System and method for measuring punching position of stone chime

Abstract

The invention relates to a system and a method for measuring punching positions of stone chimes. The technical problem that the stone chime punching position cannot be correctly determined in the prior art is mainly solved. According to the technical scheme, the system for measuring the punching position of the stone chime comprises a stone chime bracket, stone chime excitation equipment, laser vibration measurement equipment and a computer system, the stone chime bracket is placed on the ground, and the detected imporous stone chime is hung on the stone chime bracket; the stone chime excitation equipment and the laser vibration measurement equipment are arranged on the front side and the back side of the detected non-porous stone chime and are connected with the computer system. The method comprises the following steps: 1, measuring the position of the mass center of the pore-free stone chime to be measured; 2, measuring a frequency response curve of the measured pore-free stone chime and drawing a vibration mode diagram; and step 3, determining the punching position of the detected pore-free stone chime by analyzing a frequency response curve and the vibration mode diagram and combining the mass center position obtained in the step 1.

Description

Technical Field

[0001] The invention belongs to the technical field of manufacturing, vibration measurement and analysis of percussion musical instruments, and in particular relates to a system and method for determining the drilling position of a stone chime. Background Art

[0002] The stone chime is an ancient percussion instrument that first appeared in the late Neolithic period at the Taosi site in Xiangfen, Shanxi Province, and has been passed down to this day. The appearance of the stone chime is as described in the "Records of Craftsmen in the Book of Zhou". Figure 1 As shown; the material used is hard stone with crisp sound. After being cut, polished, drilled and precisely tuned, it is arranged according to pitch, and the holes are connected in series with ropes and hung on a wooden frame to form a chime.

[0003] However, there is no clear documented record of how to determine the location of the holes on the stone chime. Modern craftsmen often use stone chime artifacts as templates to directly locate them, or according to convention, determine the location of the holes slightly below the highest point of the chord and slightly to the drum. None of the above methods have studied the scientific location of the holes. In fact, the location of the holes on the stone chime affects the stability and musicality of the stone chime when it is hung. When the stone chime is struck, the positional relationship between the hole and the center of mass of the stone chime and the mass distribution of the stone chime jointly affect the stability of the stone chime. An unstable stone chime cannot be struck continuously, affecting the performance; the vibration of the stone chime will also cause the vibration of the rope that suspends the stone chime. If the hole position is inappropriate, the vibration of the rope will affect the vibration frequency of the stone chime, thereby affecting the pronunciation effect of the stone chime.

[0004] The existing patent application number CN202310083577.2 discloses "A Porcelain Chime Stone and Its Manufacturing Method", which belongs to the technical field of porcelain musical instruments. One kind of porcelain chime stone and its manufacturing method includes a first chime stone body assembly and a second chime stone body assembly. The first chime stone body assembly and the second chime stone body assembly can be combined together to form a chime stone blank. The first chime stone body assembly and the second chime stone body assembly are both provided with grooves. The two grooves form a cavity in the chime stone blank. A sound hole is provided at the lower end of the drum portion of the chime stone blank, and the sound hole is connected to the cavity. The porcelain chime stone vibrates and sounds in the cavity formed by the combination of two porcelain shells, rather than a single chime stone body vibrating and making sound. Therefore, the porcelain chime stone and its manufacturing method do not provide a method for drilling holes in stone chimes. Therefore, it is urgent to develop a system and method for determining the drilling position of stone chimes. Summary of the invention

[0005] The purpose of the present invention is to solve the technical problem in the prior art that the position of the holes in a stone chime cannot be correctly determined, and to provide a system and method for determining the position of the holes in a stone chime.

[0006] To achieve the above object, the technical solution adopted by the present invention is: A system for measuring the drilling position of a stone chime, comprising a stone chime bracket, a stone chime excitation device, a laser vibration measuring device and a computer system; the stone chime bracket is placed on the ground, and a stone chime without a hole to be measured is suspended on the stone chime bracket by a rope; the stone chime excitation device is arranged on a side facing the stone chime without a hole to be measured and is connected to the computer system; the laser vibration measuring device is arranged on the other side of the stone chime without a hole to be measured and corresponds to the stone chime excitation device, and the laser vibration measuring device is connected to the computer system.

