SE440399B - Device for recording events, such as magnitude and lapse - Google Patents

Abstract

The invention refers to a device for recording events, such as magnitude and lapse. A transmitter unit (1) senses the above named events. A signal processing unit (2) receives a transmitted signal from the transmitter unit. A writing unit records (30, 31) events depending on the given electric output signal. The writer unit presents a writing surface (24) on which a movable writing device carries out point by point recording at predetermined time intervals. The units control the writing device so that its writing tool, after a reading to an event in question indicates the event (29/32) by first carrying out a slow return motion while carrying out the point by point recording (30, 31) on the writing surface (24) under a time interval and with a predetermined distance between the records. After this the writing device carries out a faster return motion to its starting position while carrying out point by point recording with a predetermined considerably greater distance between the records. Alternatively, the writing device does not conduct any recording during the faster return motion.<IMAGE>

Description

The invention will be described in more detail below with an exemplary embodiment with reference to the accompanying drawings, in which Fig. 1 shows a block diagram of the present invention in an exemplary embodiment, Fig. 2 shows an example of registrations obtained by means of the device according to the invention, Figs. 3 and 4 schematically show the waveform of two signals appearing in the device according to the invention.

As an example of an application of the invention, a device has been chosen for continuous monitoring of vibrations, for example caused by blasting, piling, demolition work and heavy traffic. More specifically, for example, the oscillation speed or amplitude of existing vibrations is measured and recorded.

Such measurements are performed, for example, in adjacent buildings to find out if the vibrations exceed permissible values in the event of damage to the property.

For this purpose, the device according to the invention is mainly built up of a sensor unit 1, a signal processing unit 2 and a writing unit 3. The sensor unit is thus intended to sense the measured quantity to be measured, as in the example shown the oscillation speed, for example in mm / s. The sensor unit 1 can be of a construction known per se and in the current application it can thus be arranged to sense vibrations. For example, the sensor unit 1 can be built up of a movably suspended coil, which is arranged to perform a relative movement in relation to the other parts of the sensor, - for example a magnetic core.

The signal processing unit 2 is connected with its input 4 to the sensor unit 1 and with its output 5 connected to the writing unit 3. The signal processing unit 2 is next to its input provided with an amplifier 6 for amplifying a sensor signal emitted from the sensor unit 1 and a low-pass filter 7 connected to the amplifier. for interference limitation. The low-pass filter in the example shown has a cut-off frequency of 1000 Hz. After the low-pass filter 7, a rectifier 8 is connected.

The rectifier 8 is a full wave rectifier; which transmits the negative part of the sensor signal to positive signals. Connected to the rectifier 8 is a peak value detector 9, which is arranged to sense the peak value of the sensor signal and to output to the signal conversion unit 2 output 5, i.e. to the printer 3, an output signal which determines the writing unit 3's output. Furthermore, the signal conversion unit 2 includes a comparator 10, which is arranged to compare the signal at the first input 11 of the peak value detector with the signal at its output 12. A timer unit 14 is connected to the output 13 of the comparator, which has a first input 15 and a second input 16 and a output 17, which is connected to a second input 18 of the peak value detector 9. The signal conversion unit 2 further comprises a pulse sensor 19, which is arranged to sense the output signal 5 of the signal conversion unit and to emit a pulse when the output signal has such a value that the write unit 3 rash fits- f '8004582-6 rar a certain part of full rash, in the tfiszlde ex fl- mplf-t 9' lu of full rash. Connected to the encoder 19 is a switch unit 20, which in the example shown consists of a stable pin, which has an R-input and an S-input and a Q-output. With the Q output, the flip-flop 20 is connected to the second input 16 of the timer unit 14 and to a third input 21 to the peak value detector 9. Furthermore, an activating unit 22 is included, which is connected to the flip-flop 20 R input and a fourth input 23 at peak value The detector 9. The activating unit 22 is designed to give an impulse to these inputs in certain situations. In the example shown, these situations can be constituted by switching on or disconnecting the device according to the invention, which is effected by means of a switch (not shown), disconnected from the sensor unit 1, alternatively switching between different measuring ranges for the device, which can also be effected by means of a switch, for example one and saznina switch as the on / off switch. Switching between different measuring ranges is a measure known per se to increase the area of use of the device by varying its sensitivity. For example, in a position for the switch you can obtain a measuring range 0-100 mm / s and in another position you get a measuring range 0-9 mm / s.

