CN101033616A - Basic structure dynamic measuring instrument capable of asynchronous collecting signal and synchronous correcting - Google Patents
Basic structure dynamic measuring instrument capable of asynchronous collecting signal and synchronous correcting Download PDFInfo
- Publication number
- CN101033616A CN101033616A CN 200610049782 CN200610049782A CN101033616A CN 101033616 A CN101033616 A CN 101033616A CN 200610049782 CN200610049782 CN 200610049782 CN 200610049782 A CN200610049782 A CN 200610049782A CN 101033616 A CN101033616 A CN 101033616A
- Authority
- CN
- China
- Prior art keywords
- signals
- asynchronous
- signal
- microprocessor
- measuring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000001360 synchronised effect Effects 0.000 title claims description 8
- 230000001133 acceleration Effects 0.000 claims abstract description 14
- 238000012360 testing method Methods 0.000 claims abstract description 10
- 238000005070 sampling Methods 0.000 claims description 26
- 238000000034 method Methods 0.000 claims description 16
- 238000012937 correction Methods 0.000 claims description 6
- 108010076504 Protein Sorting Signals Proteins 0.000 claims description 4
- 238000004891 communication Methods 0.000 claims description 3
- 238000004458 analytical method Methods 0.000 claims description 2
- 238000005259 measurement Methods 0.000 claims description 2
- 230000003321 amplification Effects 0.000 abstract 1
- 238000003199 nucleic acid amplification method Methods 0.000 abstract 1
- 238000001514 detection method Methods 0.000 description 8
- 238000005516 engineering process Methods 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000007547 defect Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
Images
Landscapes
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
A dynamic admeasuring apparatus with basic structure which can collect signals asynchronously and correct synchronously contains two power sensors and two acceleration sensors. The sensors are equipped on both sides of pile body below the tested pile block symmetrically. Each sensor joints to AD amplifier via amplification circuit and the output of the amplifier connects and communicates with microprocessor by A/D transducer. Set pile foundation testing module which can analyze its quality based on signals from different sensors in the microprocessor. The admeasuring apparatus also contains a selection control circuit being used to establish four selection channels for sensors. The output of the selection control circuit connects with the parallel interface of the computer through an A/D transducer. With the controlling of microprocessor, line controller collects signals from four channels alternatively and asynchronously. The signals are fitted for reducing and synchronizing to get integrated signal waveforms. The invention provides a dynamic admeasuring apparatus with basic structure having simple circuit structure and low cost.
Description
(I) technical field
The invention relates to a testing technology of pile foundation quality, in particular to a foundation structure dynamic measuring instrument for synchronously correcting asynchronously acquired signals.
(II) background of the invention
With the increase of high-rise buildings, bridges and large civil engineering, pile foundations are widely applied. Due to the influence of geological conditions and construction processes, the pile foundation sometimes has defects of breakage, unevenness and the like, so that the load capacity of the pile is reduced. Therefore, these piles cannot withstand a large load from a high-rise building and a bridge, so that some accidents, such as inclination and collapse of the building or the bridge, occur. In order to ensure the engineering quality, the pile foundation needs to be detected.
The traditional pile foundation quality detection methods mainly comprise a coring method, an ultrasonic method, a ray method and the like, and with the continuous improvement of fluctuation theories, vibration engineering, signal analysis technologies, electronic technologies and microprocessor technologies, the vibration method and the fluctuation method dynamic detection technologies are rapidly developed and widely applied, wherein the methods are divided into a high-strain detection method and a low-strain detection method. In the existing pile structure quality detection, whether the high strain detection method or the low strain detection method is implemented by hammering a pile foundation, acquiring time-course curves of axial strain of a representative pile body section and pile body motion acceleration of a pile top accessory, capturing motion speed and stress strain generated in the propagation process of stress waves by a sensor and converting the motion speed and the stress strain into electric signals, converting the electric signals into digital signals by a processing circuit and submitting the digital signals to a special detection instrument, processing the signals into an F-v diagram, and analyzing curve waveforms in the diagram to judge the quality of the pile foundation.