[0007] Furthermore, the stone chime bracket is a wooden structure and is covered with sound-absorbing sponge.

[0008] Furthermore, the stone chime excitation device is a loudspeaker, which continuously emits a sweep frequency signal of 20 Hz to 20 kHz for 1 second at a distance of 10 cm from the tested hole-free stone chime.

[0009] Furthermore, the laser vibration measurement equipment is a laser scanning probe, which is 1.5 to 3 meters away from the hole-free stone chime to be measured.

[0010] Furthermore, the computer system includes an excitation signal generator and Doppler frequency modulation information processing software; the computer system outputs a sweep frequency signal to the stone chime excitation device, and receives a signal transmitted back by a laser vibration measurement device, analyzes the vibration of the target by detecting the phase difference between the echo light beam and the local oscillation light beam, and generates a frequency response curve and a vibration modal diagram through calculation.

[0011] A method for using the system for determining the position of a stone chime hole comprises the following steps: The first step is to determine the centroid position of the measured stone chime without a hole: hang up the different end points of the measured stone chime without a hole one by one, use a plumb bob to make a vertical line, and the intersection of the vertical lines is the centroid of the measured stone chime without a hole; The second step is to measure the frequency response curve of the tested stone chime without holes and draw a vibration mode diagram: (1) The computer system controls the stone chime excitation device to send a sweep frequency signal to the stone chime without a hole to be tested, so that the stone chime without a hole to be tested generates vibration; (2) The computer system controls the laser vibration measuring device to emit a laser to irradiate the non-hole stone chime to be measured, and collects a vibration signal emitted by the non-hole stone chime to be measured; (3) After being processed by the computer system, a frequency response curve of the tested hole-free stone chime is obtained and a vibration modal diagram is drawn; The third step is to determine the drilling position of the tested hole-free stone chime by analyzing the frequency response curve and the vibration mode diagram obtained in the second step and combining them with the center of mass position obtained in the first step.

[0012] The beneficial effects of the present invention are: 1. The method for determining the drilling position of the stone chime of the present invention avoids the previous empirical positioning and drilling method, forms a scientific processing method, and gets rid of the previous vague empirical description and the manufacturing dilemma of only copying cultural relics.

[0013] 2. The present invention detects the frequency response curve and vibration mode of the stone chime, selects the intersection of the node lines of its main vibration frequency as the hanging hole point, and effectively weakens the coupling effect between the hanging rope and the main vibration frequency of the stone chime, thereby causing the vibration mode of the stone chime to be closer to the ideal plate vibration mode without boundary conditions, thereby improving the sound quality of the stone chime.

[0014] 3. The present invention determines the drilling position by combining the center of mass position of the stone chime, which effectively reduces the interference of the rope on the vibration of the stone chime and enhances the hanging stability of the stone chime, making it easier to strike continuously. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram of the stone chime recorded in "The Book of Zhou: Kaogongji"; Figure 2 It is a schematic diagram of a system for determining the position of a hole punched in a stone chime according to the present invention; Figure 3 It is a schematic diagram of the stone chime to be measured and the position of its center of mass; Figure 4 is an example diagram of the frequency response curve of the stone chime tested in the present invention; Figure 5 This is the 778 Hz vibration modal diagram of the stone chime tested in the present invention; Figure 6 This is the 2956 Hz vibration modal diagram of the stone chime tested in the present invention; Figure 7 It is a schematic diagram of the drilling positions of the stone chime to be tested according to the present invention; Figure 2 In the figure: 1—computer system; 2—laser vibration measuring device; 3—holeless stone chime to be measured; 4—stone chime vibration excitation device; 5—stone chime bracket. DETAILED DESCRIPTION

[0016] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0017] like Figure 2As shown, a system for determining the drilling position of a stone chime in this embodiment includes a stone chime bracket 5, a stone chime excitation device 4, a laser vibration measuring device 2 and a computer system 1; the stone chime bracket 5 is placed on the ground, and the stone chime 3 without holes to be measured is suspended on the stone chime bracket 5 by a rope; the stone chime excitation device 4 is arranged on a side facing the stone chime 3 without holes to be measured and is connected to the computer system 1; the laser vibration measuring device 2 is arranged on the other side of the stone chime 3 without holes to be measured and corresponds to the stone chime excitation device 4, and the laser vibration measuring device 2 is connected to the computer system 1. The stone chime bracket 5 is a wooden structure, and is covered with a sound-absorbing sponge.

