FI93400C - A method and apparatus for reducing the annoyance of background noises carried to an elevator car - Google Patents

Description

93400

METHOD AND EQUIPMENT TO REDUCE THE INTERFERENCE OF BACKGROUND SOUNDS RELATED TO THE LIFT

The invention relates to a method according to the preamble of claim 1 and to an apparatus according to the preamble of claim 6 for reducing the annoyance of background sounds carried inside an elevator car.

In fast and high-quality elevators, driving comfort has become an increasingly important goal. One factor that affects driving comfort is the sounds heard in the elevator car. The elevator car carries 10 different sounds from the elevator equipment. Such sounds are e.g. the sounds of contact between the ropes and the rope pulleys, the running noises of the roller guides, the running noises of the hoisting motor and the noises caused by the air currents around the body. The intensity of the sounds carried to the car is often proportional to the instantaneous speed of the 15 car lifts. In this way, especially during the fastest travel of the elevator, the sounds are perceived as particularly annoying.

Efforts have been made to reduce the transmission of annoying noises to the car by soundproofing the car, but often adequate insulation cannot be achieved at a reasonable cost or at the expense of the usability of the car. Another common way to reduce distraction has been to try to mask background sounds with background music, but the disadvantage has been that background music is often perceived as distracting as well, especially if it does not suit the listener's taste in music or is saturated.

In order to attenuate background sounds, systems have been described, for example in International Application Publication WO 81/00638, in which the sound field prevailing in the state is attenuated by applying a wave of opposite phases to the sum wave measured from the sound field to the state, whereby the sum wave of the generated field decreases. Such a system is technically demanding and the practical implementation in the elevator car encounters problems. One of the reasons is that the elevator car as an acoustic transmission system does not have standard characteristics. For example, a situation where the doors are open 35 is different from a situation where the doors are completely closed.

2,93400 It is an object of the present invention to provide a new method and apparatus which reduces the annoyance of background sounds carried inside an elevator car. The method according to the invention is characterized by what is set forth in the characterizing part-5 of claim 1. The apparatus according to the invention is characterized by what is stated in the characterizing part of claim 6. Other preferred embodiments of the invention are characterized by what is stated in the other claims.

With the method and device according to the invention, due to the smaller volume variation, the elevator travel is perceived as more pleasant and even safer. The solution according to the invention is suitable for most elevators and can also be retrofitted, for example in connection with the modernization of an elevator.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a typical elevator speed curve, Figure 2 shows a corresponding volume curve, Figure 3 shows a volume curve in an elevator to which the invention has been applied, and Figure 4 shows an apparatus according to the invention.

Figure 1 shows a typical elevator speed curve. The vertical axis has the instantaneous speed and the horizontal axis the time. At time t0, the elevator car starts moving and is accelerated to full speed. Drive at full speed until braking begins before the 25th destination layer and finally stops at time tj. Figure 2 shows the volume variations corresponding to the elevator run. We start from a fairly quiet sound level of 35 dB (A). As you accelerate, the volume increases and at full speed, the volume is 60 to 30 dB (A). When decelerating at full speed, the volume curve follows the speed curve in a similar way. The volume of 35 dB (A) is usually perceived as quite quiet and the volume of 60 dB (A) is by no means abnormally high, but rather common in people's everyday living environments. The rather rapid change in volume is perceived as disturbing, especially during the ϊ 5 acceleration but also the deceleration phase. The sudden silence of the car when the doors close and thus attenuating the sounds carried from the elevator lobby (not shown in the figures) is also often disturbed. This sudden silence of the lobby sounds highlights the contrast perceived by the passenger between the volume of the elevator at stops 10 and the elevator at full speed. By reducing this contrast, annoyance can be substantially reduced.

Figure 3 shows a situation in which a background sound has been applied to the elevator car. Here, the volume range is reduced from -15 to about 6 dB (A), which is an almost imperceptible change under normal conditions. The passenger's hearing perception now supports the idea that the elevator runs quietly, although in absolute terms the volume may be even higher due to the added background noise.

20 The frequency content of the sound also affects the passenger experience. It is therefore advantageous to modify the frequency content of the background sound so that it blends easily with other sounds and is therefore difficult to distinguish. For example, a background noise resembling the background sound of an elevator lobby arising from ventilation, human movements, etc. is quite inconspicuous in the closing phase of the doors. Likewise, appropriately modified noise is not easily separated.

Figure 4 schematically shows an apparatus according to the invention. An audio transmitter 2 is placed in the elevator car 1. The multi-frequency signal from the signal-30 source 4 is filtered by a weighting filter 5 to obtain the desired frequency content, if necessary, and amplified by an amplifier 3. The gain of the amplifier is adjustable. The audio transmitter 2 is controlled via the amplifier 3. The gain as well as the way in which the frequency content is weighted can be controlled, if desired, either on the basis of elevator control information 4 93400 8, such as speed information or door status information, or directly from the elevator car or from outside the car, for example by microphone 6. Such a controller 7 can be separate or 5 part of the elevator control. The direction of the signals is indicated by arrows.

It will be apparent to those skilled in the art that the various embodiments of the invention are not limited to the examples set forth above, but may vary within the scope of the claims set forth below. In the simplest embodiment 10, a similar background noise is continuously applied to the elevator car, thus satisfying the achievable low volume level dynamics on a dB scale. In the more advanced version, the background sounds fed to the elevator car are controlled so that changes in the prevailing frequency distribution and volume of the sound are as slow as possible throughout the travel event, from when the passenger enters the elevator car from the lobby to when the passenger leaves the elevator at the destination.

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Claims (7)

A method for reducing the annoyance of background noises carried inside an elevator car, the method comprising transmitting a background sound to the elevator car (1) T, characterized in that the background noise transmitted to the elevator car (1) 5 is louder than the background noise caused by normal operation of the elevator. it is difficult to distinguish in terms of hearing perception. Method according to Claim 1, characterized in that the background sound transmitted to the elevator car (1) is white noise or modified from white noise. Method according to Claim 1, characterized in that a background sound which is externally transmitted to the elevator car in terms of its frequency content or a background sound resembling the background sound prevailing in the elevator lobby is transmitted to the elevator car (1). Method according to one of the preceding claims, characterized in that the volume and / or frequency content of the background sound transmitted to the elevator car (1) is controlled by a preset instruction corresponding to the current operating state of the elevator. Method according to one of the preceding claims, characterized in that the current in the elevator car (1) the background noise is detected and that, with the aid of the observation, an instruction is formed to control the volume and / or frequency content of the background sound to be transmitted to the elevator car (1). 5,934,000 Apparatus for reducing the annoyance of background sounds carried inside an elevator car, the apparatus comprising: a signal source (4) for transmitting background sound to an elevator car and an audio transmitter (2) placed in the elevator car (1), characterized in that the apparatus comprises a weighting filter (5) for signal transmitter (4); modifying the signal in terms of its frequency content to be difficult to distinguish from the point of view of hearing perception; and an amplifier (3) for adjusting the strength of the signal going to the modified audio transmitter (2). 6 93400 Apparatus according to claim 6, characterized in that the apparatus comprises a controller (7) for controlling the operation of the weighting filter (5) and / or the amplifier (3), and that the controller generates instructions for controlling the operation of the weighting filter (5) and / or amplifier 5 (3). is formed with the aid of an observation of the background noise prevailing in the elevator car (1) and / or on the basis of the elevator operating status information. «» «« «Π I: IM I lii h m at 7 93400