CN1333243C - Dynamic measuring system with four sensors for acoustic field spacial distribution of acho signals of bat - Google Patents

Abstract

The present invention belongs to a measuring device of sound field spatial distribution. The present invention is composed of three parts: a signal acquisition module, a signal pretreatment module and a microcomputer interface module, wherein the signal acquisition module is composed of four ultrasonic sensors, a four-channel A/D converter and a conditioning circuit. During measurement, the four sensors are firstly placed to the point which has the distance L with the sound source and has a certain included angle with the level position, and then, the position is continuously changed. The pretreatment of the data obtained by acquisition is carried out; the pretreatment comprises the selection of measuring data and normalization, and the distribution result of bat cry is obtained. The present invention has high sampling rate and carries out waveform sampling to sound signals, and accordingly, the present invention can obtain the analysis on space, time and the frequency domain. The present invention can also be applied to other dynamic measurement, asymmetric measurement, and distribution measurement with stable space fields by making use of a normalization method, and the present invention has wide generalization value.

Description

Four-sensor bat echo signal sound field space distribution dynamic measurement system

Technical field

The invention belongs to sound field space distribution measurement mechanism, particularly a kind of measuring system of bat cry sound field.

Background technology

At present, the research of relevant bat echolocation signal is focus and emphasis in the world always, focus mostly in measurement Research for the surveying instrument of bat echolocation research to the time-frequency characteristic of cry signal itself, and treat the bat signal from acoustics, its space sound field field strength distribution is a very important feature.When using existing surveying instrument the space sound field field strength distribution of bat cry being measured, must carry out the space measurement sampling with big quantity sensor (much larger than four), so that guarantee the requirement of measuring-signal spatial resolution, this just makes the cost of surveying instrument increase greatly, it is very complicated that the measuring system structure becomes, and is unfavorable for promoting the use of in the related scientific research personnel.

Summary of the invention

Call the cost height of acoustic field system in order to overcome existing bat, the deficiency of complex structure aspect, this measuring system provide a kind of low cost, and be simple in structure, is easy to promote the use of, and is convenient to the light and handy instrument of staff's field operation.

This measuring system solves the technical scheme that its technical matters adopts: system is by signal acquisition module, and signal pre-processing module and microcomputer interface module three parts are formed.Signal acquisition module is made up of four ultrasonic sensors, four-way A/D converter, a modulate circuit, and this module is that bat cry signal is nursed one's health, gathered and sampled result is sent among the DSP; Signal pre-processing module is by DSP, FLASH, and data RAM is formed, and is that the data that sampling module is sent here are carried out pre-service, comprises choosing and normalization measurement data; The microcomputer interface module is made up of the RS-232 interface chip, system is connected with microcomputer, being sent in the microcomputer through pretreated measurement data, so that be for further processing.

The present invention measures bat cry sound field space DYNAMIC DISTRIBUTION, better understand bat special ecological niche and uniqueness of acoustic behavior thereof in the ecosystem, and this system has higher sampling rate can carry out waveform sampling to the bat echo signal, reached the analysis on space, time, the frequency domain, filled up both at home and abroad the blank of the measuring system of research in this respect; This cover system utilizes method for normalizing also to can be applicable to other dynamic, asymmetric, as to have stable space field distribution measurement in addition, has wide promotional value.

Description of drawings

Accompanying drawing four-sensor bat echo signal sound field space distribution dynamic measurement system block scheme.

Embodiment

Below in conjunction with accompanying drawing this cover system is further specified

In this instrument, four ultrasonic sensors are received four signal input parts of A/D converter respectively by four modulate circuits, the respective pins that the control pin of A/D converter and output pin are received TMS320VC5402, and A/D converter is controlled by TMS320VC5402, the multichannel buffer serial port of TMS320VC5402 is received on the RS-232 interface chip, and be connected to PC by it, the data pin of TMS320VC5402, address pin and corresponding control pin are connected to data RAM and FLASH simultaneously, TMS320VC5402 are carried out the expansion of data-carrier store and program memory space.

During measurement, four ultrasonic sensors are placed on the fixing skyborne semicircular arc bar, the sound source bat is in the circle centre position of semi arch, the position (angle of sensor and sound source line and horizontal direction) that changes semi arch bar upper sensor is successively come bat cry signal is measured, because it is consistent that No. four sensors can't reach on parameter, promptly the aanalogvoltage of calling its output for same bat is not quite identical, we are added with simple modulate circuit between sensor and A/D converter, be responsible for No. four sensors are reached consistent on input/output relation as far as possible, reduce the error of measuring system; A/D converter is directly received on the digital signal processor TMS320VC5402.The data RAM that we have a 64K word for the expansion of TMS320VC5402 digital signal processor, the digital signal of responsible temporary transient storage A/D converter output and TMS320VC5402 are to the pre-service result of data; A FLASH is used for storing the program of total system, and when giving system power-up, the program that is stored among the FLASH is sent among the TMS320VC5402 by the boot-loader program among the TMS320VC5402, and system automatically performs application program; A RS-232 interface chip is used for TMS320VC5402 is sent among the PC the result of data, and data are for further processing.When this system of use, only needing provides 5V voltage to system, judge by the light on and off of observing system external light-emitting whether system measures end on now taking measurement of an angle, change on the half-round bar No. four sensors then with respect to the angle of horizontal level, restarting systems is carried out the measurement of the next position.

