Elevator car and floor sill distance measuring method and device, medium and equipment

Abstract

The invention discloses a distance measuring method and device for an elevator car and a floor sill, a medium and equipment. The method comprises the steps that the elevator car transmits a terahertz wave signal and an ultrasonic signal to the floor sill; based on the received terahertz wave reflection signal and the ultrasonic wave reflection signal reflected by the floor sill, the initial distance between the elevator car and the floor sill is obtained; compensating the initial distance between the elevator car and the floor sill to obtain the compensated initial distance; and error correction is conducted on the compensated initial distance, so that the actual distance between the elevator car and the floor sill is obtained. According to the method, distance measurement is conducted by combining the terahertz wave signals and the ultrasonic wave signals, and the distance measurement precision of the elevator car and the floor sill can be improved.

Description

Technical Field

[0001] This application belongs to the technical field of elevator safety monitoring, and specifically relates to a method, device, medium, and equipment for measuring the distance between an elevator car and a floor sill. Background Art

[0002] Traditional methods for measuring the distance between an elevator car and a floor sill often use a single signal, such as only using terahertz wave signals for distance measurement. In an environment with high humidity, water molecules in the air will absorb the energy of terahertz waves, resulting in a rapid attenuation of the intensity of terahertz wave signals, thus affecting the distance measurement effect. Summary of the Invention

[0003] Aiming at the deficiencies in the prior art, the purpose of this application is to provide a method, device, medium, and equipment for measuring the distance between an elevator car and a floor sill, aiming to improve the measurement accuracy of the distance between the elevator car and the floor sill.

[0004] To achieve the above purpose, this application provides the following technical solutions:

[0005] A method for measuring the distance between an elevator car and a floor sill, the distance measurement method includes: transmitting terahertz wave signals and ultrasonic signals from the elevator car to the floor sill; based on the received terahertz wave reflection signals and ultrasonic reflection signals reflected by the floor sill, obtaining the initial distance between the elevator car and the floor sill; compensating the initial distance between the elevator car and the floor sill to obtain the compensated initial distance; and correcting the error of the compensated initial distance to obtain the actual distance between the elevator car and the floor sill.

[0006] Optionally, obtaining the initial distance between the elevator car and the floor sill includes: demodulating the terahertz wave reflection signal and the ultrasonic reflection signal respectively to obtain the phase information of the terahertz wave reflection signal and the ultrasonic reflection signal; and obtaining the initial distance between the elevator car and the floor sill based on the phase information of the terahertz wave reflection signal and the ultrasonic reflection signal.

[0007] Optionally, demodulating the terahertz wave reflection signal includes: mixing the terahertz wave reflection signal with a local oscillation signal to generate an intermediate frequency signal; filtering the intermediate frequency signal to obtain the filtered intermediate frequency signal, and the filtered intermediate frequency signal is expressed as:

[0008]

[0009] f IF =f THz -f LO

[0010] αφ THz =φ THz -φLO

[0011] Among them, A THz represents the amplitude of the terahertz wave reflection signal; A LO represents the amplitude of the local oscillation signal; π represents the pi; f IF represents the frequency of the intermediate frequency signal; t represents time; φ THz represents the phase of the terahertz wave reflection signal; f THz represents the frequency of the terahertz wave reflection signal; f LO represents the frequency of the local oscillation signal; φ LO represents the phase of the local oscillation signal; αφ THz represents the phase difference of the intermediate frequency signal;

[0012] Demodulating the ultrasonic reflection signal includes:

[0013] Mixing the ultrasonic reflection signal with a reference signal to obtain a mixed signal;

[0014] Filtering the mixed signal to obtain a baseband signal, and the baseband signal is expressed as:

[0015]

[0016] αφ US = φ US - φ ref

[0017] Among them, A US represents the amplitude of the ultrasonic reflection signal; φ US represents the phase of the ultrasonic reflection signal; t represents time; A ref represents the amplitude of the reference signal; φ ref represents the phase of the reference signal; αφ US represents the phase difference of the baseband signal.

