WO2008077980A1

WO2008077980A1 - Method and system for determining position and speed of an elevating apparatus

Info

Publication number: WO2008077980A1
Application number: PCT/ES2007/000764
Authority: WO
Inventors: Alberto Maritxalar Goia; Miguel Encabo Elizondo; Luis Manuel Arnaiz Martinez
Original assignee: Orona, S. Coop.
Priority date: 2006-12-27
Filing date: 2007-12-27
Publication date: 2008-07-03
Also published as: ES2311388A1; ES2311388B1

Abstract

An elevating apparatus and method with system for determining position and/or speed, which determines, with high precision, the distance and/or relative speed of a car (20) for travelling through a well (23), via ultra wideband signal transmission means (5) transmitting a transmitted signal (18) towards a reflector (26), which reflects said signal for reception thereof in an antenna, thereby determining the time passed between the transmission and reception of each pulse of the signal, and thus determining the distance and position of the car (20) in the lift well (23).

Description

LIFTING EQUIPMENT AND METHOD WITH SYSTEM TO DETERMINE

POSITION AND / OR SPEED

D E S C R I P C I Ó N

OBJECT OF THE INVENTION

A first aspect of the present invention refers to a lifting apparatus with system for determining position and / or speed, and a second aspect of the invention refers to a method for determining position and / or speed of a lifting apparatus, having application, said two aspects, in the lifting industry, and preferably in the area of the elevators for the absolute determination of the position and / or the speed of at least one elevator car, both in a stop situation and in a situation of movement, with a high degree of precision and reliability.

BACKGROUND OF THE INVENTION

At present, in the lifting sector the need arises for having means for the detection and determination of both the position and the speed of the elevator cars that move inside an elevator shaft, so that an elevator control may have information regarding the position and the speed of travel that the cabin has at all times.

This data is necessary for the control in order that said control can determine, or decide, a sequence of orders or operations for whose determination is configured. Well, this information is used by the elevator control to make these decisions, usually during the operation of the elevator. Among the operations that the control determines or calculates, that is, the decisions that the control has to take, and that require considering the position and speed of a car, operations such as a car stop, a change of speed in certain points of the route, the detection of endpoints of the route both up and down, assign an order of attention of floor calls, determine the cabin speed along a movement or an opening or closing of doors only in certain allowed points of the route. All these decisions occur during normal operation of the elevator, during installation and also during maintenance operations. For example, when an elevator is in a stop situation, it is necessary to know the position of the cabin so that the control can determine, according to its configuration, the characteristics of the next movement.

In the lifting sector there are various types of devices configured to detect the position and speed of the elevator car.

One of these types comprises a plurality of reference marks along the gap, usually located in the guides, so that said reference marks are detected during the movement of the elevator by reading means that are integral with the cabin. The disadvantage that this type of devices presents is that the elevator control only has information regarding the position of the cabin in an area between two marks, but it cannot know the exact position of the cabin in the hollow when the cabin is in a position between the two marks. In order to solve this drawback, the arrangement of perforated ribbons that cover the entire gap is known so that when the cabin is moved the associated reader is configured to determine the displacement made by the cabin, although it is a complex system, which has little precision and a high cost.

On the other hand, when greater precision is required in determining the exact position of the cabin along its route, another type of device is used that includes an encoder, said devices being able to be located at various points of the installation, allowing the detect the movements of the cabin and determine its position. For example, one of these devices comprises a toothed guide located along the elevator shaft that has an absolute encoder mechanically connected, formed by various encoded discs configured to be read optically, as described in the PCT patent application. N ⁰ . WO 01/83349.

In order to reduce the number of elements that it is necessary to have in the recess in the devices intended to determine

The position and speed of an elevator car, and therefore reduce its costs without reducing its accuracy, the latest advances include various alternative devices to those previously exposed.

One of these alternative devices comprises a waveguide that uses a magnetostrictive material. The device comprises a delay line sensor formed by a wire or a tape of magnetostrictive material, transmission means and reception means. The transmission means produce a variation of the magnetic field by means of an electric pulse that, by effect of magnetoelastic coupling, generates an elastic wave in the magnetostrictive thread that propagates through the wire, being detected by the reception means, which calculate the position of the cabin depending on the time elapsed between the reception and the pulse generation.

Other devices include waveguides that use ultrasound, for which they require two transducers located at the ends of the hole. According to the offset of the signal received at the ends of the conductor, the distance at which a transmitter is located is calculated. The reception of the signal at both ends of the conductor is usually carried out by means of piezoelectric, inductive or capacitive elements. The main drawback of this type of device is that large errors occur in the measurement made, especially in the case that the length of the wire varies due to the effect of the temperature.

In US Patent No. ⁰ . US 5,736,695 describes a device that allows measuring the time elapsed between the sending of an acoustic signal, through a conductive wire of the signal, and the reception of said acoustic signal by two transducers located at the ends of the wire. Through this device it is not necessary to continuously compensate the system due to changes in the surrounding conditions, as is the case in the case of an ultrasonic propagation through the air. The disadvantage of this type of device is that they have a low temporal resolution, that is, during the time interval between two pulses the elevator can travel distances far greater than those necessary to guarantee resolutions of the order of 1 mm, because the The interval between the generation of two signals is always greater than the time taken by the signal to cover the entire length of the wire. The detected signals are used to stop two counters that are synchronized with a clock signal whose frequency has to be selected according to the required resolution, an aspect that adds enough complexity to the device.

In relation to the device described in the previous paragraph, Ia

US Patent No. ⁰ . US 6,366,532 describes a device that additionally comprises a calibration signal in order to compensate for variations produced by environmental parameters, such as for example the temperature or the stretching of the thread. For this, at one end of the wire where one of the receiving elements is located, a calibration pulse generation element is added. The device generates a synchronization pulse, and then launches a series of pulses on which an estimation of the position is made. The inconvenience of this device is its high cost and complexity, given that over long distances and with the cabin moving, it is not possible to wait until the pulse arrives to launch the next one, so that the device is not fast enough. In addition, when the cabin is in a stop situation, due to the rebounds of the acoustic signal in certain situations, problems in determining the position occur.

U.S. Patent No. ⁰ . US 5,883,345 describes a system for measuring distances through a transmitter located in a mobile element and two receivers located at both ends of a wire, allowing to calculate the distances between the emitter and each of the receivers separately to then rescale them depending on the total distance obtained. The main drawback of this system is that in the case that the length of the wire varies, for example as a consequence of the effect of the temperature, errors occur in the measurement obtained.