From the data processing angle, the dynamic field of space symmetry is carved at a time, the field strength distribution of certain frequency is symmetrical, so earlier four sensors are put to the distance sound source be L, with the horizontal level angle be 0 the degree, 30 the degree, 60 the degree and 90 degree places, the data that collect are carried out normalization, be about to the reference value S (promptly adopting the data of coming this moment at 0 degree position, angle ultrasonic sensor) that 30 degree, 60 degree and 90 data of spending the position system acquisition are selected divided by us.Next we that each ultrasonic sensor is remained on L apart from the distance of sound source is constant, adjusting sensor is 0 degree, 10 degree, 20 degree and 30 degree with the horizontal level angle, again with system by 10 degree, 20 are spent and 30 degree place sensors are measured data divided by reference value S.As a same reason, fixed range L, adjusting sensor is 0 degree, 40 degree, 50 degree and 60 degree with the horizontal level angle, will be in 40 degree, 50 are spent and 60 degree place sensors are adopted data divided by reference value S.Fixed range L, adjusting sensor is 0 degree, 70 degree, 80 degree and 90 degree with the horizontal level angle, again will be in 70 degree, 80 are spent and 90 degree place sensors are measured data divided by reference value S.Like this, by the repeatedly adjustment of sensor placement having been finished one-level refinement to the sample space.As long as the sensor dimension allows, just can adjust the repeated measurement of sensor angle, carry out multistage refinement.Finally draw the field intensity value of each point on the whole sphere at sound source fixed range L place according to the symmetry characteristic of sound field.In addition, when the sensor dimension reaches capacity but transducer sensitivity can meet the requirements of under the situation, in theory can be by strengthening the purpose that distance L reach further raising angular resolution.Here, the progression of refinement and L value are all decided on the requirement of concrete work.Whole bat sounding sound field intensity distribution plan is drawn in the influence of adopting said method not varied in size by the each cry of bat, to reach the purpose of saving number of sensors.And the spatial resolution of the field strength distribution of depicting, in theory only with to measure number of times relevant, and it doesn't matter with the quantity of placement sensor.Like this, the data storage of system after with normalization is in data RAM, adopt next data for system, whenever adopting the 5K word is one group, calculates in this group sampled data numerical value greater than the number of scaled values A (can artificially set), when this number during greater than scaled values B (can think setting), these group data are sent in the microcomputer, be for further processing, otherwise do not get this group number, carry out next group DATA REASONING.Such purpose is to guarantee that the data of surveying are to sample when bat cry amplitude is big, and has saved the size that extends out the data RAM space.

A/D converter is selected the high speed 10 bit parallel A/D THS10064 chips of TI company for use, and when its four passages were worked simultaneously, the high-conversion rate of each passage reached 1.5MSPS; Data RAM is selected ISSI high-speed data memory I S61LV6416 chip for use, and image data is stored; FLASH selects for use the Am29AL800B chip of AMD to carry out procedure stores, the automatic loading of program when being used to start shooting; TMS320VC5402 adopts the TMS320VC5402 digital signal processor of TI company; RS-232 interface adopts the MAX3238 level transferring chip of Maxim company.

Claims (2)

1. four-sensor bat echo signal sound field space distribution dynamic measurement system, it is characterized in that system is by signal acquisition module, signal pre-processing module and microcomputer interface module three parts are formed, signal acquisition module is by four ultrasonic sensors, a four-way A/D converter, modulate circuit is formed, signal pre-processing module is by DSP, FLASH, data RAM is formed, the microcomputer interface module is made up of the RS-232 interface chip, four ultrasonic sensors are received four signal input parts of A/D converter respectively by four modulate circuits, the respective pins that the control pin of A/D converter and output pin are received TMS320VC5402, and A/D converter is controlled by TMS320VC5402, the multichannel buffer serial port of TMS320VC5402 is received on the RS-232 interface chip, and be connected to PC, the data pin of TMS320VC5402 by it, address pin and corresponding control pin are connected to data RAM and FLASH simultaneously.

2. press the measuring method of the described four-sensor bat of claim 1 echo signal sound field space distribution dynamic measurement system, when it is characterized in that measuring, four ultrasonic sensors are placed on the fixing skyborne semicircular arc bar, the sound source bat is in the circle centre position of semi arch, change the position of semi arch bar upper sensor successively, promptly earlier four sensors are put to the distance sound source be L, with the horizontal level angle be 0 the degree, 30 degree, 60 degree and 90 degree places, the data that collect are carried out normalization, be about to 30 degree, the reference value S that the data of 60 degree and 90 degree position system acquisition are selected divided by us, promptly adopt the data of coming this moment at 0 degree position, angle ultrasonic sensor, next it is constant each ultrasonic sensor to be remained on L apart from the distance of sound source, adjusting sensor and horizontal level angle is 0 degree, 10 degree, 20 degree and 30 degree, again system is spent by 10,20 degree and the measured data of 30 degree place sensors are divided by reference value S, equally, fixed range L, adjusting sensor and horizontal level angle is 0 degree, 40 degree, 50 degree and 60 degree, will be at 40 degree, the data that 50 degree and 60 degree place sensors are adopted are divided by reference value S, fixed range L, adjusting sensor and horizontal level angle is 0 degree, 70 degree, 80 degree and 90 degree, again will be at 70 degree, 80 degree and the measured data of 90 degree place sensors are divided by reference value S, by the repeatedly adjustment of sensor placement having been finished one-level refinement to the sample space, adjust the repeated measurement of sensor angle, carry out multistage refinement, the data that sampling module is sent here are carried out pre-service, comprise choosing and normalization to measurement data, finally draw the field intensity value of each point on the whole sphere at sound source fixed range L place, also can reach further raising angular resolution by the increasing distance L according to the symmetry characteristic of sound field.