A method and system for measuring sound pressure level of sound waves

Abstract

The application discloses a kind of method and system for measuring sound pressure level of sound wave, belong to sound wave measurement technical field.The application includes: at the position of sound wave measurement point, by the microphone based on capacitive diaphragm to the sound wave is measured, to store the mixed electric signal including first interference electric signal and sound wave pressure signal, while, by the microphone based on interference receiving component to the sound wave is measured, to store second interference electric signal;Receive mixed electric signal and second interference electric signal, based on the interference signal cancellation algorithm of pre-set to mixed electric signal and second interference electric signal are preprocessed, to obtain the interference frequency point component value of sound wave and sound wave frequency point component value;According to the sound wave frequency point component value, determine the sound pressure level of sound wave.The application receives sound wave using interference receiving component, can determine the interference amount received by capacitive diaphragm, can eliminate the interference of this part in acoustics measurement by pre-set algorithm to signal processing.

Description

Technical Field

[0001] This invention relates to the field of acoustic wave measurement technology, and more specifically, to a method and system for measuring acoustic wave sound pressure levels. Background Technology

[0002] Electrical equipment radiates audible sound into the air during operation, and its acoustic measurement is receiving increasing attention, playing a crucial role in power grid environmental protection and intelligent operation and maintenance. However, because electrical equipment typically operates in a low-frequency, strong electromagnetic environment, its acoustic measurements face electromagnetic interference problems. The signals measured by the microphone are mixed with acoustic signals and electromagnetic interference signals, making it difficult to obtain the true acoustic quantities of the equipment.

[0003] To address the aforementioned technical problems, existing technologies typically employ metal shielding covers or shielding rings to cover or enclose the electronic circuitry, such as preamplifiers, inside the microphone to resolve electromagnetic interference issues in acoustic measurements of power equipment. While this method is simple in principle and easy to implement, the microphone itself requires the diaphragm to be exposed to receive sound wave vibrations, thus electromagnetic shielding cannot completely cover the microphone. Consequently, existing solutions cannot shield against interference signals coupled to the microphone diaphragm. Summary of the Invention

[0004] To address the above problems, this invention proposes a method for measuring sound pressure level, the method comprising:

[0005] At the sound wave measurement point, the sound wave is measured by a microphone based on a capacitor diaphragm to store a mixed electrical signal including a first interference electrical signal and a sound wave pressure signal. At the same time, the sound wave is measured by a microphone based on an interference receiving component to store a second interference electrical signal.

[0006] The system receives a mixed electrical signal and a second interference electrical signal, and preprocesses the mixed electrical signal and the second interference electrical signal based on a preset interference signal cancellation algorithm to obtain the interference frequency component value and the sound wave frequency component value.

[0007] The sound pressure level of the sound wave is determined based on the frequency component values ​​of the sound wave.

[0008] Optional interference receiving components include: adjustable microcapacitors, insulating supports, housings, and connection terminals;

[0009] The insulating support is a disc with a central opening. The two plates of the adjustable microcapacitor are connected to the connecting terminal through the central opening of the insulating support via connecting wires. The connecting terminal is connected to the preamplifier of the microphone. The adjustable microcapacitor, the insulating support, and the connecting terminal are all housed in the outer casing.

[0010] The adjustable microcapacitor is used to receive interference electrical signals and transmit them to the connection terminal through the connection line. The interference electrical signals are then transmitted to the preamplifier of the microphone through the connection terminal. The insulating support is used to support the adjustable microcapacitor.

[0011] Optionally, the adjustable microcapacitor has a capacitance range of 50pF to 80pF.

[0012] Optionally, the mixed electrical signal and the second interference electrical signal are preprocessed based on a preset interference signal cancellation algorithm to obtain the interference frequency component value and the sound wave frequency component value, including:

[0013] Based on the second interference electrical signal, the spectrum domain of the second interference electrical signal is obtained, the components of the second interference electrical signal at a preset frequency point in the spectrum domain are extracted, and the interference frequency component value of the sound wave is determined based on the components of the second interference electrical signal.

[0014] Based on the mixed electrical signal, the spectrum domain of the mixed electrical signal is obtained, the components of the mixed electrical signal at preset frequency points in the spectrum domain are extracted, and the sound wave frequency component value is determined based on the components of the mixed electrical signal.