[0018] Optionally, compensating the initial distance between the elevator car and the floor sill to obtain a compensated initial distance, including: performing linear displacement compensation on the initial distance to obtain a first compensation distance; performing rotational angle compensation on the first compensation distance to obtain a second compensation distance; compensating the second compensation distance in combination with environmental parameters to obtain a third compensation distance.

[0019] The present application also provides a ranging device for an elevator car and a landing sill, the ranging device comprising: a signal transmitting module for transmitting a terahertz wave signal and an ultrasonic signal from the elevator car to the landing sill; a first acquisition module for acquiring an initial distance between the elevator car and the landing sill based on the received terahertz wave reflection signal and ultrasonic reflection signal reflected by the landing sill; a second acquisition module for compensating the initial distance between the elevator car and the landing sill to obtain a compensated initial distance; and a correction module for correcting the error of the compensated initial distance to obtain the actual distance between the elevator car and the landing sill.

[0020] The present application also provides a storage medium comprising instructions which, when run on a computer, cause the computer to execute the method as described in any one of the preceding items.

[0021] The present application also provides an electronic device, the electronic device comprising: a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein when the processor executes the program, the method as described in any one of the preceding items is implemented.

[0022] Compared with the prior art, the beneficial effects brought by the present application are as follows:

[0023] The present application measures the distance between the elevator car and the landing sill by combining multi-modal signals of terahertz waves and ultrasonic waves, and utilizes the complementary advantages of the two in physical properties to achieve high-precision measurement of the distance. The present application also compensates and corrects the initially calculated distance, effectively overcoming multiple influences, thereby providing a more accurate and stable distance detection solution in a complex and variable actual application environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic flow chart of a ranging method for an elevator car and a landing sill provided by an embodiment of the present application;

[0025] Figure 2 is a schematic structural diagram of a ranging device for an elevator car and a landing sill provided by another embodiment of the present application;

[0026] Figure 3 is a schematic structural diagram of a storage medium provided by another embodiment of the present application;

[0027] Figure 4 is a schematic structural diagram of an electronic device provided by another embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] Specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Although specific embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present application can be more thoroughly understood and the scope of the present application can be fully communicated to those skilled in the art.

[0029] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different terms to refer to the same component. The specification and claims do not use the difference in terms as a way to distinguish components, but use the difference in the functions of components as the criterion for distinction. As mentioned throughout the specification and claims, "comprising" or "including" is an open-ended term and should be interpreted as "including but not limited to". The subsequent description in the specification is a preferred implementation manner for implementing the present application, but the description is for the purpose of the general principles of the specification and is not used to limit the scope of the present application. The protection scope of the present application shall be determined by the scope defined by the appended claims.

[0030] For the convenience of understanding the embodiments of the present application, the following will further explain with specific embodiments as examples in combination with the accompanying drawings, and each accompanying drawing does not constitute a limitation on the embodiments of the present application.

[0031] Figure 1 It is a method for measuring the distance between an elevator car and a landing sill provided by an exemplary embodiment of the present application, including the following steps:

[0032] S1: Activate the quantum dot modulated terahertz emitter and the piezoelectric ultrasonic transducer array installed in the elevator car, and emit terahertz wave signals and ultrasonic signals to the landing sill. Before emission, it is necessary to modulate the terahertz wave signals and ultrasonic signals (for example, pulse interleaving modulation technology, Pulse Interleaving) can be used to achieve spatio-temporal synchronization between the two;

[0033] S2: Based on the received terahertz wave reflection signal and ultrasonic reflection signal reflected by the landing sill, obtain the initial distance between the elevator car and the landing sill;

[0034] S3: Compensate the initial distance between the elevator car and the landing sill to obtain the compensated initial distance;

[0035] S4: Correct the error of the compensated initial distance to obtain the actual distance between the elevator car and the landing sill.