The writing unit 3 consists of a so-called dot printer, which is arranged to perform a number of dot-wise registrations on a writing surface 24, which is shown with an example in Fig. 2. An example of such a printer is Rustrak model 288. The writing surface 24 in a dot-com printer consists of a specially prepared paper or the like, on which a mark is obtained at a mechanical pressure on the writing surface. The paper is made up of an upper. for example, light layer, which has a plurality of scale lines, and an underlying layer, for example dark layer, which forms a contrast to the upper layer. The upper layer is in fact easily breakable. in the case of mechanical contact, whereby the darker layer thus appears in the form of, for example, dots. More specifically, the dots form short lines, which facilitates reading for the writing unit. The dot-com printer 3 further has a writing means, which upon registration is brought down towards the writing surface 24 and provides a dot-by-dot recording. The writing means is arranged to perform a movement over the writing surface 24, in the example shown in the transverse direction of the writing surface, i.e. across the direction of the arrow 25. Namely, the writing means consists of the pointer of a galvanometer input to the 1 'point printer, which is connected to the output 5 of the signal conversion unit 2 and is arranged to sense the current of the output signal at the output 5. The galvanometer in the above-mentioned model has a measuring range of 0-1 mA and a resistance of 100 ohms. Furthermore, the dot-com printer includes a drive motor, which is arranged to, with a low, constant prefill-f-lšixiicl llas-ligfliz-t irmnnlala written-ln 'f-'li clc-.ss line direction, i.e. in that with the arrow 2 : 3 denoted the direction. Through this frammauiiiig; a time scale is obtained which is divided by means of transverse scale bars 26. On this time scale, times are indicated, which are entered in the left Ita-nt of the writing surface. ï-lf-d 27 denote perforations which are used for the advancement of the writing surface 18 by means of a gear which engages in the perforations and is driven by the drive motor. The drive motor in the point printer is suitably connected to the activation unit 22 of the signal processing unit 2, so that when the device is switched off, the drive motor starts and the writing surface 18 moves in its longitudinal direction. The movable arm of the writing means is so located that it performs its deflection movement substantially transversely to the feed direction of the paper in the form of a pivoting movement. The dot-com printer is controlled, as will be described in more detail below, so that the writing means performs a rapid turning motion from an initial position, for example in the middle of line 28, which represents zero position to a turning position 29, in which the printer with its writing means begins to perform a slow movement during point-by-point recordings. 30. The writing means thus performs a raising and lowering movement in a manner known per se by means of, for example, a drop bar. The raising and lowering movement is time-controlled, so that the writing means is lowered towards the writing surface at predetermined time intervals, for example 2 seconds. However, the dot-com writer does not make point-by-point recordings at the same intervals throughout his return movement to the initial position 28, which will be explained in more detail below. It is thus a wish to obtain a relatively small distance between such registrations, the value of which is to be read, ie between points 30, so that the greatest possible measurement accuracy is obtained at the turning point 29. At the same time it is desirable that each registration occasion, i.e. each rash and recurrence, occurs in the shortest possible time, which are thus two conflicting wishes, which are solved by means of the present invention in a manner explained below.

When the current measured quantity is sensed by the sensor unit 1, ie in the case described vibrations, transmitted for example by the sensor unit abutting a surface with a surface, for example a wall in a property, the sensor unit emits a sensor signal to the signal processing unit 2 input 4 In the present case, the sensor signal consists of an electrical voltage, which in the case of vibration shocks varies mainly as a sinusoidal damped oscillation. The sensor signal is amplified in the amplifier 6 and is rectified in full wave in the rectifier 7, whereby a modified sensor signal is obtained which is schematically shown with an example in Fig. 3.