In addition, this system only obtains position information from the difference of the two reception times, so that an accidental displacement of one of the receivers or a change in the length of the wire produces errors that are not detected by the system.

In the patent application PCT N ⁰ . WO 03/043920 describes a system that allows to solve the problems of temporal resolution that have the devices that introduce synchronization pulses distanced in time, different from the measurement pulses, in which the interval between two synchronization pulses is greater than propagation time between the two ends of the route. Said problems occur as a consequence of the fact that the association of the reception pulses with the corresponding ones of transmission is only possible after the arrival of the corresponding synchronization pulses, so that the reflections cause interactions between the pulses and therefore produce distortions in them. The system described in the PCT Patent Application N ⁰ . WO 03/043920 sends pulses with a high cadence, generating a pulse sequence in which the time interval between successive pulses is different and the period of duration of the pulse sequence is greater than the maximum propagation time between the emitter and the receptor. The main drawback of this system is that there is an attenuation of the acoustic signal, which can be up to 50% over distances of 130 m, due to the remaining magnetization of the wire as a result of the field applied to create the signal acoustics. In the application of US Patent No. ⁰ . US 2003006101 describes a device for position detection, which solves the inconvenience of the attenuation of the acoustic signal that has the system described in the previous paragraph. The device is based on applying a field opposite to that applied for the generation of the acoustic signal to compensate for the remaining magnetization. The device also generates a certain number of acoustic compensation signals that are in contraphase with respect to the original signals, which adds considerable complexity to the device.

On the other hand, devices are also known which comprise the treatment of a laser signal, such as that described in US Patent No. ⁰ . US 6,437,315, in which a system is described to determine the position of elevators by means of a laser signal whose beam is modulated at two frequencies, obtaining with one of them an approximate measure of the position of the elevator car and with the other a precise measurement of said position. The main The disadvantage of this system is that it uses several frequencies, so it takes a long time to determine the position. This system is known as laser-SPPT, and even in the case of using two frequencies the system is not fast enough when the elevator is in motion.

In US Patent No. ⁰ . US 4,880,082 describes a method for determining the position of an elevator by means of a pulse counter indicating the speed of the elevator and the detection of the floors. For this, an accelerometer is used located in the elevator car that provides a series of pulses that indicate the position of the elevator and its speed. A disadvantage of this method is that it requires the use of floor or door area identifiers, in addition to the fact that it is not an absolute position system.

In U.S. Patent No. ⁰ . US 6,435,315 and US 6,612,403 describe absolute positioning systems for elevators that are based on a rail marked with codes readable by optical methods, consisting of photoreceptors or CCD or CMOS cameras. The codes are analyzed using character recognition techniques. The drawback that these systems have is that in order not to have resolution problems they require two separate cameras of a fixed distance, so that the measurement made by one of the cameras with respect to the other, called the reference camera, differs from the values of calibration corresponding to the fixed separation between the chambers.

Finally, there are devices of high complexity and cost, such as the one described in the PCT patent application. N ⁰ . WO

2004013576, where an absolute positioning system based on a coded magnetic tape or cylinder and a reading head of said codes is described. The coding is done on the basis of two polarities, and the device uses a single coding band. In addition, the device requires an electronic unit for the treatment and interpretation of codes.

DESCRIPTION OF THE INVENTION

A first aspect of the present invention relates to a lifting apparatus with system for determining position and / or speed, based on the principle of operation of a radar, that is to say that determines the position and / or the speed of objects by electromagnetic radiation.

Electromagnetic radiation is a combination of electric fields and oscillating magnetic fields that are perpendicular to each other and propagate through space carrying energy, without the need for a means for propagation, that is, they can propagate in a vacuum.

As Maxwell theorized, electromagnetic radiation is based on the fact that a time-varying electric field generates a magnetic field, and vice versa, its speed of propagation in a vacuum being the speed of light, that is, 299,792 Km / s, and its direction of propagation perpendicular to the oscillations of the electric and magnetic field, which in turn are perpendicular to each other. Electromagnetic radiation has applications and manifestations depending on its wavelength, from the light of the visible spectrum to radio waves or

TV, that is, television, so that the full range of wavelengths is known as electromagnetic spectrum.

Radio waves, also called herzian waves, are electromagnetic waves of less frequency, that is to say longer wavelength, and less energy than waves of the visible spectrum. The waves of Radio are generated by feeding an antenna with an alternating current. When an antenna conducts alternating current, the electromagnetic radiation propagates in the same frequency as the current. Also when an electromagnetic radiation affects an electric conductor, the surface electrons oscillate, generating an alternating current whose frequency coincides with that of the incident radiation. This phenomenon is what allows the antennas to act as emitters or receivers of electromagnetic radiation.

One type of radio waves are ultra-broadband radio frequency signals, known by its acronym UWB (ultrawideband), hereinafter UWB signals. Said UWB signals are radio signals that comprise short pulses, the duration of which is usually of the order of one nanosecond, and low power.

The Federal Communications Commission of the United States, in English Federal Communications Commission (FCC), defines a UWB signal as a transmission from an antenna in which the frequency bandwidth of the emitted signal is at least 20% of the value of a central frequency of said signal, or said bandwidth has a value not less than 500 MHz.

The bandwidth of a UWB signal is the frequency band in which the frequencies whose energy is 10 dB below the highest energy are. In addition, considering the upper and lower bandwidth limits of a UWB signal as f _H and f _L respectively, the fractional bandwidth is defined as the ratio 2 (f _H -f _L ) / (f _H + f _L ).

Thus, another definition of a UWB signal is that it has to have at least one of the following characteristics, a fractional bandwidth greater than or equal to 0.02, or a bandwidth greater than or equal to 500 MHz

The most common technique for generating UWB signals is to transmit pulses whose duration is in a range between several hundred picoseconds and several units of nanoseconds, so that the bandwidth of the resulting transmitted signal is in an order of magnitude of several GHz.

UWB signals use very low power and short pulse signals, so one of its main applications is to transfer data or information over a wide range of frequencies wirelessly. Usually the UWB signals provide a bandwidth that allows data transmission in a range of several hundred Mbps (Mega bits per second), being able to reach an order of several Gbps.

The approval by the Federal Communications Commission of the United States (FCC), in February 2002, of the commercial use of UWB signals due to its low risk for interference caused the use of this type of signals in multimedia system networks to the home, allowing secure wireless connections between high-definition devices without interference with other wireless devices, due to the combination of the characteristics of UWB signals, that is, a broad spectrum and very short pulses of low power.