[0036] This application measures the distance between the elevator car and the landing sill by combining the multi-modal signals of terahertz waves and ultrasonic waves. Utilizing the complementary advantages of their physical properties, it can achieve high-precision measurement of the distance between the elevator car and the landing sill.

[0037] In another exemplary embodiment, in step S2, the obtaining of the initial distance between the elevator car and the landing sill includes the following steps:

[0038] S21: Demodulate the terahertz wave reflection signal and the ultrasonic wave reflection signal respectively to obtain the phase information of the terahertz wave reflection signal and the ultrasonic wave reflection signal.

[0039] In this step, the terahertz wave reflection signal is demodulated in the following manner:

[0040] First, mix the terahertz wave reflection signal with the local oscillation signal to generate an intermediate frequency signal, where,

[0041] The terahertz wave reflection signal s THz (t) is expressed as:

[0042] s THz (t) = A THz cos(2πf THz t + φ THz )

[0043] where, A THz represents the amplitude of the terahertz wave reflection signal; f THz represents the frequency of the terahertz wave reflection signal; φ THz represents the phase of the terahertz wave reflection signal; t represents time; π represents the ratio of the circumference of a circle to its diameter.

[0044] The local oscillation signal s LO (t) is expressed as:

[0045] s LO (t) = A LO cos(2πf LO t + φ LO )

[0046] where, A LO represents the amplitude of the local oscillation signal; f LO represents the frequency of the local oscillation signal; φ LO represents the phase of the local oscillation signal; π represents the ratio of the circumference of a circle to its diameter; t represents time.

[0047] The intermediate frequency signal is expressed as:

[0048] s IF (t) = s THz (t) · s LO (t)

[0049] Secondly, the high-frequency components in the intermediate-frequency signal are filtered out by a low-pass filter to obtain the intermediate-frequency signal s after the high-frequency components are filtered out, which is expressed as: IF (t), expressed as:

[0050]

[0051] f IF = f THz - f LO

[0052] Δφ THz = φ THz - φ LO

[0053] Among them, f IF represents the frequency of the intermediate-frequency signal; φ THz represents the phase of the terahertz wave reflection signal; φ LO represents the phase of the local oscillation signal; Δφ THz represents the phase difference of the intermediate-frequency signal.

[0054] Furthermore, the ultrasonic reflection signal is demodulated in the following manner:

[0055] First, the ultrasonic reflection signal is mixed with a reference signal. Among them, the ultrasonic reflection signal s US (t) is expressed as:

[0056] s US (t) = A US cos(2πf US t + φ US )

[0057] Among them, A US represents the amplitude of the ultrasonic reflection signal; f US represents the frequency of the ultrasonic reflection signal; φ US represents the phase of the ultrasonic reflection signal; t represents time.

[0058] The reference signal s ref (t) is a local oscillation signal generated synchronously with the ultrasonic reflection signal, and is expressed as:

[0059] s ref (t) = A ref cos(2πf ref t + φ ref )

[0060] Among them, A ref represents the amplitude of the reference signal; f ref represents the frequency of the reference signal; φ refRepresents the phase of the reference signal;

[0061] After mixing the ultrasonic reflection signal with the reference signal, a mixed signal s mix (t) is obtained, which is expressed as follows:

[0062] s mix (t) = s US (t)·s ref (t)

[0063] The high-frequency components in the mixed signal are filtered out by a low-pass filter, and the baseband signal s BB (t) is retained, which is expressed as:

[0064]

[0065] Δφ US = φ US - φ ref

[0066] Among them, Δφ US represents the phase difference of the baseband signal.

[0067] S22: Calculate the initial distance d0 between the elevator car and the landing sill, which is specifically calculated by the following formula.

[0068]

[0069] Among them, c represents the speed of light; π represents the pi; f THz represents the frequency of the terahertz wave reflection signal; f US represents the frequency of the ultrasonic reflection signal; Δφ THz represents the phase difference of the intermediate frequency signal; Δφ US represents the phase difference of the baseband signal.