In order to reduce the influence of eccentric hammering which may occur, two strain sensors and two acceleration sensors must be installed during the test, and the four paths of electric signals must be subjected to A/D conversion simultaneously. This requires four a/D converters to operate simultaneously, and a dedicated test instrument to process and map four digital signals simultaneously, which is expensive and complicated.
Disclosure of the invention
In order to overcome the defects of complex structure and high cost of the conventional infrastructure dynamic measuring instrument, the invention provides the infrastructure dynamic measuring instrument for asynchronously collecting signals and synchronously correcting, which has a simple circuit structure and low cost.
The technical scheme adopted by the invention for solving the technical problems is as follows:
a dynamic measuring instrument of foundation structure for asynchronous signal acquisition and synchronous correction comprises two force sensors and two acceleration sensors, wherein the two force sensors and the two acceleration sensors are symmetrically arranged at two sides of a pile body below the pile top of a pile foundation to be measured, each sensor is connected to an AD amplifier through an amplifying circuit, the output of the amplifier is in communication connection with a microprocessor through an A/D converter, a pile foundation testing module for analyzing the quality of the pile foundation according to the signals of each sensor is arranged in the microprocessor, the dynamic measuring instrument of foundation structure for asynchronous signal acquisition further comprises a selection control circuit for setting up selection channels of four sensors, the input end of the selection control circuit is respectively connected with the output of four AD amplifiers, the output of the selection control circuit is connected with a parallel interface of the microprocessor through an A/D converter, the microprocessor also comprises an asynchronous sampling control module for controlling four-path signal asynchronous sampling, and an asynchronous fitting module for performing curve fitting on the four groups of collected sensor signals, wherein the asynchronous sampling control module is connected with a line switch of the selection control circuit, the input end of the asynchronous fitting module is connected with a parallel interface of the microprocessor, and the output end of the asynchronous fitting module is connected with the pile foundation testing module.
Furthermore, the asynchronous sampling control module is used for setting the sampling width to toWith a period of 4to，0-toMeasuring the first signal at a time to-2toMeasuring the second path of signal at a time, 2to-3toMeasuring the third signal at a time, 3to-4toAnd measuring the fourth path of signals at the moment.
And the asynchronous fitting module is used for respectively fitting four paths of signals in the asynchronous acquisition, and adopting a three-point defined parabolic method to obtain any continuous three points in the signal sequence to fit a section of parabolic curve section.
The working principle of the invention is as follows: the asynchronous data acquisition synchronous correction technology only utilizes one A/D converter to carry out A/D conversion, simultaneously utilizes a parallel interface of a PC to carry out data acquisition, and utilizes a microprocessor to restore four paths of data, thereby being convenient, rapid and lower in cost.
The invention has the following beneficial effects: 1. the structure is simple; 2. the cost is low; 3. the use is convenient and fast.
(IV) description of the drawings
Fig. 1 is a structural view of a pile foundation measuring instrument.
Fig. 2 is a schematic diagram of asynchronous acquisition of signals.
Fig. 3 is a schematic diagram of curve fitting.
(V) detailed description of the preferred embodiments
The invention is further described below with reference to the accompanying drawings.