[0018] The stone chime excitation device 4 is a loudspeaker, which continuously emits a sweep frequency signal of 20 Hz to 20 kHz for 1 second at a distance of 10 cm from the stone chime without a hole to be tested.

[0019] The laser vibration measuring device 2 is a laser scanning probe (Polytech PSV-500-H), which is 1.5 to 3 meters away from the hole-free stone chime to be measured.

[0020] The computer system 1 includes an excitation signal generator and Doppler frequency modulation information processing software; the computer system 1 outputs a sweep frequency signal to the stone chime excitation device 4, and receives a signal sent back by the laser vibration measurement device 2, analyzes the vibration of the target by detecting the phase difference between the echo light beam and the local oscillation light beam, and generates a frequency response curve and a vibration mode diagram through calculation.

[0021] A method for using the above-mentioned system for determining the position of a stone chime hole comprises the following steps: The first step is to determine the centroid position of the measured stone chime without a hole: hang up the different end points of the measured stone chime without a hole one by one, use a plumb bob to make a vertical line, and the intersection of the vertical lines is the centroid of the measured stone chime without a hole; The second step is to measure the frequency response curve of the tested stone chime without holes and draw a vibration mode diagram: (1) The computer system controls the stone chime excitation device to send a sweep frequency signal to the stone chime without a hole to be tested, so that the stone chime without a hole to be tested generates vibration; (2) The computer system controls the laser vibration measuring device to emit a laser to irradiate the non-hole stone chime to be measured, and collects a vibration signal emitted by the non-hole stone chime to be measured; (3) After being processed by the computer system, a frequency response curve of the tested hole-free stone chime is obtained and a vibration modal diagram is drawn; The third step is to determine the drilling position of the tested hole-free stone chime by analyzing the frequency response curve and the vibration mode diagram obtained in the second step and combining them with the center of mass position obtained in the first step.

[0022] Specifically: 1. According to the frequency response curve, select the two vibration frequencies with the largest amplitudes (from the sound measurement of stone chime cultural relics, there are usually two main vibration frequencies. Secondly, stone chimes are natural stones, and the probability of equal amplitudes is extremely small, so the situation of equal vibration amplitudes is not considered).

[0023] 2. Select the vibration modal diagrams corresponding to the two vibration frequencies with the largest amplitudes at the same time, and extract the node lines in the vibration modal diagrams (the node lines are the positions where the stone chimes are stationary when they vibrate at the corresponding frequencies, i.e. the boundaries of the different color areas in the vibration modal diagrams). Overlap the node lines extracted from the two diagrams, which will produce several intersection points.

[0024] 3. Then choose the intersection closest to the center of mass of the stone chime as the punching point. Because the stone chime is usually struck on the board surface on both sides of its edges, the closer the punching position is to the center of mass, the more stable the stone chime is.

[0025] The invention not only ensures that the main vibration frequency of the stone chime is not disturbed by the rope, but also enhances the stability of the stone chime when it is suspended, and especially provides guidance for drilling holes in special-shaped stone chimes. Specific embodiments

[0026] The present invention selects a sample example as follows: The stone chime sample is made of Lingbi stone produced in Lingbi County, Anhui Province, which is common on the market. It is made by local stonemasons and has not yet been drilled. The chime is 40 cm long, 15 cm high and 1.5 cm thick. Figure 3 shown.

[0027] 1. Steps to determine the center of mass of a stone chime: The stone chime is suspended at different ends, and a plumb bob is used to draw a vertical line. The intersection of the vertical lines is the centroid of the stone chime. Figure 3 The center of the mark is the measured center of mass of the stone chime being measured.

[0028] 2. Measure the frequency response curve of the stone chime and draw the vibration mode diagram: Using the measuring system of the present invention, the laser vibration measuring device is placed 1.5 meters in front of the stone chime to be measured, and the stone chime excitation device is placed 10 centimeters behind the stone chime.