[0070] Exemplarily, assume that Δφ THz = 0.785rad, f THz = 325.5GHz, Δφ US = 0.157rad, f US = 15.8MHz, c = 3×10 8 m / s, then there is:

[0071] That is, the initial distance between the elevator car and the landing sill is approximately 0.237 cm.

[0072] In this application, a terahertz wave signal and an ultrasonic wave signal are innovatively introduced simultaneously for ranging between the elevator car and the landing sill, which is considered based on the characteristics of these two signals. The terahertz wave and the ultrasonic wave have different penetration capabilities and reflection characteristics under different materials and environmental conditions. For example, the terahertz wave can provide high-resolution distance information but may be affected by environmental factors such as water vapor; while the ultrasonic wave is relatively unaffected by these factors but is less accurate and has lower resolution than the terahertz wave. Combining the two can complement each other and overcome the limitations of single-band technologies. In addition, for different environmental conditions, the performances of the terahertz wave and the ultrasonic wave also vary. For example, in an environment with higher humidity, the terahertz wave will be affected, while the ultrasonic wave can maintain better performance. Conversely, in some situations where it is not conducive to the propagation of the ultrasonic wave, the terahertz wave can still work properly. Therefore, the method of jointly measuring using the terahertz wave and the ultrasonic wave in this application can not only give full play to their respective advantages, make up for each other's deficiencies, but also overcome the complex and changeable environment, thereby providing accurate and reliable ranging results.

[0073] In another exemplary embodiment, in step S3, compensating the initial distance between the elevator car and the landing sill to obtain a compensated initial distance includes the following steps:

[0074] S31: Combining the environmental compensation matrix Performing linear displacement compensation on the initial distance d0 to obtain the initial distance after linear displacement compensation, denoted as the first compensation distance, which is specifically expressed as follows:

[0075]

[0076] where d trans represents the initial distance after linear displacement compensation, that is, the first compensation distance; δ x , δ y , δ z respectively represent the linear displacement compensation amounts along the X, Y, and Z axes, with the unit of micrometer (um), and are used to describe the deformation of the elevator car caused by temperature or humidity.

[0077] It should be noted that due to reasons such as mechanical structure changes, wear, or inaccuracies during manufacturing, the elevator car often generates linear displacement errors during operation. Through linear displacement compensation, the distance measurement errors caused by the movement of the elevator car in the linear direction can be corrected. If linear displacement compensation is not performed, even if the rotation angle and environmental factors are perfectly compensated, the distance measurement errors directly caused by mechanical components will still exist, thus affecting the final distance measurement accuracy.

[0078] It should also be noted that the environmental compensation matrix Δ is obtained through experimental calibration and data analysis, and is used to describe the influence of environmental factors on the measurement system. For example, under different environmental conditions, the distance value of the measurement target is measured, and the environmental parameters (such as temperature, humidity, and vibration) are recorded, and the experiment is repeated multiple times. Regression analysis is performed on the experimental data to establish a relationship model between the environmental parameters and the measurement error, such as:

[0079] δ x = a1·T + b1·H + c1·V

[0080] θ x = a2·T + b2·H + c2·V

[0081] Then the environmental compensation matrix can be generated according to the relationship model.

[0082] Among them, T represents temperature, H represents humidity, V represents vibration, and a1, b1, c1, a2, b2, c2 all represent coefficients.

[0083] S32: Perform rotation angle compensation on the initial distance d after linear displacement compensation in combination with the environmental compensation matrix trans to obtain the initial distance after rotation angle compensation, denoted as the second compensation distance, which is specifically expressed as follows:

[0084] d rot = d trans ·cos(θ x )·cos(θ y )·cos(θ z )

[0085] Among them, d rot represents the initial distance after rotation angle compensation, that is, the second compensation distance; θ x 、θ y 、θ z respectively represent the rotation angle compensation amounts around the X, Y, and Z axes, with the unit of radian (rad), and are used to describe the angular deviation of the elevator car caused by installation tilt or vibration.