This signal is fed to the first input 11 of the peak value detector 9. From the peak value detector an output signal is emitted at its output 12, which also constitutes an output signal from the signal processing unit 2, which is emitted at its output 5. The output signal from the peak value detector 5 forms a signal with solid line in Fig. 4. The maximum value of the voltage for this signal is represented by the peak value of the sensor signal according to Fig. 3. The output signal according to Fig. 4 falls along a straight line for a first shorter time, for example 9.5 seconds, after which the signal falls quickly and reaches zero value after, for example, a total of 20 se- f * in 8004582-6 customers. Ile-Ita iistacikornrnc-s by means mainly kf-xnpzzratcwrn l () (mh tíxntrfnhetzn 14, which work with digital technology, why on their outputs 13, l? Appear two different voltage levels, high and low voltage level, normally presence of voltage with for example 5 In the coin comparator 10, the output signal from the peak value detector 9 is compared with the sensor signal filter 4, and when the sensor signal exceeds the output signal from the peak value test detector, the voltage state on the comparator output 13 changes, which becomes, for example, its input 15, whereby the timer unit is activated and its output 17 becomes high, at the same time as the timer unit starts counting, i.e. measuring time, during a predetermined time interval.

This is, for example, set to 9.5 seconds. Almost instantaneously when the sensor signal reaches its highest value, the peak value, the output signal from the signal processing unit 2 rises to a maximum value, which represents said peak value, after which the output signal falls slowly during said time interval. Thereafter, the voltage state at the output unit 17 of the timer unit changes from, for example, high to low voltage state. This change is thus sensed by the peak value detector 9 at its second input 18, whereby its output signal at the output 12 thus goes down to zero after this predetermined time. The fast falling sequence of the output signal thus reaches zero value after a second predetermined time interval, for example 20 seconds. As soon as the magnitude of the output signal from the peak value detector 9 falls below the sensor signal, the comparator 9 changes the voltage state at its output, which then becomes low, for example, whereby the timer unit 10 is reset and is ready for a new time measurement.

The decrease of the output signal with time is effected, for example, by discharging a capacitor, the discharge time determining the slope of the output signal. In the example shown, the discharge time up to 9.5 s is fixed at 200 s, which is indicated by the dashed, extended line in Fig. 4. At 9.5 s, the voltage change at the second input 18 of the peak value detector 9 results in a considerably faster discharge. , which is achieved, for example, by making a transistor connected in parallel with said capacitor made conductive. In this case, the second input 18 of the peak value detector 9 is formed by the base of this transistor. In addition to certain control inputs and the said capacitor, which are also discussed below, the peak value detector 9 is mainly made up of Lex. two operational amplifiers, which are connected in series between the detector's input 11 and output 12.

The output signal from the signal conversion unit 2 is thus arranged to drive the galvanometer in the dot-screen printer 3, which thus performs a reading which is proportional to this output signal. As mentioned above, the writing device performs a knock-out movement to its turning point 29, after which it begins to perform point-by-point registrations, the mutual time intervals of which are, for example, 2 seconds, which during the first time period gives a point density of, for example, 4 points / nun. This recording movement is thus relatively slow, since it is controlled by the output signal slowly decreasing after reaching the maximum speed, but changes to a faster reset movement after the time period determined by the timer unit 10, which in the current example is selected to 9.5 seconds. As a result, only a few frequent registrations are performed first, approximately 4-5 registrations. These registrations are completely sufficient to make the registration result easily readable, since it is only the registration at the turning point that is of interest from a reading point of view. During the return movement after 9.5 seconds, ie up to 20 seconds according to the example shown, registrations 31 also take place, but with a point density of approximately 0.05 points / mm, which registrations facilitate the reading by detecting the impact time more easily on the time scale. . If the peak value detector 5 were to emit an output signal without affecting the timer unit 10, it would emit an output signal determined by the above-mentioned discharge time with a continuously falling line, which thus constitutes the dashed line shown in Fig. 4, which falls to zero. during a predetermined time interval of, for example, 200 seconds.