Other known applications of UWB signals are related to the principle of radar operation, such as in the field of geological prospecting for obtaining devices that operate in contact with the ground in order to detect or obtain images of buried objects , and in the automotive sector to detect the position and movement of objects in the vicinity of a vehicle, allowing to avoid a collision as well as activate the airbag. An application of radio waves is radar, which is an acronym that comes from the English RAdio Detecting And Ranging, which means radio detection and location. The radar allows measuring distances by radio waves, and is based on the measurement of the time it takes to return a pulse of radio frequency sent by the radar, once reflected in an object whose position and / or speed is to be determined. The speed of propagation of radio waves is the speed of light, so that from said time of return of an impulse, the distance at which the object is located can be easily calculated. In relation to the direction in which the object is located, it is determined by the use of directive antennas, commonly called parabolic antennas, which can be easily oriented towards a reduced angle.

In accordance with the present invention, UWB signals are used to determine the position and / or the speed of an elevator car, according to the radar operating principle, set forth above.

In this way, the invention allows to establish the position of an object, with respect to a reference point, by means of the transmission of a UWB signal between the reference point and the object, and the reception of said signal at a known point. Since the UWB signals travel at the speed of light, the distance between the object and the reference point is calculated from time, commonly called flight time, which requires a pulse to travel or move between the object and the point reference. For the calculation of said time to be correct, the object and the means for receiving the UWB pulses must have synchronization signals, preferably clock signals.

The system for determining position and / or speed of the invention, incorporated in a lifting device allows several applications, in addition to controlling the position and the travel speed of at least one elevator car, such as determining the proximity of the ends of the shaft, detecting obstacles, controlling overspeed, and used as an anti-collision device in the case of a double cabin with independent movement located in the same elevator shaft.

The invention relates to a very high frequency bandwidth signal transmission system, comprising an electromagnetic wave emitter, radar type, and a receiver system. The possibility of the system comprising a reflector is contemplated.

The radar generates a pulsed electromagnetic wave, in order to obtain an initial reference, it emits and remains waiting for some echo to arrive. The shape over time of the envelope of the emitted signal can be very varied, contemplating the possibility that said shape is rectangular, triangular or sinusoidal. The pulses are emitted with a pulse repetition frequency, in English Press Repetition Frequency PRF, whose value is 1 / T where T is the period of a pulse.

For this application the objective is a conductive element that is placed at the point whose distance you want to measure. The material and the shape influence the intensity of the reflected signal.

For the measurement of the position and the speed, the transmission or emitter means generate an electromagnetic wave, in order to obtain an initial reference, once the system is transmitted it is waiting for the echo to arrive. From the processing of that echo signal the required parameters are calculated.

The calculation of the elevator position is made from the measurement of the time elapsed between the transmission or emission of a pulse and

The reception of your echo, taking into account that the reflection does not introduce no delay In the detection stage, a correlation module is preferably used, also called a correlative receiver, which in addition to improving the detection of weak signals, achieves a better spatial resolution than a threshold detector.

To calculate the speed of the elevator car in the shaft, techniques associated with the electromagnetic Doppler effect are used, in combination or as an alternative to techniques that are based on temporary derivation of the position data, this technique being the most used.

The pulse train may consist of one or several UWB pulses for each burst. The UWB pulses will depend on the frequency band used. Because it is usually a one-way system when using non-rotating antennas, it is not necessary to emit pulses at an excessively fast rate.

The emitted power will be relatively low, since the maximum range will generally not be too high. The maximum scope will be directly proportional to the size of the reflector and therefore the design of the reflector element will depend on the height of the building.

To implement the present invention, the use of any type of components based on commercial circuits or chips, such as DSPs, in Digital Signal Processor, or similar, or those that use FPGA technologies, in Field English is contemplated.

Programmahle Gate Array, or similar, or those integrated circuits that have been custom-made using ASlC technology or any other current equivalent technology.

The lifting device with system to determine position and / or speed that the invention proposes allows to determine distance and / or relative speed between at least a first reference point and at least a second reference point, in order to determine the position and / or the speed of at least one cabin that can move through an elevator shaft. For this, at least one of said reference points, either the first or the second, is located in said cabin.

The system of the invention comprises transmission means located at a first reference point, which are operatively oriented towards a second reference point. These transmission means allow transmitting to the second reference point a transmitted signal comprising ultra-broadband radio waves, ie a UWB signal.

According to a preferred embodiment of the invention, the system comprises at least one reflector, operatively located at a second reference point, in order that said reflector reflects the transmitted signal, that is to say the incident wave, as a directed reflected signal. , or oriented, towards at least one receiver that is located at a first reference point. Preferably the receiver is integral to the transmission means, and is configured to detect, or receive, the reflected signal.

Preferably the system comprises at least one antenna, preferably a directive or parabolic antenna, located at the first reference point and operatively oriented towards the reflector, each antenna comprising the transmission means and a receiver, allowing transmitting the transmitted signal and detecting the signal. reflected. The antenna has a sufficient bandwidth, and allows some orientation, so that in addition to improving the range it allows its orientation towards the transmission direction. Likewise, the possibility is contemplated that the system comprises at least one duplexer, or signal switch, configured to send the signal to be transmitted to an antenna and receive the reflected signal from said antenna, so that said duplexer allows to isolate the means of transmission of the receiver, allowing both subsystems to share the same antenna, in turn allowing the receiver to be isolated from the transmitted signal.

The reflector is preferably of electrically conductive material, contemplating the possibility that it has any size, geometry or configuration suitable to reflect the transmitted signal, such as a flat geometry or configuration, two plates with a V-shaped configuration or three irons with a corner configuration. Depending on the material, shape, size and orientation, the reflector reflects more or less energy to the transmission media. Its size will be as large as possible within the physical restrictions. In relation to its configuration there are certain embodiments that give better performance, that is, greater radar section. It is necessary to point out that the use of different reflector configurations is known and its variation would be obvious to an expert in the field.

On the other hand, according to a variant embodiment of the system that does not have a reflector, the possibility that at least one receiver is operatively located at a second reference point is contemplated, so that said receiver directly detects or receives said transmitted signal , being operatively synchronized with the transmission means.

In both embodiments, with and without reflector, the possibility of the system comprising at least one generator, or base clock, configured to generate cycles at a repetition frequency of pulses cyclically and continuously, as well as at least one timer configured to receive said pulse repetition frequency and generate at least one timing signal. Likewise, the system may comprise at least one ultra-wideband pulse generator, which receives the timing signal, and generates pulses of an ultra-wideband signal each time said timing signal arrives. The waveform generated will be the one that is optimal for the application, taking into account the propagation effects and the propagation method, considering the possibility that the shape of the envelope of the signal is rectangular, triangular or sinusoidal.