[0086] In this embodiment, when the elevator car stops, it often does not completely parallel to the floor sill, so there is a certain tilt or rotation angle, which will cause the reflection paths of the terahertz wave signal and the ultrasonic wave signal to change, thus affecting the measurement result. Through the rotation angle compensation, the error caused by non-parallel alignment can be corrected, so that the reflected signal can more accurately reflect the actual distance. It should be noted that if the rotation angle compensation is not performed, even if the linear compensation and environmental parameter compensation are performed, the change in the signal reflection path will still cause deviation of the measurement result.

[0087] S33: Further compensate the initial distance d after rotation angle compensation in combination with environmental parameters (temperature, humidity, vibration) to obtain the initial distance after environmental parameter compensation, denoted as the third compensation distance, which is specifically expressed as follows: rot

[0088] d env = d rot + k1·T + k2·H + k3·V

[0089] where d env represents the initial distance after environmental parameter compensation, i.e., the third compensation distance; k1, k2, and k3 respectively represent the influence coefficients of temperature T, humidity H, and vibration V.

[0090] In this embodiment, changes in environmental conditions will affect the propagation characteristics of terahertz wave signals and ultrasonic wave signals. If environmental parameter compensation is not further performed on the basis of linear displacement compensation and rotation angle compensation, even if the other two compensation measures are done well, changes in the external environment may still cause large errors in the measurement results.

[0091] In summary, by sequentially implementing these three compensation measures, this application can effectively reduce the error sources of the elevator car from multiple aspects such as mechanical structure, physical position, and external environment. And each compensation focuses on solving a specific type of error. The combination of the three can comprehensively cover all the main factors that may affect the measurement accuracy of the distance between the elevator car and the floor sill, thereby maximizing the measurement accuracy.

[0092] In another embodiment, in step S4, the initial distance d after parameter compensation is error-corrected by constructing an error correction model as shown below: env

[0093]

[0094] f ML (d env , x; θ) = σ(W2·σ(W1·[d env , x] + b1) + b2)

[0095] g(d env , v(t), a(t)) = k v v(t) + k a a(t) + k d d env

[0096] where E(d env , x, t) represents the comprehensive error correction amount; f ML (d env , x; θ) represents the machine learning part; d env ​​Represents the third compensation distance; f ML (d env , x; θ) represents the error correction amount predicted by the machine learning model; x represents the environmental parameter vector; θ represents the parameter of the machine learning model; Represents the multi-sensor information fusion part; w i (t) represents the weight coefficient of the i-th sensor; E i (d env , x i ) represents the error correction amount provided by the i-th sensor; x i Represents the environmental parameter related to the i-th sensor; n represents the number of sensors; g(d env , v(t), a(t)) represents the dynamic compensation strategy; v(t) represents the change of the elevator speed with time t; a(t) represents the change of the elevator acceleration with time t; σ represents the activation function; W1 represents the weight matrix of the first layer; W2 represents the weight matrix of the second layer; b1 represents the bias term of the first layer; b2 represents the bias term of the second layer; k v 、k a 、k d Represent coefficients respectively, obtained through experiments.

[0097] In the above model, first, the trained machine learning model is used to predict the error correction amount, which can dynamically adjust the prediction result according to historical data and current environmental parameters, thereby improving the accuracy of error correction. Secondly, the multi-sensor information fusion part further corrects the error correction amount predicted by the machine learning model by integrating data from different types of sensors and using weighted averaging. Finally, based on the real-time monitored elevator speed and acceleration, the corrected error correction amount is compensated to ensure that the distance between the elevator car and the floor sill can also maintain high-precision measurement under dynamic conditions.