[0015] Optionally, the preset frequency point is located in the range of 50Hz to 2500Hz, and the preset frequency point is an integer multiple of 50Hz.

[0016] Alternatively, the formula for calculating the sound pressure level is as follows:

[0017]

[0018] Wherein, SPL is the sound pressure level of the sound wave. For the i-th frequency point f i The sound pressure level at the frequency p ref is the acoustic reference sound pressure level, and i is the frequency label.

[0019] Furthermore, the present invention also proposes a system for measuring sound pressure levels, comprising:

[0020] The measurement unit is used to control a microphone based on a capacitor diaphragm to measure sound waves at the sound wave measurement point to store a mixed electrical signal including a first interference electrical signal and a sound wave pressure signal. At the same time, it controls a microphone based on an interference receiving component to measure sound waves to store a second interference electrical signal.

[0021] The first calculation unit is used to receive the mixed electrical signal and the second interference electrical signal, and preprocess the mixed electrical signal and the second interference electrical signal based on a preset interference signal cancellation algorithm to obtain the interference frequency component value and the sound wave frequency component value.

[0022] The second calculation unit is used to determine the sound pressure level of the sound wave based on the frequency component values ​​of the sound wave.

[0023] Optional interference receiving components include: adjustable microcapacitors, insulating supports, housings, and connection terminals;

[0024] The insulating support is a disc with a central opening. The two plates of the adjustable microcapacitor are connected to the connecting terminal through the central opening of the insulating support via connecting wires. The connecting terminal is connected to the preamplifier of the microphone. The adjustable microcapacitor, the insulating support, and the connecting terminal are all housed in the outer casing.

[0025] The adjustable microcapacitor is used to receive interference electrical signals and transmit them to the connection terminal through the connection line. The interference electrical signals are then transmitted to the preamplifier of the microphone through the connection terminal. The insulating support is used to support the adjustable microcapacitor.

[0026] Optionally, the adjustable microcapacitor has a capacitance range of 50pF to 80pF.

[0027] Optionally, the first calculation unit preprocesses the mixed electrical signal and the second interference electrical signal based on a preset interference signal cancellation algorithm to obtain the interference frequency component value and the sound wave frequency component value, including:

[0028] Based on the second interference electrical signal, the spectrum domain of the second interference electrical signal is obtained, the components of the second interference electrical signal at a preset frequency point in the spectrum domain are extracted, and the interference frequency component value of the sound wave is determined based on the components of the second interference electrical signal.

[0029] Based on the mixed electrical signal, the spectrum domain of the mixed electrical signal is obtained, the components of the mixed electrical signal at preset frequency points in the spectrum domain are extracted, and the sound wave frequency component value is determined based on the components of the mixed electrical signal.

[0030] Optionally, the preset frequency point is located in the range of 50Hz to 2500Hz, and the preset frequency point is an integer multiple of 50Hz.

[0031] Optionally, the calculation formula for the sound pressure level of the second calculation unit is as follows:

[0032]

[0033] Where SPL is the sound pressure level of the sound wave. For the i-th frequency point f i The sound pressure level at the frequency p ref is the acoustic reference sound pressure level, and i is the frequency label.

[0034] In another aspect, the present invention also provides a computing device, comprising: one or more processors;

[0035] A processor is used to execute one or more programs;

[0036] When the one or more programs are executed by the one or more processors, the method described above is implemented.

[0037] In another aspect, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the method described above.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] This invention provides a method for measuring the sound pressure level of a sound wave, comprising: selecting a sound wave measurement point; measuring the sound wave at the measurement point using a microphone based on a capacitor diaphragm to store a mixed electrical signal including a first interference electrical signal and a sound wave pressure signal; simultaneously measuring the sound wave using a microphone based on an interference receiving component to store a second interference electrical signal; receiving the mixed electrical signal and the second interference electrical signal; preprocessing the mixed electrical signal and the second interference electrical signal based on a preset interference signal cancellation algorithm to obtain the interference frequency component value and the sound wave frequency component value; and determining the sound pressure level of the sound wave based on the sound wave frequency component value. This invention uses an interference receiving component to receive the sound wave, which can determine the amount of interference received by the capacitor diaphragm, and by processing the signal using a preset algorithm, can eliminate this interference in the acoustic measurement. Attached Figure Description