The system is configured to transmit an ultra-wideband signal every certain pulse period, designated with T, whose duration is designated with τ.

From the value of the pulse repetition frequency, the timer generates signals that cause the activation of the generator, in addition to generating a signal that uses a processor module as a reference for the timing, as explained in detail below.

Likewise, the system can comprise at least one correlation module, also called correlative receiver, configured to compare the signal detected by the receiver with a correlation pattern comprising the pulse of the ultra-wideband signal generated in the generator, operatively corrected. considering a distortion in the propagation of the transmitted signal. The correlation pattern is determined by the shape of the envelope of the signal, so that said pattern is not unique, but adapts to the characteristics of the signal.

In the event that the system comprises reflector the signal Detected by the receiver is the reflected signal, while in the case that the system has no reflector, the signal detected by the receiver is directly the transmitted signal.

In the detection stage, the correlation module is configured to compare an expected signal, taking into account the distortion caused in the transmission, with the signal detected or received. Depending on the data obtained in the correlation stage, the processor module is configured to calculate the distance at which the second reference point of the first reference point is located, which is preferably located in the cabin, taking the signal as reference of timing generated by the timer used in the transmission.

As mentioned, the system can comprise at least one processor module of the signal detected by the receiver, configured to receive the timing signal generated in the timer and the result obtained in the correlation module, allowing to determine, in a manner Snapshot for each pulse of the received signal, the time elapsed between those signals. The processor module is configured to determine the time elapsed between the transmission of a certain pulse as a transmitted signal and the detection, by the receiver, of said pulse as a received signal, based on the result of the correlation. In this way, the instantaneous distance between the first reference point and the second reference point is determined, that is between

The cabin and the hollow, which is considered an inertial reference system for the movement of the cabin, therefore determining the position of the cabin with respect to said inertial system.

Likewise, the processor module allows determining the relative speed between the first reference point and the second reference point, therefore allowing to determine the speed of travel of the cabin of the lifting apparatus. The Doppler frequency allows to calculate the speed of the cabin. In the reception, both the emitted pulse and the different bounces of the signal are observed, being the first to be received, which will also be the most powerful, which will be used to calculate the distance. The rest of the pulses must be correctly discarded in the processing stage.

Another possibility, simpler but of less accuracy, contemplated in the invention comprises estimating the speed of the cabin by means of the detection or measurement of changes of position of said cabin between successive measurements of position, by derivation of the position with respect to time.

It is necessary to consider that an antenna usually introduces a distortion in the form of the emitted pulse, normally related to the one derived from the form in time. This distortion is considered both in the generator and in the processor module, in order to adapt the generated pulse and its processing.

The possibility that the result of the position and speed calculation is shown or displayed on a display is contemplated.

Next, the measuring principle of the position and the travel speed of the cabin are described.

The calculation of the position between the transmission means and the second reference point, in which both the reflector and the receiver can be located, is based on measuring the time t _d that elapses between the pulse emitted until it is detected, considering the speed of propagation of the light in the medium, represented by c. 2 R „ct, fd = ^• => i? = -

When the signal is detected or received by the receiver, said signal being able to be the signal transmitted, in the case of not having a reflector, or the reflected signal, in case of having a reflector, in principle it is not possible to know if the echo corresponds to the last pulse sent or to any of the previous ones, a fact known as ambiguity. The radar is configured to detect only signal within the maximum unambiguous range, defined as:

_R _ ^{c T} = ^c max.n.α. ¹ J pΩJ?

For example, with a pulse repetition frequency of 1 MHz, the maximum unambiguous range is 150 m, so reducing the number of pulses emitted can increase that range.

To calculate the radar range based on the transmitted power and its parameters, the radar equation is used.

In the previous equation P ₁ - is the transmitted peak power; G ₁ - and G _R are the gain of the transmit and receive antennas, respectively; σ is the radar section of the metallic element, which depends on the material. and shape; λ is the wavelength of the emitted signal; τ is the pulse duration; n E¡ (n) refers to the gain obtained by the integration of several pulses; (SZN) ₁ is the necessary signal to noise ratio for the detection of the target; F is the noise of the receiver; and L _s and L _a are, respectively, the losses of the system and the propagation losses in the medium, excluding those of free space.

The principle from which the elevator speed in the gap is measured is based on the Doppler effect, which states that when a wave is emitted with a frequency f _{0 it} is reflected in a target, in this case the second reference point, and the reflected signal is lengthened or narrowed depending on the relative speed of said second reference point, and is detected with a frequency f different from the emission frequency f ₀ according to the following relationship.

The possibility that the system comprises at least one power amplifier configured to amplify the ultra-wideband signal generated in the generator and send it to the transmission means is contemplated. Before being transmitted, the ultra-wideband signal is amplified in the power amplifier so that it has a sufficient power level for its subsequent detection. Preferably the output level of the power amplifier is adjustable.

On the other hand, the possibility is contemplated that the system comprises at least one low noise amplifier, in English Low Noise Amplifier LNA, configured to filter and increase the signal detected by the receiver, and send it to said at least one module of correlation, all this introducing the lowest possible noise.

Additionally, the possibility that the system It comprises at least one control module of the lifting apparatus configured to receive and consider the position and / or the travel speed of said at least one cabin. In this way the result of the position and / or speed calculation is used as input to a control module.

It is also contemplated that the control module is configured to establish a position and / or a travel speed of said at least one cabin by its operation on the processor module, normally selected by an operator or user acting, selects and establishes said position and / or speed in the control module.

It is contemplated as a possibility that the system comprises at least one maintenance module configured to receive and store the position and / or travel speed data of said at least one cabin obtained in the processor module, also allowing to establish distances and positions of reference to perform specific functions and store them in said processor module. In this way, the result of the position and speed calculation is sent to the maintenance module for later inspection by the technical personnel responsible for the maintenance of the lifting device.

On the other hand, the amplification level of the power amplifier can be manually adjusted either by the maintenance module or by the control module.

The lifting apparatus of the invention allows detecting the position of at least one cabin with respect to an upper end and / or a lower end of the elevator shaft. It also allows detecting the travel speed of at least one cabin when said travel speed is greater than a certain speed safe, determining said speed value as a safety measure for elevator users.

The possibility is contemplated that the lifting apparatus can prevent the collision of a first cabin with a second cabin, configured to perform independent movements in an elevator shaft, by means of the action of the processor module.

In the present invention all possible embodiments are contemplated relative to the situation or location of at least a first reference point and at least a second reference point in the installation of the lifting apparatus, some of these embodiments being described below, it being understood that variation obvious from any of said situation options would be evident to an expert in the field, in view of the present invention.