Referring to fig. 1, 2 and 3, an infrastructure dynamic measuring instrument for asynchronously collecting signals and synchronously correcting comprises two force sensors 1 and two acceleration sensors 2, wherein the two force sensors 1 and the two acceleration sensors 2 are symmetrically arranged at two sides of a pile body below a pile top of a pile foundation to be detected, each sensor is connected to an AD amplifier 4 through an amplifying circuit 3, the output of the amplifier 4 is in communication connection with a microprocessor 7 through an a/D converter 6, a pile foundation testing module 8 for analyzing the quality of the pile foundation according to signals of the sensors is arranged in the microprocessor 7, the infrastructure dynamic measuring instrument for asynchronously collecting signals further comprises a selection control circuit 5 for setting up selection channels of four sensors, the input end of the selection control circuit 5 is respectively connected with the output of the four paths of AD amplifiers 4, and the output of the selection control circuit 5 is connected with a parallel interface 9 of the microprocessor through an a/D converter 6 And the microprocessor 7 further comprises an asynchronous sampling control module 10 for controlling four-path signal asynchronous sampling, and an asynchronous fitting module 11 for performing curve fitting on the four groups of acquired sensor signals, wherein the asynchronous sampling control module 11 is connected with a line switch of the selection control circuit 5, the input end of the asynchronous fitting module 11 is connected with a parallel interface 9 of the microprocessor, and the output end of the asynchronous fitting module 11 is connected with the pile foundation testing module 8.
The asynchronous sampling control module 11 is used for setting the sampling width as toWith a period of 4to，0-toMeasuring the first signal at a time to-2toMeasuring the second path of signal at a time, 2to-3toMeasuring the third signal at a time, 3to-4toAnd measuring the fourth path of signals at the moment.
The working process of the embodiment is as follows: a force sensor and an acceleration sensor are arranged in the center of one side of a pile body below the pile top of a pile foundation to be tested, and meanwhile, the force sensor and the acceleration sensor are also arranged on the symmetrical surface, so that the positions are kept symmetrical. Each sensor is connected to an AD amplifier through an amplifying circuit and then is uniformly connected to a selection controller, signals selected by the selection controller are sent to an A/D converter for analog/digital conversion, and finally digital signals are sent to a parallel interface of a microprocessor. And simultaneously, the selection controller and the A/D converter are controlled through a parallel interface of the microprocessor.
The technology is characterized in that a hammer is used for applying impact on a pile to generate elastic waves and impedance, two force sensors arranged near the top of the pile foundation are used for receiving stress wave signals on the pile foundation to generate charge signals, meanwhile, two acceleration sensors are used for receiving acceleration signals on the pile foundation to generate two paths of charge signals, and each path of charge signals are converted into voltage signals through an amplifying circuit to be output. The voltage signal is then signal amplified by an AD amplifier, and the amplified signal is sent to a selection controller. The microprocessor controls the selection controller to select the channels for sampling the four signals, wherein the four signals are not collected simultaneously, but are collected sequentially in sequence through a time interval. The signal sampled by the control selector is sent to the A/D converter for analog/digital conversion, converted into eight-bit digital signal, and finally sent to the parallel interface of the microprocessor, because the parallel bidirectional interface supports one-time reading of eight-bit data, the microprocessor can collect the data of the parallel interface by programming to obtain the signal data.
The invention focuses on asynchronous sampling of four signals by controlling the selector, i.e. periodic measurement is performed on each signal, for example, the sampling width is toWith a period of 4toIs 0-toMeasuring the first signal at a time to-2toMeasuring the second path of signal at a time, 2to-3toMeasuring the third signal at a time, 3to-4toAnd measuring the fourth path of signal at any moment, then measuring the first path of signal again, and repeating the steps.
In this embodiment, the a/D converter ADS7809 is adopted, the sampling frequency is 100K, and therefore the sampling time interval is 10 μ s each time, and since the four signals occupy the same bandwidth, the sampling time interval for one signal is 40 μ s, and the sampling pattern is shown in fig. 2. After the digital signals are input into the microprocessor, the microprocessor sequentially groups the digital signals, the signals are divided into four groups, the sequentially acquired digital signals are sequentially classified into four groups, as shown in fig. 2, all signals (i) are recombined into a sequence of a group of digital signals, all signals (ii) are also recombined into a sequence of a group of digital signals, and the signals (iii) and the signals (iv) are processed in the same way. The result is a sequence of samples of the four-way signal.