[0040] Figure 1 This is a flowchart of the method of the present invention;

[0041] Figure 2 This is a structural diagram of the interference receiving component in the method of the present invention;

[0042] Figure 3 This is a structural diagram of the system of the present invention. Detailed Implementation

[0043] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0044] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0045] Example 1:

[0046] The microphone used in acoustic measurement consists of a capacitor diaphragm, a preamplifier, and related circuitry. The capacitor diaphragm converts the sound pressure in the air into a primary electrical signal. This primary electrical signal is amplified by the preamplifier and then transmitted via cable to a digital acquisition system to obtain a digital signal associated with the sound pressure. After processing by the calculation and analysis system, this digital signal displays the acoustic value corresponding to the original sound pressure.

[0047] A capacitive diaphragm is essentially a capacitor element; it must be exposed to air to sense sound waves. However, electromagnetic interference can also couple in through the diaphragm, forming interfering electrical signals. These interfering signals mix with the primary electrical signal and are transmitted to subsequent processing stages, causing the final displayed acoustic value to differ from the sound pressure level. Therefore, this invention proposes a method for measuring sound pressure level, such as... Figure 1 As shown, it includes:

[0048] Step 1: At the sound wave measurement point, the sound wave is measured by a microphone based on a capacitor diaphragm to store a mixed electrical signal including a first interference electrical signal and a sound wave pressure signal. At the same time, the sound wave is measured by a microphone based on an interference receiving component to store a second interference electrical signal.

[0049] Step 2: Receive the mixed electrical signal and the second interference electrical signal, and preprocess the mixed electrical signal and the second interference electrical signal based on the preset interference signal cancellation algorithm to obtain the interference frequency component value and the sound wave frequency component value.

[0050] Step 1: Determine the sound pressure level of the sound wave based on the frequency component values ​​of the sound wave.

[0051] Among them, the interference receiving component, such as Figure 2 As shown, it includes: an adjustable microcapacitor, an insulating support, a housing, and connecting terminals;

[0052] The insulating support is a disc with a central opening. The two plates of the adjustable microcapacitor are connected to the connecting terminal through the central opening of the insulating support via connecting wires. The connecting terminal is connected to the preamplifier of the microphone. The adjustable microcapacitor, the insulating support, and the connecting terminal are all housed in the outer casing.

[0053] The adjustable microcapacitor is used to receive interference electrical signals and transmit them to the connection terminal through the connection line. The interference electrical signals are then transmitted to the preamplifier of the microphone through the connection terminal. The insulating support is used to support the adjustable microcapacitor.

[0054] The adjustable microcapacitor has a capacitance range of 50pF to 80pF.

[0055] The preprocessing of the mixed electrical signal and the second interference electrical signal based on a preset interference signal cancellation algorithm is used to obtain the interference frequency component value and the sound wave frequency component value, including:

[0056] Based on the second interference electrical signal, the spectrum domain of the second interference electrical signal is obtained, the components of the second interference electrical signal at a preset frequency point in the spectrum domain are extracted, and the interference frequency component value of the sound wave is determined based on the components of the second interference electrical signal.

[0057] Based on the mixed electrical signal, the spectrum domain of the mixed electrical signal is obtained, the components of the mixed electrical signal at preset frequency points in the spectrum domain are extracted, and the sound wave frequency component value is determined based on the components of the mixed electrical signal.

[0058] The preset frequency points are located within the range of 50Hz to 2500Hz, and the preset frequency points are integer multiples of 50Hz. This frequency range is the frequency range of the acoustic signals of the power equipment, and interference signals outside this range have no effect on the acoustic measurements.

[0059] The formula for calculating the sound pressure level is as follows:

[0060]

[0061] Where SPL is the sound pressure level of the sound wave. For the i-th frequency point f i The sound pressure level at the frequency p ref The acoustic reference sound pressure level is equal to 2 × 10⁻⁶. -5 Pa, where i is the frequency label.

[0062] This invention can eliminate electromagnetic interference coupled into the system via a capacitor diaphragm, an interference path that cannot be blocked by other existing technologies. The capacitor diaphragm of an acoustic sensor must be exposed to air to respond well to sound wave pressure. Therefore, existing technologies cannot electromagnetically shield the interference path coupled through the capacitor diaphragm. This invention uses an interference receiving component to first determine the amount of interference coupled in through the capacitor diaphragm, and then uses an algorithm to eliminate the interference in this part of the acoustic measurement.