In the first place, the possibility is considered that the transmission means are located at an upper end of the hole, being operatively oriented towards at least a second reference point located on a roof of at least one cabin.

According to a variant embodiment, at least a second reference point is located at the upper end of the hole, being operatively oriented towards the transmission means located on the roof of at least one cabin.

On the other hand, it is contemplated that the transmission means are located at a lower end of the gap, being operatively oriented towards a second reference point located on a floor of at least one cabin. Likewise, at least a second reference point may be located at the lower end of the hole, being operatively oriented towards the transmission means located on the floor of at least one cabin.

The possibility is contemplated that the lifting apparatus of the invention comprises a first cabin and a second cabin, both configured to move independently through the same elevator shaft, which is configured to accommodate said first cabin and second cabin. Well, the system comprises transmission means located on a first floor of the first cabin, which are operatively oriented towards a second reference point located on a second roof of the second cabin.

It is also contemplated as a variant that at least a second reference point is located on the first floor of the first cabin, being operatively oriented towards transmission means located on the second roof of the second cabin.

In addition to these two variants, and in either case, the possibility is contemplated that the system comprises second transmission means located at the upper end of the elevator shaft, being operatively oriented towards a second auxiliary reference point located in the First roof of the first cabin.

On the other hand, a second aspect of the present invention relates to a method for determining the position and / or speed of a lifting device, which comprises the use of ultra-low frequency radio signals of low power.

The method proposed by the invention comprises the following stages:

First, generate cycles at a certain pulse repetition frequency continuously.

Then the method comprises generating a timing signal, from the frequency of repetition of pulses in a timer, then ultra-wide band pulses are generated in a generator, from the timing signal.

Next, the method comprises amplifying the ultra-wideband signal generated in the generator, in a power amplifier, after

Which proceeds to transmit, by means of transmission located at a first reference point, the ultra-wideband signal transmitted to a second reference point.

Next, the method comprises detecting or receiving the ultra-wideband signal in a. receiver, after which a correlation is made between the ultra-wideband signal detected by the receiver and a correlation pattern based on the ultra-wideband signal generated in the generator.

The method comprises processing the signal received from the correlation module and determining the time between the transmission of a certain pulse and the reception of said pulse, considering the timing signal generated in the timer. Next, the distance and / or the relative speed between the first reference point and the second reference point is instantaneously determined for each pulse of the received signal.

It is contemplated as a possibility that after transmitting the ultra-broadband signal transmitted by means of transmission located at a first reference point, the method comprises reflecting said signal transmitted on a reflector, located at a second reference point, being reflected as a signal reflected towards a receiver located at the first reference point, said receiver being configured to detect said signal reflected.

Thus, according to the described invention, the lifting apparatus and method with system to determine position and / or speed that the invention proposes constitute an advance in the systems used up to now and satisfactorily solve the problem previously exposed in the line of achieve high precision with respect to systems comprising other types of radio signals that require longer duration pulses including continuous signals.

The use of radio signals of greater length, implies an effect of reflection of the signals with different surfaces of the installation that produce a distortion in the measurement of the received signal, especially in what refers to the time in which the peak of the signal is detected, which produces errors in the measurement of distance. On the contrary, the pulses of the UWB signal are so short that the entire set is usually processed by the receiving means in isolation, and therefore with greater precision, before the reflections of said signal reach the means of reception, because said reflections of the signal have to travel a path greater than that of the signal itself.

The UWB signal technology is different from the technology that includes wireless transmissions of narrower bandwidth. Instead of using a diffusion on different frequencies, UWB technology disseminates the signals over a very wide range of frequencies. UWB signals have very low power, which means that UWB transmissions may seem like background noise, so said UWB signals are usually very difficult to be detected.

UWB technology allows a high data transfer rate because its bandwidth is very wide, while the energy density spectrum is relatively low. For this reason the interference they produce, as well as the sensitivity to interference to which they are subjected, by signals of narrower bandwidth is very low, so that devices comprising UWB technology can coexist without risk of interference with other communication devices that comprise signals with narrower bandwidth, even if they use the same frequency range, that is, they have a very small impact with other systems in their environment.

The system of the invention does not have a high cost, since when using low power ultra-wideband UWB signal transceivers, they are cheaper and simpler to construct than narrowband transceivers. The devices that use UWB signals consume very little energy, becoming, for example, a ten-thousandth of the energy usually consumed by a mobile telephone terminal.

The lifting apparatus and method with system to determine position and / or speed that the invention proposes has a series of advantages by the fact of using UWB signals compared to conventional narrowband radar systems. In the first place, the system to determine the position and / or the speed is an absolute system, that is, in the event of a failure or loss of tension in the installation, when the system recovers, the system immediately recognizes the position of the elevator. In addition, the system minimizes the pulse repetition frequency, in English Press Repetition Frequency PRF, achieving high precision in the distance measurement, even in the order of millimeters. The resolution in determining the position and speed is better than those obtained by other means due to the use of very high frequencies and very short pulses.

In addition, the operation of the system is independent of the speed at which the elevator car moves, with high reliability and robustness.

The system suffers little interference due to atmospheric or environmental conditions, such as humidity, temperature or pressure, and the consequent dilation that these conditions produce in the materials.

The system of the invention has a lower cost and occupies less space than existing devices to determine position and / or speed, without requiring additional elements, such as guides, which reduces the cost of installation, being easy to calibrate and without requiring tools special.

The system is extremely versatile, allowing its installation in any type of elevator regardless of its characteristics, all with a very low and valid cost for any configuration of the elevator shaft.

DESCRIPTION OF THE DRAWINGS

To complement the description that is being made and in order to help a better understanding of the characteristics of the invention, according to a preferred example of practical realization thereof, a set of drawings is attached as an integral part of said description. Illustrative and not limiting, the following has been represented: Figure 1 shows a representation in time of the emitted UWB signal comprising the invention, which comprises UWB pulses every certain period, in which the duration of each pulse can be appreciated.

Figure 2.- Shows a schematic representation of the UWB pulses detected by the receiver, in this case with a rectangular envelope, and the correlation pattern used in the correlation module.

Figure 3, - Shows a block diagram with the main elements comprising the system of the invention, representing by arrows the relationship between the different elements.

Figure 4.- Shows a block diagram like that of figure 3 of a variant of the system of the invention.

Figure 5.- Shows a schematic representation of a section, according to an elevation view, of an elevator apparatus with a system for determining position and / or speed object of the invention, comprising a cabin located in an elevator shaft.

