completed before the processing of step S7. In step S10, the target signal generation unit 16 generates an error correction pattern. The error correction pattern is used in the processing of step S7.

[0112] After that, the processing of step S11 is performed. In step S11, the target signal generation unit 16 determines whether the variable T´ is greater than or equal to the value of time T 80 , which is the end time of the error correction pattern.

[0113] In step S11, if the variable T´ is smaller than the value of time T 80 , the processing after step S9 is performed. That is, the processing from step S9 to S11 is looped.

[0114] In step S11, if the variable T´ is greater than or equal to the value of time T 80 , the target signal generation unit 16 ends the process in which the state transition B is performed.

[0115] According to the first embodiment described above, the car position control device 10 performs control to cause the car 5 to follow the position detected by the APS which is the position detector 8 to the target position. The car position control device 10 includes a position pattern generation unit 164, an error calculation unit 165, a correction pattern generation unit 166, and a target signal calculation unit 167. The car position control device 10 calculates the discretization error generated when generating the position pattern before the target position is generated. The car position control device 10 reflects the discretization error when generating the target position from the position pattern. At this time, the car position control device 10 generates an error correction pattern based on the discretization error and superimposes it on the position pattern. The car position control device 10 reflects the position of the car 5 on the previous floor on the corrected position pattern which is the result of the superposition, and generates the target position. Therefore, the error due to the position pattern can be suppressed. In particular, when applied to a car position control device in which the arithmetic processing is executed in integer type instead of floating point type due to the performance of the processor, the error is effectively suppressed. As a result, the accuracy of the position control of the car 5 can be improved. Further, the error correction pattern is not executed before and after the position pattern in terms of time, but is superimposed on the position pattern. Therefore, it is possible to suppress an increase in the movement time of the car 5 for correcting the discretization error. As a result, the convenience of the passengers is improved.

[0116] Also, the error correction pattern is a function of time. The acceleration pattern obtained by second-order differentiating the function of the error correction pattern is continuous at any time within the defined time range. The acceleration pattern has a value of zero at both ends of the defined time range. That is, in the error correction pattern, the time transition of the acceleration has a smooth waveform because it does not change discontinuously. If the time transition of the acceleration changes discontinuously, the passengers can feel Significant car vibration in the car 5, and the riding comfort of the car 5 deteriorates. In this case, the passengers feel uneasy. The error correction pattern in the present disclosure can suppress the occurrence of deterioration of the riding comfort and the like.

[0117] Also, the position pattern and the error correction pattern are functions of time. The position pattern has an acceleration / deceleration range that is an acceleration range and a deceleration range where the value of acceleration is non-zero for a period of time. The time range of the error correction pattern is defined to include the time period of the acceleration range or the deceleration range. That is, the movement for correcting the discretization error is executed in parallel while the cage 5 is accelerating or decelerating. Therefore, the movement time of the cage 5 can be shortened as compared with the case where the movement for correcting the discretization error is executed separately from the position pattern. Also, in the error correction pattern for correcting the discretization error, acceleration and deceleration of the cage 5 are required. By performing the acceleration and deceleration in the error correction pattern within the acceleration range or the deceleration range, the acceleration and deceleration in the error correction pattern are masked by the acceleration and deceleration in the position pattern. That is, it is possible to suppress the passengers from feeling the acceleration and deceleration in the error correction pattern. As a result, it is possible to suppress the deterioration of the riding comfort of the cage 5 due to the error correction pattern.

[0118] Note that the waveform of the error correction pattern does not have to be the waveform shown in FIG. 4 as long as it does not induce vibrations above a specified level in the cage 5.

[0119] Next, an example of the hardware constituting the cage position control device 10 will be described with reference to FIG. 7. FIG. 7 is a hardware configuration diagram of the cage position control device in the first embodiment.

[0120] Each function of the cage position control device 10 can be realized by a processing circuit. For example, the processing circuit includes at least one processor 100a and at least one memory 100b. For example, the processing circuit includes at least one dedicated hardware 200.

[0121] When the processing circuit includes at least one processor 100a and at least one memory 100b, each function of the car position control device 10 is realized by software, firmware, or a combination of software and firmware. At least one of the software and the firmware is described as a program. At least one of the software and the firmware is stored in at least one memory 100b. The at least one processor 100a realizes each function of the car position control device 10 by reading and executing the program stored in the at least one memory 100b. The at least one processor 100a is also referred to as a central processing unit, a processing device, an arithmetic device, a microprocessor, a microcomputer, or a DSP. For example, the at least one memory 100b is a non-volatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, or an EEPROM, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, or a DVD.

[0122] When the processing circuit includes at least one dedicated hardware 200, the processing circuit is realized by, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof. For example, each function of the car position control device 10 is realized by the processing circuit respectively. For example, each function of the car position control device 10 is realized by the processing circuit collectively.

[0123] Regarding each function of the car position control device 10, a part may be realized by dedicated hardware 200 and the other part may be realized by software or firmware. For example, the function of the current control unit 15 is realized by a processing circuit as dedicated hardware 200, and the functions other than the function of the current control unit 15 may be realized by the at least one processor 100a reading and executing the program stored in the at least one memory 100b.

[0124] In this way, the processing circuit realizes each function of the car position control device 10 by hardware 200, software, firmware, or a combination thereof.

Industrial Applicability

[0125] As described above, the car position control device according to the present disclosure can be used in an elevator system.

Explanation of Signs

[0126] 1 Elevator system, 1a Mechanical configuration, 2 Hoistway, 3a Motor, 3b Sheave, 4 Main rope, 5 Car, 6 Counterweight, 7 Angle detector, 8 Position detector, 9 Control panel, 10 Car position control device, 11 Speed calculation unit, 12 First subtraction unit, 13 Speed control unit, 14 Current measurement unit, 15 Current control unit, 16 Target signal generation unit, 17 Second subtraction unit, 18 Car position control unit, 161 Signal holding unit, 162 Third subtraction unit, 163 Transition time calculation unit, 164 Position pattern generation unit, 165 Error calculation unit, 166 Correction pattern generation unit, 167 Target signal calculation unit, 100a Processor, 100b Memory, 200 Hardware

Claims

1. A car position control device that controls the car so as to follow the position of the car output from a position detector that detects the position of the elevator car to a target position, a position pattern generation unit that generates a position pattern showing the time transition of the position of the car from the start to the stop of the movement of the lifting distance when the car moves a lifting distance toward the next floor, an error calculation unit that calculates a discretization error, which is an error that occurs when the operation for generating the position pattern is performed, between the distance shown in the position pattern and the lifting distance, a correction pattern generation unit that generates an error correction pattern showing the time transition of the position of the car from the start to the stop of the movement of the distance of the discretization error calculated by the error calculation unit, a target signal calculation unit that calculates the target position by reflecting the position of the car output from the position detector when the car is stopped at the previous floor on the corrected position pattern in which the position pattern and the error correction pattern are superimposed, A car position control device comprising the above components.

2. The car position control device according to claim 1, wherein the error correction pattern is a function of time, and the second-order differentiated function is continuous at any time within a defined time range and the value of the second-order differentiation at both ends of the defined time range is zero.

3. The position pattern is a function of time and has an acceleration / deceleration range that is a time zone where the value of the second-order differentiated acceleration function is not zero, The car position control device according to claim 1 or claim 2, wherein the error correction pattern is a function of time and the time range is defined so as to include the acceleration / deceleration range.

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