In the inventionAnd finally, performing curve fitting on the four groups of signals by a parabolic method. Here the signal is fitted and reduced using a three-point defined parabolic method: taking any continuous three points P in signal sampling sequence0、P1、P2A parabolic curve segment can be fitted, where the expression is given by a parameter vector, i.e.
P(t)＝A0+A1t+A2t2(0≤t≤1) (1)
The curve is composed of a series of A0As a starting point, in A1Taken in the direction t, at A2In the direction of t2The curve is drawn and should therefore be parabolic. The parabola satisfies:
(1) when t is 0, the parabola passes through P0Point and P0P1The lines are tangent.
(2) When t is 1, the parabola passes through P2Point and P1P2The lines are tangent.
The parabola can be represented by P0P1P2The parameter expression defined by three points is shown.
P' (t) ═ a can be obtained by differentiating t in formula (1)1+2*A2T, then
P(0)＝A0＝P0 (2)
P(1)＝A0+A1+A2＝P2 (3)
P’(0)＝A1＝K(P1-P0) (4)
P’(1)＝A1+2*A2＝L(P2-P1) (5)
Where K, L is a constant. Can be arranged out
2(P2-P0)＝K(P1-P0)+L(P2-P1)
Due to (P)2-P1) And (P)1-P0) The linearity is irrelevant, so K-L-2. Thus, it is possible to provide
As expressed in component form, i.e. Wherein,
A1＝2(X1-X0)
A2＝X0-2X1+X2
B1＝2(Y1-Y0)
B2＝Y0-2Y1+Y2
therefore, the digital signal value of any time t in the three-point time interval can be obtained by substituting the digital signals of the continuous three points in the signal sequence, and therefore, the section of the parabola curve can be fitted. Therefore, a plurality of curve segments are required to be smoothly connected into an arbitrary curve. Here, it is necessary to determine a common tangent at the junction of two curved segments, such as P in FIG. 31～P5Curve of (1), we first take P2、P3Middle point Q of1Then with P1、P2、Q1For the three-point range, calculate the curve, then take P3、P4Middle point Q of2With Q1、P3、Q2For the three-point range, the curve segment is calculated, and therefore, the complete smooth signal curve can be obtained according to the signal sequence with any length.
The above calculation process can be realized by programming a microprocessor, and a smooth signal curve can be fitted by taking a proper time interval point. Meanwhile, because sampling is carried out asynchronously, for example, the initial sampling points of four groups of signals respectively have a difference of t in sequence0The four groups of signals can be simultaneously given 4t0The sampling points are started, so that synchronous signal curves of four groups of signals can be obtained. Therefore, four signal curves, namely two stress curves and two acceleration curves, can be restored on the microprocessor through the processes and are used for detecting the quality of the pile foundation.
Claims (3)
1. The utility model provides an asynchronous acquisition signal's of asynchronous acquisition signal synchronous correction infrastructure dynamic measurement appearance, includes two force sensor and two acceleration sensor, and two force sensor, two acceleration sensor symmetries are installed in the following pile body both sides of pile bolck of the pile foundation that awaits measuring, and every sensor is connected to the AD amplifier through amplifier circuit, and the output of amplifier passes through AD converter and microprocessor communication connection, microprocessor in be equipped with the pile foundation test module that carries out pile foundation quality analysis according to the signal of each sensor, its characterized in that: the basic structure dynamic measuring instrument for the asynchronous acquisition signals further comprises a selection control circuit used for setting selection channels of four sensors, the input end of the selection control circuit is respectively connected with the output ends of the four AD amplifiers, the output ends of the selection control circuit are connected with a parallel interface of a microprocessor through an A/D converter, the microprocessor further comprises an asynchronous sampling control module used for controlling the asynchronous sampling of the four signals, and an asynchronous fitting module used for performing curve fitting on the four acquired sensor signals, the asynchronous sampling control module is connected with a line switch of the selection control circuit, the input end of the asynchronous fitting module is connected with the parallel interface of the microprocessor, and the output end of the asynchronous fitting module is connected with the pile foundation testing module.