Figure 6 shows a schematic representation like that of Figure 5 of a variant embodiment of the lifting apparatus object of the invention.

Figure 7 shows a schematic representation like that of Figure 5 of another variant embodiment of the lifting apparatus, comprising two cabins located in the same elevator shaft.

Figure 8.- Shows a schematic representation like the one of

Figure 7 of another variant embodiment of the lifting apparatus of Ia invention.

PREFERRED EMBODIMENT OF THE INVENTION

In view of the aforementioned figures, it can be observed that in one of the possible embodiments of the first aspect of the invention, the lifting apparatus with system for determining position and / or speed allows determining the distance and / or the relative speed between a first point of reference and a second reference point (6), comprising a cabin (20) that is configured to move through an elevator shaft (23), where at least one of said first reference point and second reference point (6) of reference, is located in said cabin (20).

The system of the invention comprises transmission means (5) located at the first reference point, which are operatively oriented towards the second reference point (6). Said transmission means (5) are operatively oriented towards the second reference point (6), being configured to transmit a transmitted signal.

(18) comprising ultra-broadband radio waves, that is to say a signal in which the frequency bandwidth of the emitted signal is at least 20% of the value of a central frequency of said signal, or said width of band has a value not less than 500 MHz, that is a UWB signal

According to a preferred embodiment of the invention, shown in Figure 4, the system comprises a reflector (26), operatively located at the second reference point (6), said reflector (26) being configured to reflect the transmitted signal ( 18) as a reflected signal (19) operatively directed towards a receiver that is located at the first reference point, said receiver being configured to detect the reflected signal (19). The system comprises an antenna located at the first reference point and operatively oriented towards the reflector (26), said antenna comprising the transmission means (5) and the receiver, whereby the antenna is configured to transmit the transmitted signal (18 ) and detect the reflected signal (19).

As can be seen in Figure 4, the lifting apparatus with system to determine position and / or speed that the invention proposes comprises a duplexer (13) configured to send the signal to be transmitted (18) to the antenna and receive from said antenna. antenna Ia reflected signal (19).

Said duplexer (13) is configured to isolate the transmission means (5) of the receiver, allowing both subsystems to share the same antenna, and isolate the receiver from the transmitted signal (18).

Preferably, the reflector (26) is made of electric conductive material, contemplating the possibility that it has any size, geometry or configuration suitable to reflect the transmitted signal (18), such as a flat geometry or configuration, two plates with a shaped configuration of V or three plates with a corner configuration.

On the other hand, according to a variant embodiment of the invention, as shown in Figure 3, the system that has no reflector (26), the receiver being operatively located at the second reference point (6), so that said receiver is configured to detect the transmitted signal (18), being operatively synchronized with the transmission means (5).

In both embodiments, with and without reflector (26), shown in Figures 4 and 3 respectively, the system comprises a generator configured to generate cycles at a certain repetition frequency. of pulses (1) cyclically and continuously. In the preferred embodiment, shown in Figure 4, the signal detected by the receiver is the reflected signal (19), while in the variant shown in Figure 3 the signal detected by the receiver is directly the transmitted signal (18).

Likewise, the system comprises a timer (2) configured to receive the pulse repetition frequency (1) and generate at least one timing signal. In addition, the system comprises an ultra-wideband pulse generator (3), which receives the timing signal, and generates pulses of an ultra-wideband signal each time said timing signal arrives.

As can be seen in Figure 1, the system is configured to transmit an ultra-wideband signal every certain period of pulses (14), which have a certain duration (16).

From the value of the pulse repetition frequency (1), the timer (2) is configured to generate signals that activate the ultra-wide band pulse generator (3).

In addition, also in both embodiments, the system comprises a correlation module (8) configured to compare the signal detected by the receiver, represented in the graph on the left in the schematic diagram of Figure 2, with a correlation pattern (15 ), represented in the graph on the right, corresponding to the pulse of the ultra-wideband signal generated in the generator (3), operatively corrected considering a distortion in the propagation of the transmitted signal (18). The correlation module (8) is configured to compare an expected signal (17) with the detected or received signal. It is necessary to point out that the correlation pattern (15) is adapted to the shape of the envelope of the signal, which in the case represented in Figure 2 It has a rectangular shape.

The system also comprises a processor module (9) of the signal detected by the receiver, configured to receive the timing signal generated in the timer (2) and the result obtained in the correlation module (8). The processor module (9) is configured to determine, for each pulse of a detected or received signal, the time elapsed between the transmission of a certain pulse as a transmitted signal (18) and the detection, by the receiver, of said pulse as a signal received, based on the result of the correlation module (8). In this way the processor module (9) is configured to determine the distance between the first reference point and the second reference point (6). In addition, the processor module (9) is configured to determine the relative speed between the first reference point and the second reference point (6).

The result of the position and / or speed calculation can be shown or presented on a display (10), as can be seen in Figure 4.

In addition, the system comprises a power amplifier (4) configured to amplify the ultra-wideband signal generated in the generator (3) and send it to the transmission means (5), so that the signal has a sufficient power level for its subsequent detection. The output level of the power amplifier (4) is adjustable.

On the other hand, the system comprises a low noise amplifier (7) configured to filter and increase the signal detected by the receiver, and send it to the correlation module (8), introducing a minimum noise.

The system comprises a control module (11) of the apparatus Elevator configured to receive and consider the position and / or the travel speed of the cabin (20), so that the result of the calculation of position and / or speed is used as input to a control module (11).

The control module (11) is configured to establish a position and / or a cab travel speed (20) by its operation on the processor module (9).

On the other hand the system includes a maintenance module

(12) configured to receive and store the position and / or cab travel speed data (20) obtained in the processor module (9), allowing to establish distances and reference positions to perform specific functions and store them in said processor module ( 9), so that the result of the position and / or speed calculation is sent to the maintenance module (12) for later inspection, for example by the technical staff responsible for the maintenance of the lifting device.

The amplification level of the power amplifier (4) can be adjusted manually either by the maintenance module (12) or by the control module (11).

The lifting apparatus of the invention is configured to detect the position of at least one cabin (20) with respect to an upper end (24) and / or a lower end (25) of the elevator shaft (23).

Likewise, the system is configured to detect the travel speed of at least one cabin (20) when said travel speed is greater than a certain safe speed, said speed value being determined as a safety measure for elevator users. The lifting apparatus is configured to prevent the collision of a first cabin (20 ') with a second cabin (20 "), configured to perform independent movements in an elevator shaft (23), by means of the action of the processor module (9).

With respect to the location of at least a first reference point and at least a second reference point (6), in the installation of the lifting apparatus, the present invention contemplates different variants of embodiment, some of which are explained below.