During this time, the writing means would thus move very slowly during its entire return movement all the way to the zero position 28 and make point-by-point registrations, which, however, would have no information value. However, during this time period no further measurement could be undertaken, but the device is blocked for recording vibrations with a lower value during this time, which is thus not the case with the device present invention.

The function of the device and the registrations obtained when registering measurement results have been described above. However, the device according to the invention is so arranged that the writing unit 3 also registers other events, namely the switching on and disconnection of the device, the disconnection of the sensor, alternatively cable breakage between the sensor and the signal conversion unit, and switching between different measuring ranges. This is achieved by means of some of the above-mentioned units in the signal processing unit 2, namely the pulse sensor 19, the flip-flop 20 and the activation unit 22, which control both the timer unit 14 and the peak value detector 9 in such a way as to obtain recordings which detect the above-mentioned When the device is switched on or if any of the other situations arise, the activation unit 22 emits a pulse at its output. This pulse is input to the fourth input 23 of the peak value detector and thereby simulates a sensor signal which corresponds to a full response at the writing unit 3, i.e. controls the peak value detector 9 so that it is caused to output an output signal at its output 12 with such a maximum value. that a full reading is obtained at the writing unit. This pulse from the activating unit 2 is simultaneously fed to the bistable flip-flop 20 at its R-input, the flip-flop being set so that its output Q becomes low. The output signal from -1 8004582-6 your l-istabila vipyan is taken to tfipjivärdesdetf-kterixs 9 trulje irxgišng 21 and controls this so that the signal emitted by the peak value detector falls with a faster course than is the case when registering a measurement event. This control of the peak value detector can be achieved in basically the same way as when recording a measurement result, for example by also connecting the third input 21 to the base of a transistor, which is thus not the same transistor as in the case of a transistor. the input 18, whereby the transistor can be switched to two different conduction states to provide a predetermined discharge of the above-mentioned capacitor and thereby obtain the desired slope of the output signal from the peak value detector. The appearance of the registrations at the mentioned events, which do not constitute measurement occasions, is shown in Fig. 2. The writing body has, for example, at 07.00 made a full reading and performed a registration at its turning point 32. after which registrations were performed at intervals of, for example, 2 seconds, which due to the faster decay of the output signal resulted in a smaller point density than on a measurement occasion. Thus, in the example shown, the point density is, for example, about 0.7 points / mm, whereby five recordings 33 with this point density are performed. This point density is obtained at a constant fall rate of the output signal, corresponding to a fall time from full range to zero of 80 s. However, this point density does not occur during a predetermined time interval as in a measurement occasion. Since in practice it has proved difficult to simulate a signal for full burst so that the writing gear faces exactly at the shell line 32, it has instead been chosen to voltage control the registration for full burst. This is accomplished by the encoder 19 in the following manner. Before the voltage of the output signal has fallen to a value corresponding to, for example, 9/10 of full range, the Q output of the flip-flop is thus low, which means that the output of the timer unit is kept high. When 9/10 of full range is passed, an impulse is emitted from the encoder, which makes the flip-flop Q output high and controls the peak value detector 9 via its input 21 so that the desired discharge time is obtained, i.e. so that the output signal from the peak value detector zero value, which is reached after, for example, 20 s. In this case, the said registrations 31 are thus obtained with, for example, a point density of 0.05 points / mm. At the passage of 9/10 of full range, the timer unit 14 is reset at its input 16 by the output signal from the flip-flop, whereby the timer unit is again receptive to activation and time measurement when state change occurs at the input 15.

In the manner described above, different events can thus be read on the diagram strip 24 for a certain period of time. Vid det i fíg. 2 can thus, for example, be read as follows: Kl. 07.00 the device is connected with the sensor unit 1 connected.

Kl. 07.15 registration of a measurement occasion, measured quantity 70 mm / s at connected measuring range 0-100 min / s. 8004582-6 8 Kl. 07.30 givzirenhctt-n disconnected: alternatively kahf-ll »rolt Kl. 08.30 change of: target range to 0-9 mm / s.