[0063] This invention can improve the anti-interference effect of acoustic measurement systems in strong electromagnetic environments. In the frequency range of 50Hz to 2000Hz, this technology can reduce the interference of simple harmonic magnetic fields by up to -38dB.

[0064] Example 2:

[0065] The present invention also proposes a system 200 for measuring sound pressure levels, such as... Figure 3 As shown, it includes:

[0066] The measurement unit 201 is used to control a microphone based on a capacitor diaphragm to measure sound waves at the sound wave measurement point to store a mixed electrical signal including a first interference electrical signal and a sound wave pressure signal. At the same time, it controls a microphone based on an interference receiving component to measure sound waves to store a second interference electrical signal.

[0067] The first computing unit 202 is used to receive the mixed electrical signal and the second interference electrical signal, and preprocess the mixed electrical signal and the second interference electrical signal based on a preset interference signal cancellation algorithm to obtain the interference frequency component value and the sound wave frequency component value.

[0068] The second calculation unit 203 is used to determine the sound pressure level of the sound wave based on the frequency component values ​​of the sound wave.

[0069] The interference receiving component includes: an adjustable microcapacitor, an insulating support, a housing, and connecting terminals;

[0070] The insulating support is a disc with a central opening. The two plates of the adjustable microcapacitor are connected to the connecting terminal through the central opening of the insulating support via connecting wires. The connecting terminal is connected to the preamplifier of the microphone. The adjustable microcapacitor, the insulating support, and the connecting terminal are all housed in the outer casing.

[0071] The adjustable microcapacitor is used to receive interference electrical signals and transmit them to the connection terminal through the connection line. The interference electrical signals are then transmitted to the preamplifier of the microphone through the connection terminal. The insulating support is used to support the adjustable microcapacitor.

[0072] The adjustable microcapacitor has a capacitance range of 50pF to 80pF.

[0073] The first calculation unit preprocesses the mixed electrical signal and the second interference electrical signal based on a preset interference signal cancellation algorithm to obtain the interference frequency component value and the sound wave frequency component value, including:

[0074] Based on the second interference electrical signal, the spectrum domain of the second interference electrical signal is obtained, the components of the second interference electrical signal at a preset frequency point in the spectrum domain are extracted, and the interference frequency component value of the sound wave is determined based on the components of the second interference electrical signal.

[0075] Based on the mixed electrical signal, the spectrum domain of the mixed electrical signal is obtained, the components of the mixed electrical signal at preset frequency points in the spectrum domain are extracted, and the sound wave frequency component value is determined based on the components of the mixed electrical signal.

[0076] The preset frequency point is located in the range of 50Hz to 2500Hz, and the preset frequency point is an integer multiple of 50Hz.

[0077] The formula for calculating the sound pressure level of the second calculation unit is as follows:

[0078]

[0079] Where SPL is the sound pressure level of the sound wave. For the i-th frequency point f i The sound pressure level at the frequency p ref The acoustic reference sound pressure level is equal to 2 × 10⁻⁶. -5 Pa, where i is the frequency label.

[0080] Example 3:

[0081] Based on the same inventive concept, this invention also provides a computer device, which includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to implement corresponding method flows or corresponding functions, thereby implementing the steps of the methods in the above embodiments.

[0082] Example 4:

[0083] Based on the same inventive concept, this invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiments.