[0098] After obtaining the comprehensive error correction amount E(d env , x, t), it is combined with the initial distance d env after parameter compensation, and the actual distance between the elevator car and the floor sill can be obtained, which is specifically expressed as follows:

[0099] d final =d env +E(d env , x, t)

[0100] Among them, d final represents the actual distance between the elevator car and the floor sill.

[0101] Next, taking the calculated initial distance d0≈0.237cm as an example, the calculation process of step S3 is illustrated.

[0102] First, calculate the initial distance d after linear displacement compensation trans , that is

[0103]

[0104] Second, perform rotation angle compensation on the initial distance d after linear displacement compensation trans and calculate the initial distance d after rotation angle compensation rot , that is

[0105] d rot = d trans ·cos(θ x )·cos(θ y )·cos(θ z )

[0106] = 0.24074·cos(0.01)·cos(0.02)·cos(0.03)

[0107] = 0.24056 (cm)

[0108] Third, calculate the initial distance d after environmental parameter compensation env , that is

[0109] d env = d rot + k1·T + k2·H + k3·V

[0110] = 0.24056 + 0.001·25 + 0.0001·60 + 0.01·0.1

[0111] = 0.27256 (cm)

[0112] Furthermore, perform error correction on the initial distance d after environmental parameter compensation env , that is

[0113]

[0114] Finally, combine the above compensation results with the initial distance after parameter compensation to obtain the actual distance d between the elevator car and the landing sill final which is

[0115] d final = d env + E(d env , x, t) = 0.27370 + 0.27256 = 0.54626 (cm)

[0116] Based on the above examples, it can be seen that through multi-level compensation and error correction in this application, the measurement accuracy of the distance between the elevator car and the landing sill is significantly improved.

[0117] In addition, in the same environmental conditions, ranging experiments were conducted using only terahertz wave signals and only ultrasonic signals respectively in this application, and the results were compared with the reference values obtained by a high-precision measuring instrument. The comparison results are shown in Table 1 as follows:

[0118] Table 1

[0119]

[0120]

[0121] As can be seen from Table 1, in the same environment, the measurement result of the terahertz wave signal is 0.520 cm, with a negative error of -0.025 cm compared to the reference value of 0.54500 cm. The measurement result of the ultrasonic signal is 0.560 cm, with a positive error of +0.015 cm compared to the reference value of 0.54500 cm. By combining the terahertz wave signal and the ultrasonic signal in this application, the measurement result is 0.54626 cm, and the error is only -0.00126 cm, which is very close to the reference value, indicating that this application can improve the ranging accuracy between the elevator car and the landing sill compared with the traditional method.

[0122] In another exemplary embodiment, this application also provides a ranging device for an elevator car and a landing sill, as Figure 2 shown. The ranging device includes: a signal transmitting module 100, configured to transmit terahertz wave signals and ultrasonic signals from the elevator car to the landing sill; a first obtaining module 200, configured to obtain an initial distance between the elevator car and the landing sill based on the received terahertz wave reflection signals and ultrasonic reflection signals reflected by the landing sill; a second obtaining module 300, configured to compensate the initial distance between the elevator car and the landing sill to obtain a compensated initial distance; and a correction module 400, configured to correct the error of the compensated initial distance to obtain the actual distance between the elevator car and the landing sill.

[0123] Based on the above embodiments, refer to Figure 3 , a computer-readable storage medium of an exemplary embodiment of this application will be described. Please refer to Figure 3, which shows that the computer-readable storage medium is an optical disc 40, on which a computer program (i.e., program product) is stored. When the computer program is run by a processor, it will implement the steps recorded in the above method embodiments. For example, a terahertz wave signal and an ultrasonic wave signal are transmitted from the elevator car to the landing sill; based on the received terahertz wave reflection signal and ultrasonic wave reflection signal reflected by the landing sill, the initial distance between the elevator car and the landing sill is obtained; the initial distance between the elevator car and the landing sill is compensated to obtain the compensated initial distance; and the compensated initial distance is corrected for errors to obtain the actual distance between the elevator car and the landing sill. The specific implementation methods of each step will not be repeated here.