According to the variant shown in Figure 5, the transmission means (5) are located at an upper end (24) of the recess (23), being operatively oriented towards a second reference point (6) located on a roof ( 21) of the cabin (20).

According to another variant embodiment, not shown, a second reference point (6) is located at the upper end (24) of the recess (23), being operatively oriented towards the transmission means (5) located in the ceiling ( 21) of the cabin (20).

On the other hand, in the variant represented in Figure 6, the transmission means (5) are located at a lower end (25) of the hole (23), being operatively oriented towards a second reference point (6) located in a floor (22) of the cabin (20).

According to another variant, not shown, the second reference point (6) is located at the lower end (25) of the recess (23), being operatively oriented towards the transmission means (5) located on the ground (22) of the cabin (20).

In the variant shown in Figure 7, the lifting apparatus of Ia The invention comprises a first cabin (20 ') and a second cabin (20 "), both configured to move independently through the same elevator shaft (23), which is configured to accommodate said first cabin (20') and second cabin (twenty"). This system comprises transmission means (5) located on a first floor (22 ') of the first cabin (20'), which are operatively oriented towards a second reference point (6) located on a second roof (21 ") of The second cabin (20 ").

In accordance with another variant, the second reference point (6) is not represented is located on the first floor (22 ') of the first cabin (20'), being operatively oriented towards transmission means (5) located on the second roof (21 ") of the second cabin (20").

It is contemplated that any of the last two variants described, one of them represented in Figure 7, additionally comprises second transmission means (5 ') located at the upper end (24) of the elevator shaft (23) , being operatively oriented towards a second auxiliary reference point (6 ') located in the first roof (21') of the first cabin (20 '), which has been represented in

Figure 8.

The method proposed by the invention comprises the following steps:

First generate cycles at a repetition frequency of pulses (1) continuously.

Then the method comprises generating a timing signal, from the pulse repetition frequency (1) in a timer (2), then ultra-wide band pulses are generated in a generator (3), from the signal of timing

Next, the method comprises amplifying the ultra-wideband signal generated in the generator (3), in a power amplifier (4), after which it is transmitted, by means of transmission (5) located at a first point of reference, the ultra-broadband signal transmitted (18) to a second reference point (6).

Next, the method comprises detecting or receiving the ultra-wideband signal in a receiver, after which a correlation is made between the ultra-wideband signal detected by the receiver and a correlation pattern (15) based on the band signal ultra wide generated in the generator (3), as shown in the schematic diagram of Figure 2.

The method comprises processing the signal received from the correlation module (8) and determining the time between the transmission of a certain pulse and the reception of said pulse, considering the timing signal generated in the timer (2). Next, the distance and / or the relative speed between the first reference point and the second reference point (6) is instantaneously determined for each pulse of the received signal.

It is contemplated as a possibility that after transmitting the transmitted ultra-broadband signal (18) by means of transmission (5) located at a first reference point, the method comprises reflecting said transmitted signal (18) in a reflector (26), located at a second reference point (6), being reflected as a reflected signal (19) towards a receiver located at the first reference point, said receiver being configured to detect said reflected signal (19).

In view of this description and set of figures, the person skilled in the art may understand that the embodiments of the invention that have been described can be combined in multiple ways within the object of the invention. The invention has been described according to some preferred embodiments thereof, but for the person skilled in the art it will be evident that multiple variations can be introduced in said preferred embodiments without exceeding the object of the claimed invention.

Claims

1.- Lifting device with system to determine position and / or speed, to determine distance and / or relative speed between at least a first reference point and at least a second reference point, comprising at least one movable cabin (20) by an elevator shaft (23), at least one of said reference points being located in said at least one, cabin (20), characterized in that it comprises transmission means (5), located in said at least one, first reference point, operatively oriented towards at least a second reference point (6), said transmission means (5) being configured to transmit a transmitted signal (18) comprising ultra-broadband radio waves towards said at least one, second reference point (6).

2. Elevator with system for determining position and / or speed, according to claim 1, characterized in that it comprises at least one reflector (26), operatively located in said at least one, second reference point (6), being configured said, at least one, reflector (26) to reflect the transmitted signal (18) as a reflected signal

(19), and at least one receiver located at the first reference point, said at least one receiver being configured to detect said reflected signal (19).

3.- Lifting device with system to determine position and / or speed, according to claim 2, characterized in that it comprises at least one antenna, which in turn comprises the transmission means (5) and at least one receiver, said configuration being configured, at least one, antenna for transmitting the transmitted signal (18) and receiving the reflected signal (19), being operatively oriented towards said at least one reflector (26) that is operatively located in said at least one, second point of reference (6).

4.- Lifting device with system for determining position and / or speed, according to claim 3, characterized in that it comprises at least one duplexer (13) configured to send said signal to be transmitted (18) to said antenna and receive at least one said, at least one, antenna the reflected signal (19), said at least one duplexer (13) being configured to isolate the transmission means (5) of the receiver and to isolate the receiver from the transmitted signal (18) .

5. Elevator with system for determining position and / or speed, according to any of claims 2 to 4, characterized in that said at least one reflector (26) operatively configured to reflect the transmitted signal (18), is of material electric conductor

6. Elevator with system for determining position and / or speed, according to any of claims 2 to 5, characterized in that said at least one reflector (26) operatively configured to reflect the transmitted signal (18), has a geometry flat.

7. Elevator with system for determining position and / or speed, according to any of claims 2 to 5, characterized in that said, at least one, reflector (26) operatively configured to reflect the transmitted signal (18), comprises two plates with a V-shaped configuration.

8. Elevator with system to determine position and / or speed, according to any of claims 2 to 5, characterized in that said at least one reflector (26) operatively configured to reflect the transmitted signal (18), comprises three plates with a corner configuration.

9.- Lifting device with system for determining position and / or speed, according to claim 1, characterized in that it comprises at least one receiver, operatively located in said at least one, second reference point (6), said said being configured at minus one, receiver to detect said transmitted signal (18) and operatively synchronized with the transmission means (5).