[0029] The experimental steps are the same as those in the previous specific implementation, and the following experimental results are obtained: Get as Figure 4 The example graph of the stone chime frequency response curve shown in Figure 5 and Figure 6 The vibration mode diagrams of 778 Hz and 2956 Hz are shown.

[0030] By observing the frequency response curve of the stone chime in the experiment of the present invention, Figure 4As shown, the two vibration frequencies with the largest amplitudes, 778 Hz and 2956 Hz, are selected, and the vibration modal diagrams corresponding to 778 Hz and 2956 Hz are selected, as shown in Figure 5 and Figure 6 as shown; and extract the node lines.

[0031] Depend on Figure 5 The node line extracted from is the boundary line of the two color areas, that is, the boundary line between ② and ①, and between ② and ③. Figure 5 The two black lines are shown.

[0032] The node line extracted from Figure (6) is also the boundary line between the two color areas, that is, the boundary line between No. ④ and No. ①, No. ④ and No. ②, and No. ④ and No. ③. Figure 6 The three black curves are shown.

[0033] by Figure 6 Based on Figure 5 The two node lines extracted from are added to obtain Figure 7 There are four intersection points ①, ②, ③, and ④ shown, and ⑤ is the center of mass position.

[0034] Point ②, which is closest to the center of mass, is selected as the drilling position of the stone chime to be measured in this embodiment.

[0035] The invention is applicable to the vast majority of stone chime styles currently available on the market, and is also applicable to the measurement of special-shaped thin soundboards, and its principles and measurement methods are universal.

Claims

1. A system for determining the position of a hole in a stone chime, characterized in that: It includes a stone chime bracket, a stone chime vibration device, a laser vibration measuring device and a computer system; the stone chime bracket is placed on the ground, and the stone chime without holes to be measured is suspended on the stone chime bracket through a rope-like object; the stone chime vibration device is arranged on a side facing the stone chime without holes to be measured and is connected to the computer system; the laser vibration measuring device is arranged on the other side of the stone chime without holes to be measured and corresponds to the stone chime vibration device, and the laser vibration measuring device is connected to the computer system.

2. A system for determining the position of a stone chime hole according to claim 1, characterized in that: The stone chime bracket is a wooden structure and is covered with a sound-absorbing sponge.

3. The system for determining the position of a stone chime hole according to claim 1, characterized in that: The stone chime excitation device is a loudspeaker, which continuously emits a sweep frequency signal of 20 Hz to 20 kHz for 1 second at a distance of 10 cm from the tested stone chime without holes.

4. The system for determining the position of a stone chime hole according to claim 1, characterized in that: The laser vibration measuring device is a laser scanning probe, which is 1.5 to 3 meters away from the hole-free stone chime to be measured.

5. The system for determining the position of a stone chime hole according to claim 1, characterized in that: The computer system includes an excitation signal generator and Doppler frequency modulation information processing software; the computer system outputs a sweep frequency signal to the stone chime excitation device and receives a signal sent back by a laser vibration measurement device, analyzes the vibration of the target by detecting the phase difference between the echo light beam and the local oscillator light beam, and generates a frequency response curve and a vibration mode diagram through calculation.

6. A method for using the system for determining the position of a stone chime hole according to claim 1, characterized in that: The steps include: The first step is to determine the centroid position of the measured stone chime without a hole: hang up the different end points of the measured stone chime without a hole one by one, use a plumb bob to make a vertical line, and the intersection of the vertical lines is the centroid of the measured stone chime without a hole; The second step is to measure the frequency response curve of the tested stone chime without holes and draw a vibration mode diagram: (1) The computer system controls the stone chime excitation device to send a sweep frequency signal to the stone chime without a hole to be tested, so that the stone chime without a hole to be tested generates vibration; (2) The computer system controls the laser vibration measuring device to emit a laser to irradiate the non-hole stone chime to be measured, and collects a vibration signal emitted by the non-hole stone chime to be measured; (3) After being processed by the computer system, a frequency response curve of the tested hole-free stone chime is obtained and a vibration modal diagram is drawn; The third step is to determine the drilling position of the tested hole-free stone chime by analyzing the frequency response curve and the vibration mode diagram obtained in the second step and combining them with the center of mass position obtained in the first step.

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