[0124] It should be noted that the computer-readable storage medium includes, but is not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical and magnetic storage media, which will not be elaborated one by one here.

[0125] Based on the above embodiments, the present application also provides an electronic device. The following will refer to Figure 4 to describe the electronic device for file downloading according to the exemplary embodiments of the present application.

[0126] Figure 4 shows a block diagram of an exemplary electronic device 50 suitable for implementing the embodiments of the present application. The electronic device 50 may be a computer system or a cloud server. Figure 4 The shown electronic device 50 is only an example and should not impose any limitations on the functions and usage scopes of the embodiments of the present application.

[0127] As Figure 4 shown, the electronic device 50 includes, but is not limited to: one or more processors or processing units 501, a system memory 502, and a bus 503 connecting different system components (including the system memory 502 and the processing unit 501).

[0128] The electronic device 50 typically includes a variety of computer system-readable media. These media can be any available media accessible by the electronic device 50, including volatile and non-volatile media, removable and non-removable media.

[0129] System memory 502 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 5021 and / or cache memory 5022. Electronic device 50 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, ROM 5023 may be used to read and write to non-removable, non-volatile magnetic media ( Figure 4 not shown, commonly referred to as a "hard disk drive"). Although not shown in Figure 4 , a disk drive for reading and writing to removable non-volatile disks (such as a "floppy disk"), and an optical disk drive for reading and writing to removable non-volatile optical disks (such as a CD-ROM, DVD-ROM or other optical media) may be provided. In these cases, each drive may be connected to bus 503 via one or more data media interfaces. System memory 502 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the embodiments of the present application.

[0130] A program / utilities 5025 having a set (at least one) of program modules 5024 may be stored, for example, in system memory 502, and such program modules 5024 include, but are not limited to: an operating system, one or more application programs, other program modules, and program data, and an implementation of a network environment may be included in each or some combination of these examples. Program modules 5024 generally execute the functions and / or methods in the embodiments described in the present application.

[0131] Electronic device 50 may also communicate with one or more external devices 504 (such as a keyboard, pointing device, display, etc.). Such communication may be through an input / output (I / O) interface 505. Also, electronic device 50 may communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via network adapter 506. As Figure 4 shown, network adapter 506 communicates with other modules of electronic device 50 (such as processing unit 501, etc.) via bus 503. It should be understood that although not shown in Figure 4 , other hardware and / or software modules may be used in conjunction with electronic device 50.

[0132] The processing unit 501 executes various functional applications and data processing by running the programs stored in the system memory 502. For example, it emits terahertz wave signals and ultrasonic signals from the elevator car to the landing sill; based on the received terahertz wave reflection signals and ultrasonic reflection signals reflected by the landing sill, it obtains the initial distance between the elevator car and the landing sill; compensates the initial distance between the elevator car and the landing sill to obtain the compensated initial distance; and corrects the error of the compensated initial distance to obtain the actual distance between the elevator car and the landing sill. The specific implementation manners of each step will not be repeated here. It should be noted that although several units / modules or sub-units / sub-modules of the file concurrent download device are mentioned in the above detailed description, this division is only exemplary and not mandatory. In fact, according to the embodiments of the present application, the features and functions of the two or more units / modules described above can be embodied in one unit / modules. Conversely, the features and functions of one unit / modules described above can be further divided and embodied by multiple unit / modules.

[0133] In the description of the present application, it should be noted that the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0134] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated here.

[0135] In several embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the couplings or direct couplings or communication connections shown or discussed with each other can be through some communication interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0136] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0137] In addition, in each embodiment of the present application, each functional unit may be integrated in a processing unit, may exist physically alone for each unit, or two or more units may be integrated in one unit.