2. An asynchronously acquired signal synchronous correction infrastructure dynamics measurer as claimed in claim 1, in which: the asynchronous sampling control module is used for setting the sampling width as toWith a period of 4to，0-toMeasuring the first signal at a time to-2toMeasuring the second path of signal at a time, 2to-3toMeasuring the third signal at a time, 3to-4toAnd measuring the fourth path of signals at the moment.
3. An infrastructure dynamics meter for synchronous correction of asynchronously acquired signals as claimed in claim 1 or 2, wherein: the asynchronous fitting module is used for respectively fitting four paths of signals in asynchronous acquisition, and any continuous three points in a signal sequence are taken by adopting a three-point defined parabolic method to fit a parabolic curve section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100497823A CN100480669C (en) | 2006-03-10 | 2006-03-10 | Basic structure dynamic measuring instrument capable of asynchronous collecting signal and synchronous correcting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100497823A CN100480669C (en) | 2006-03-10 | 2006-03-10 | Basic structure dynamic measuring instrument capable of asynchronous collecting signal and synchronous correcting |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101033616A true CN101033616A (en) | 2007-09-12 |
| CN100480669C CN100480669C (en) | 2009-04-22 |
Family
ID=38730343
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006100497823A Expired - Fee Related CN100480669C (en) | 2006-03-10 | 2006-03-10 | Basic structure dynamic measuring instrument capable of asynchronous collecting signal and synchronous correcting |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100480669C (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102867122A (en) * | 2012-09-11 | 2013-01-09 | 中国航天科技集团公司第五研究院第五一三研究所 | Parabolic waveform fitting method of interference data |
| CN103077006A (en) * | 2012-12-27 | 2013-05-01 | 浙江工业大学 | Multithreading-based parallel executing method for long transaction |
| CN103898928A (en) * | 2014-03-12 | 2014-07-02 | 广东省建筑科学研究院 | Improved high strain method |
| CN105544623A (en) * | 2016-01-29 | 2016-05-04 | 湖南省计量检测研究院 | Calibrating device and calibrating method applied to dynamic measuring instrument of foundation pile |
| CN106726031A (en) * | 2016-12-27 | 2017-05-31 | 北京石油化工学院 | A kind of measurement apparatus of prosthetic socket Evaluation of Comfort |
| CN107071595A (en) * | 2017-05-12 | 2017-08-18 | 武汉邮电科学研究院 | The Transmission system of asynchronous control signal |
| CN107331262A (en) * | 2017-08-21 | 2017-11-07 | 东华理工大学 | Foundation pile integrity analysis and teaching experiment bracket signal synchronous acquisition device |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104196065B (en) * | 2014-09-27 | 2016-07-06 | 上海岩联工程技术有限公司 | A kind of intelligent wireless Large strain sensor and wireless high strain monitoring method |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3960008A (en) * | 1974-12-12 | 1976-06-01 | Goble George G | Pile capacity testing means |
| FR2461066A1 (en) * | 1979-07-09 | 1981-01-30 | Coelus Gaspar | METHOD AND APPARATUS FOR DYNAMIC PIEUX TESTING |
| CN2078875U (en) * | 1990-07-31 | 1991-06-12 | 胡学宁 | Nondestructive detector of strength of sintered brick |
| CN2252334Y (en) * | 1996-01-16 | 1997-04-16 | 中国建筑材料科学研究院 | Cement mortar jolt ramming stand |
| CN2919233Y (en) * | 2006-03-10 | 2007-07-04 | 浙江工业大学 | Foundation structure dynamic measuring meter |
-
2006
- 2006-03-10 CN CNB2006100497823A patent/CN100480669C/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102867122A (en) * | 2012-09-11 | 2013-01-09 | 中国航天科技集团公司第五研究院第五一三研究所 | Parabolic waveform fitting method of interference data |
| CN103077006A (en) * | 2012-12-27 | 2013-05-01 | 浙江工业大学 | Multithreading-based parallel executing method for long transaction |