Kl. 08.45 registration of a measurement result 3.5 mm / s.

Kl. 09.00 the sensor disconnected or broken cable.

The strong lines at the zero line 28 are obtained by the writing means through the pointwise recordings which are constantly performed during the advance of the diagram.

As can be seen, the zero line is moved when changing the measuring range to give an easy-to-read scale division. However, this is known per se and does not constitute an object of the present invention, so this function is not described in more detail in this example.

The invention is not limited to the embodiments described above and shown in the drawings, but can be varied within the scope of the following patent claims. For example, the measured quantities of the processes may be of a completely different kind than in the case described above. For example, the sensor may be arranged to sense an electrical quantity instead of a physical quantity. For example, the writing unit 3 can be of the multi-channel type, for example two-channel printers, whereby some of the above-mentioned point intervals can be halved. The writing movement of the writing means after the time interval with relatively more frequent registrations can be varied to a very high degree and in the extreme case the point gap can amount to or exceed full scale, thus no registrations occur after this time interval of, for example, 9.5 seconds. For the sake of clarity, the registrations for measurement occasions have been shown at larger intervals than those stated above, and in practice this is the case. These registrations can in some cases be so dense that they are perceived by the eye as a rectangular surface, which, however, is within the scope of the invention. Eat

Claims (6)

8004582-6 PATENT REQUIREMENTS A device for recording events, such as quantities and processes, comprising a sensor unit (1), which is arranged to detect at least some of said events, a signal processing unit (2), which is arranged to receive a sensor signal from the transducer unit, and a writing unit (3) arranged to effect registrations (30, 31) in response to an electrical output signal emitted from the signal processing unit and having a writing surface (24) on which a movable writing means is arranged to perform point-by-point recordings at predetermined time intervals, characterized in that the device includes units for controlling the writing unit (3) so that its writing means after a turning movement to a relevant event turning point (29/32) first performs a long same return movement while performing the pointwise recordings (30, 31) on the writing surface (24) for a time interval and with a predetermined first distance between the recordings and thereafter a relatively faster return movement to its initial position during the execution of point-by-point registrations with a predetermined second considerably greater distance between the registrations or without performing registrations. Device according to claim 1, characterized in that the device is arranged to register a first type of event, constituting a measured quantity, for which the position of the turning point (29), i.e. the magnitude of the impact movement of the writing means, represents the measured quantity and for which said first distance between the registrations constitutes a relatively small distance, and that the device is arranged to further register a second type of event, for which the position of the turning point (32) is predetermined and for which said first distance between registration garments constitutes a larger distance the distance for the first type of event. Device according to claim 2, characterized in that the turning point (32) for said second type of event corresponds to the full range of the writing means. Device according to claim 2 or 3, characterized in that said second type of event includes switching on of the signaling device, disconnection of the sensor unit (1) from the signaling device (2), disconnection between different mitochondria or such. 8004582-6 1o Device according to one of the preceding patent claims, characterized in that the signal processing unit comprises a peak value detector (9) arranged to sense the absolute peak value of the sensor signal for its current and to output said output signal, the maximum value of which represents said peak value. with the time after a predetermined process, partly a comparator (10), arranged to compare the sensor signal with the output signal and to emit an output signal, when the sensor signal exceeds the output signal of the peak value detector and partly a timer unit (14) arranged to be activated by the comparator output signal and in said first type of events, measuring said predetermined time interval for said slow return movement and then emitting an output signal to the peak value detector to cause it to decrease to zero after a certain slower deceleration with a considerably faster course. Device according to claim 5, characterized in that the signal processing unit (2) includes an activation unit (22), one which is arranged to output such an output signal to said peak value detector (9), that its output value maximum value corresponds to full scale and an impulse sensor (19) which is arranged to emit an impulse when the writing means passes a predetermined part, for example 9/10 of full scale, whereby the peak value detector is controlled so that its output decreases with a slightly faster course than in said first type of events before said part of full range has passed, and then proceeds to a further faster course to achieve said registration of with the considerably greater mutual distance or to return to the initial position without registrations .