[0138] If the above-mentioned function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a cloud server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0139] The above embodiments are only for illustrating the technical concept and features of the present application, and the purpose is to enable those who are familiar with this technology to understand the content of the present application and implement it accordingly. It should not be used to limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. A method for measuring the distance between an elevator car and a landing sill, characterized in that, The ranging method includes: Emitting a terahertz wave signal and an ultrasonic wave signal from the elevator car to the landing sill; Based on the received terahertz wave reflection signal and ultrasonic wave reflection signal reflected by the landing sill, obtaining the initial distance between the elevator car and the landing sill; Compensating the initial distance between the elevator car and the landing sill to obtain a compensated initial distance; Performing error correction on the compensated initial distance to obtain the actual distance between the elevator car and the landing sill.

2. The ranging method between an elevator car and a landing sill according to claim 1, characterized in that, The obtaining of the initial distance between the elevator car and the landing sill includes: Demodulating the terahertz wave reflection signal and the ultrasonic wave reflection signal respectively to obtain the phase information of the terahertz wave reflection signal and the ultrasonic wave reflection signal; Based on the phase information of the terahertz wave reflection signal and the ultrasonic wave reflection signal, obtaining the initial distance between the elevator car and the landing sill.

3. The ranging method between the elevator car and the landing sill according to claim 2, characterized in that, The demodulating of the terahertz wave reflection signal includes: Mixing the terahertz wave reflection signal with a local oscillation signal to generate an intermediate frequency signal; Filtering the intermediate frequency signal to obtain a filtered intermediate frequency signal, and the filtered intermediate frequency signal is expressed as: f IF = f THz -f LO αφ THz = φ THz - φ LO Among them, A THz represents the amplitude of the terahertz wave reflection signal; A LO represents the amplitude of the local oscillation signal; π represents pi; f IF represents the frequency of the intermediate frequency signal; t represents time; φ THz represents the phase of the terahertz wave reflection signal; f THz represents the frequency of the terahertz wave reflection signal; f LO represents the frequency of the local oscillation signal; φ LO represents the phase of the local oscillation signal; Δφ THz represents the phase difference of the intermediate frequency signal; The demodulating of the ultrasonic wave reflection signal includes: Mixing the ultrasonic wave reflection signal with a reference signal to obtain a mixed signal; Filtering the mixed signal to obtain a baseband signal, and the baseband signal is expressed as: Δφ US = φ US - φ ref Among them, A US represents the amplitude of the ultrasonic reflection signal; φ US represents the phase of the ultrasonic reflection signal; t represents time; A ref represents the amplitude of the reference signal; φ ref represents the phase of the reference signal; Δφ US represents the phase difference of the baseband signal.

4. The distance measurement method between the elevator car and the landing sill according to claim 1, characterized in that, The compensating of the initial distance between the elevator car and the landing sill to obtain a compensated initial distance includes: Performing linear displacement compensation on the initial distance to obtain a first compensated distance; Performing rotation angle compensation on the first compensated distance to obtain a second compensated distance; Compensating the second compensated distance in combination with environmental parameters to obtain a third compensated distance.

5. A distance measuring device for an elevator car and a landing sill, characterized in that, The ranging device includes: A signal transmitting module for emitting a terahertz wave signal and an ultrasonic wave signal from the elevator car to the landing sill; A first obtaining module for obtaining the initial distance between the elevator car and the landing sill based on the received terahertz wave reflection signal and ultrasonic wave reflection signal reflected by the landing sill; A second obtaining module for compensating the initial distance between the elevator car and the landing sill to obtain a compensated initial distance; A correction module for performing error correction on the compensated initial distance to obtain the actual distance between the elevator car and the landing sill.

6. A storage medium, characterized in that, It includes instructions which, when running on a computer, cause the computer to execute the method according to any one of claims 1 to 4.

7. An electronic device, characterized in that, The electronic device includes: A memory, a processor, and a computer program stored on the memory and executable on the processor, wherein When the processor executes the program, it implements the method according to any one of claims 1 to 4.

Images