10.- Lifting device with system to determine position and / or speed, according to any of the preceding claims, characterized in that it comprises:

- at least one generator configured to generate cycles at a pulse repetition frequency (1) cyclically and continuously,

- at least one timer (2), configured to receive the pulse repetition frequency (1) and generate at least one timing signal,

- at least one ultra-wideband pulse generator (3), configured to receive the timing signal, and generate pulses of an ultra-wideband signal each time said timing signal arrives, - at least one correlation module ( 8) configured to compare the signal detected by the receiver with a correlation pattern (15) comprising the pulse of the ultra-wideband signal generated in said, at least one, generator (3) operatively corrected considering a distortion in the propagation of the transmitted signal (18),

- at least one processor module (9) of the signal detected by said at least one receiver configured to receive the timing signal generated in said at least one timer (2), the result obtained in said at least one , correlation module (8) and instantly determine for each signal pulse the time between the transmission and the detection, being configured the processor module (9) to determine the distance between said, at least one, first reference point and said, at least one, second reference point (6), said said being configured, at least one processor module (9) to determine , The relative speed between said, at least one, first reference point and said, at least one, second reference point (6), being configured to determine, therefore, the position and / or the travel speed of said , at least one, cabin (20) of the lifting apparatus.

11.- Lifting device with system to determine position and / or speed, according to claim 10, characterized in that it comprises at least one power amplifier (4) configured to amplify the ultra-wideband signal generated in said at least one generator (3) and send it to the transmission media (5).

12. Elevator with system to determine position and / or speed, according to any of claims 10 and 11, characterized in that it comprises at least one low noise amplifier (7) configured to filter and increase the signal detected by the receiver, and send it to said at least one correlation module (8).

13.- Lifting apparatus with system for determining position and / or speed, according to any of claims 10 to 12, characterized in that it comprises at least one control module (11) of the lifting apparatus configured to receive and consider the position and / or Ia travel speed of said at least one cabin (20).

14.- Lifting device with system for determining position and / or speed, according to claim 13, characterized in that said at least one control module (11) is configured to establish a position and / or a travel speed of said at least one cabin (20) by its operation on the processor module (9).

15.- Lifting device with system for determining position and / or speed, according to any of claims 10 to 14, characterized in that it comprises at least one maintenance module (12) configured to receive and store position and / or speed data. displacement of said at least one booth (20) obtained in the processor module (9) and to establish distances and reference positions to perform specific functions and store them in said processor module

(9).

16.- Lifting device with system for determining position and / or speed, according to any of claims 11 to 15, characterized in that the amplification level of the power amplifier (4) is manually adjustable by means of the maintenance module (12).

17. Elevator with system for determining position and / or speed, according to any of claims 11 and 15, characterized in that the amplification level of the power amplifier (4) is adjustable by means of the control module (11).

18.- Lifting device with system for determining position and / or speed, according to any of the preceding claims, characterized in that it is configured for the detection of the position of said, at least one, cabin (20) with respect to an upper end ( 24) and / or to a lower end (25) of the elevator shaft (23).

19.- Lifting device with system to determine position and / or speed, according to any of the preceding claims, characterized in that it is configured for the detection of a speed of displacement of said, at least one, cabin (20) greater than a certain safe speed.

20.- Lifting device with system to determine position and / or speed, according to any of the preceding claims, characterized in that it is configured to prevent the collision of a first cabin (20 ¹ ) with a second cabin (20 ") configured to perform movements independent in an elevator shaft (23), by means of said at least one processor module (9).

21. Elevator with system for determining position and / or speed, according to any of the preceding claims, characterized in that it comprises transmission means (5) located at an upper end (24) of the elevator shaft (23), being operatively oriented towards at least a second reference point (6) located on a roof (21) of said at least one cabin (20).

22.- Lifting device with system for determining position and / or speed, according to any of claims 1 to 20, characterized in that it comprises at least a second reference point (6) located at an upper end (24) of the recess (23) of elevator, being operatively oriented towards means, of transmission (5) located in a roof (21) of said, at least one, cabin (20).

23. Elevating apparatus with system for determining position and / or speed, according to any of claims 1 to 20, characterized in that it comprises transmission means (5) located at a lower end (25) of the elevator shaft (23), being operatively oriented towards at least a second reference point (6) located on a floor (22) of said at least one, cabin (20).

24. Lifting apparatus with system for determining position and / or speed, according to any of claims 1 to 20, characterized in that it comprises at least a second reference point (6) located at a lower end (25) of the recess (23) of elevator, being operatively oriented towards transmission means (5) located on a floor (22) of said, at least one, cabin (20).

25. Lifting device with system for determining position and / or speed, according to any of claims 1 to 20, comprising a first cabin (20 ') and a second cabin (20 ") configured to move independently through a gap (23) of an elevator configured to house said first cabin (20 ') and second cabin (20 "), characterized in that it comprises transmission means (5) located on a first floor (22') of the first cabin (20 '), being operatively oriented towards a second reference point (6) located in a second roof (21 ") of the second ^" cabin (20 ").

26.- Lifting device with system for determining position and / or speed, according to any of claims 1 to 20, comprising a first cabin (20 ') and a second cabin (20 ") configured to move independently through a gap (23) of elevator configured to accommodate said first cabin (20 ') and second cabin (20 "), characterized in that it comprises a second reference point (6) located on a first floor (22') of the first cabin (20 ') ), being operatively oriented towards transmission means (5) located in a second roof (21 ") of the second cabin (20").

27.- Lifting apparatus with system for determining position and / or speed, according to any of claims 25 and 26, characterized in that it comprises second transmission means (5 ') located at an upper end (24) of the elevator shaft (23) , being operatively oriented towards a second auxiliary reference point (6 ') located on a first roof (21') of the first cabin (20 ').

28.- Method for determining the position and / or speed of a lifting device, characterized in that it comprises the following stages:

- generate cycles at a pulse repetition frequency (1) continuously,

- generate a timing signal, from the pulse repetition frequency (1) in a timer (2), - generate ultra-wide band pulses in a generator (3), from

The timing signal,

- amplify the ultra-wideband signal generated in the generator

(3), in a power amplifier (4),

- transmit, by means of transmission (5) located at a first reference point, the ultra-broadband signal transmitted (18) to a second reference point (6),

- detect the ultra-broadband signal in a receiver,

- make a correlation between the ultra-wideband signal detected by the receiver and a correlation pattern (15) based on the ultra-wideband signal generated in the generator (3),

- process the signal received from the correlation module (8) and determine the time between the transmission of a certain pulse and the reception of said pulse, considering the timing signal generated in the timer (2), - determine, for each pulse of Received signal, distance and / or relative speed between the first reference point and the second reference point (6).

29.- Method for determining the position and / or speed of a lifting device, according to claim 28, characterized in that after transmitting the transmitted ultra-broadband signal (18) by means of transmission (5) located at a first reference point, comprises reflecting said transmitted signal (18) in a reflector (26), located at a second reference point (6), being reflected as a reflected signal (19) towards a receiver located at the first reference point, said receiver being configured to detect said reflected signal (19).