[0084] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0085] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0086] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0087] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0088] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0089] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for measuring sound pressure level, characterized in that, The method includes: At the sound wave measurement point, the sound wave is measured by a first microphone based on a capacitor diaphragm to store a mixed electrical signal including a first interference electrical signal and a sound wave pressure signal. At the same time, the sound wave is measured by a second microphone based on an interference receiving component to store a second interference electrical signal. The interference receiving component includes an adjustable microcapacitor, an insulating support, a housing, and connecting terminals. The insulating support is a disc with a central opening. The two plates of the adjustable microcapacitor are connected to the connecting terminals via connecting wires passing through the central opening of the insulating support. The connecting terminals are connected to the preamplifier of the second microphone. The adjustable microcapacitor, the insulating support, and the connecting terminals are all housed within the housing. The adjustable microcapacitor receives the second interference signal and transmits it to the preamplifier via the connecting wires and the connecting terminals. The insulating support supports the adjustable microcapacitor. The capacitance range of the adjustable microcapacitor is 50pF to 80pF. The system receives the mixed electrical signal and the second interference electrical signal, and preprocesses the mixed electrical signal and the second interference electrical signal based on a preset interference signal cancellation algorithm to obtain the interference frequency component value and the sound wave frequency component value. The preprocessing includes: Based on the second interference signal, the spectrum domain of the second interference signal is obtained, the components of the second interference signal at a preset frequency point in the spectrum domain are extracted, and the interference frequency point component value is determined based on the components of the second interference signal. Based on the mixed electrical signal, the spectrum domain of the mixed electrical signal is obtained, the components of the mixed electrical signal at the preset frequency point in the spectrum domain are extracted, and the sound wave frequency point component value is determined based on the components of the mixed electrical signal. The preset frequency point is located in the range of 50Hz to 2500Hz, and the preset frequency point is an integer multiple of 50Hz. The sound pressure level of the sound wave is determined based on the frequency component values ​​of the sound wave.

2. The method according to claim 1, characterized in that, The sound pressure level of the sound wave is calculated according to the following formula: SPL = 10 lg [ ∑ i p 2 (f i ) / p ref 2 ] Where SPL is the sound pressure level of the sound wave, p(f i ) represents the i-th frequency point f i The sound pressure level at the specified frequency, where pref is the acoustic reference sound pressure level and i is the frequency label.

3. A system for measuring sound pressure level, characterized in that, The system includes: The measurement unit is used to control a first microphone based on a capacitor diaphragm to measure the sound wave at the sound wave measurement point to store a mixed electrical signal including a first interference electrical signal and a sound wave pressure signal. At the same time, it controls a second microphone based on an interference receiving component to measure and store a second interference electrical signal. The interference receiving component includes an adjustable microcapacitor, an insulating support, a housing, and connecting terminals. The insulating support is a disc with a central opening. The two plates of the adjustable microcapacitor are connected to the connecting terminals via connecting wires passing through the central opening of the insulating support. The connecting terminals are connected to the preamplifier of the second microphone. The adjustable microcapacitor, the insulating support, and the connecting terminals are all housed within the housing. The adjustable microcapacitor receives the second interference signal and transmits it to the preamplifier via the connecting wires and the connecting terminals. The insulating support supports the adjustable microcapacitor. The capacitance range of the adjustable microcapacitor is 50pF to 80pF. The first calculation unit is used to receive the mixed electrical signal and the second interference electrical signal, and preprocess the mixed electrical signal and the second interference electrical signal based on a preset interference signal cancellation algorithm to obtain the interference frequency component value and the sound wave frequency component value. The first calculation unit is configured to: acquire the spectrum domain of the second interference electrical signal based on the second interference electrical signal, extract the component of the second interference electrical signal at a preset frequency point in the spectrum domain, and determine the interference frequency point component value based on the component of the second interference electrical signal; acquire the spectrum domain of the mixed electrical signal based on the mixed electrical signal, extract the component of the mixed electrical signal at the preset frequency point in the spectrum domain, and determine the sound wave frequency point component value based on the component of the mixed electrical signal; the preset frequency point is located in the range of 50Hz to 2500Hz, and the preset frequency point is an integer multiple of 50Hz; The second calculation unit is used to determine the sound pressure level of the sound wave based on the frequency component values ​​of the sound wave.

4. The system according to claim 3, characterized in that, The second calculation unit calculates the sound pressure level of the sound wave according to the following formula: SPL = 10 lg [ ∑ i p 2 (f i ) / p ref 2 ] Where SPL is the sound pressure level of the sound wave, p(f i ) represents the i-th frequency point f i The sound pressure level at the specified frequency, where pref is the acoustic reference sound pressure level and i is the frequency label.

5. A computer device, characterized in that, include: One or more processors; The one or more processors are used to execute one or more programs; When the one or more programs are executed by the one or more processors, the method as described in claim 1 or 2 is implemented.

6. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed, implements the method as described in claim 1 or 2.

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