| CN103077006B (en) * | 2012-12-27 | 2015-08-26 | 浙江工业大学 | A kind of Long routine executed in parallel method based on multithreading |
| CN103898928A (en) * | 2014-03-12 | 2014-07-02 | 广东省建筑科学研究院 | Improved high strain method |
| CN105544623A (en) * | 2016-01-29 | 2016-05-04 | 湖南省计量检测研究院 | Calibrating device and calibrating method applied to dynamic measuring instrument of foundation pile |
| CN106726031A (en) * | 2016-12-27 | 2017-05-31 | 北京石油化工学院 | A kind of measurement apparatus of prosthetic socket Evaluation of Comfort |
| CN107071595A (en) * | 2017-05-12 | 2017-08-18 | 武汉邮电科学研究院 | The Transmission system of asynchronous control signal |
| CN107071595B (en) * | 2017-05-12 | 2019-06-25 | 武汉邮电科学研究院 | The Transmission system of asynchronous control signal |
| CN107331262A (en) * | 2017-08-21 | 2017-11-07 | 东华理工大学 | Foundation pile integrity analysis and teaching experiment bracket signal synchronous acquisition device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100480669C (en) | 2009-04-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101033616A (en) | Basic structure dynamic measuring instrument capable of asynchronous collecting signal and synchronous correcting | |
| CN108106541A (en) | A kind of bridge cable force measuring method based on video image identification | |
| US20220412867A1 (en) | Tbm-mounted system and method for quickly predicting compressive strength of rocks based on rock mineral composition and fabric characteristics | |
| CN113605887B (en) | Deep drilling complex environment local wall stress relief test method and system | |
| CN101762347B (en) | Method for measuring rope force of multi-span steel stay rope by using half-wave method | |
| CN106768574B (en) | Method for measuring cable force of linear model after cable anchoring based on magnetic flux method correction | |
| CN112985671A (en) | Damage judgment method based on full-cable-system cable force test and error adaptive analysis | |
| CN102565484A (en) | Digital oscilloscope with fine trigger function | |
| CN111521681A (en) | Concrete internal damage assessment method based on piezoelectric ceramic shear wave energy loss | |
| CN106855539A (en) | A kind of anchor rod nondestructive testing method and equipment based on stress wave | |
| CN112924016A (en) | Cantilever beam natural frequency measuring system and method | |
| CN104316009A (en) | Dynamic measurement error compensation method based on pull rope encoder measuring system | |
| CN2919233Y (en) | Foundation structure dynamic measuring meter | |
| CN101701882B (en) | Rapid identification method for tower structure rigidity | |
| CN117705091B (en) | High-precision attitude measurement method based on wide-range quartz flexible accelerometer | |
| CN105004798B (en) | A kind of signal intelligent amplifying device and method for foundation pile ultrasonic detecting equipment | |
| CN109374171B (en) | Method for detecting in-service stay cable force | |
| CN207964226U (en) | Large-scale component vibration shape detection device based on doppler optical displacement method | |
| CN112985672A (en) | Prestressed cable force analysis method based on non-contact space vibration test | |
| CN218995261U (en) | Nondestructive testing device for concrete filled steel tube excitation sound measurement | |
| CN107764896B (en) | Testing device and method for testing soil wave velocity of centrifugal machine model by piezoelectric element array | |
| CN116359014A (en) | System and method for detecting strength of juvenile concrete | |
| CN113188488B (en) | Nondestructive measuring method for length of anchor rod | |
| JP2000121743A (en) | Evaluating method for seismic shake distribution | |
| CN115728513A (en) | Novel impact acceleration measuring device and measuring method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090422 Termination date: 20120310 |