AwaSys - History and change log

AwaSys History

Aalborg University was among the first laboratories in the world to construct a multi-directional wave basin. The wave basin was put into operation in the beginning of the 1980'ties. A large improvement in 3-D wave generation quality was archived as the basin was designed with uniquely vertically hinged piston generators instead of the commonly seen box types. For this basin the wave synthesis and control software ProfWACO was developed in house by Mr. Peter Frigaard who today is head of the department.

Later on a wider basin and also several flumes were built. For all these facilities Aalborg University has been running the ProfWACO wave generation software. In the late 1980'ties the first version of the AwaSys software for active wave absorption in wave flumes was developed based on digital filtering of wave gauge signals in the far field. This method was invented by the staff of the laboratory and has later also been included in several numerical models.

Both the ProfWACO and AwaSys software were running under the operating system DOS. These systems have co-existed and been updated until approximately year 2000 and has been delivered to several laboratories worldwide. Hereafter, it was decided to rewrite the AwaSys software in order to transform it into the windows application AwaSys4. In 2004 the 3-D wave generation routines from ProfWACO was added to the windows program to form AwaSys5 able to run both in flumes and basins but only with 2-D active absorption.

In 2011 AwaSys 6 (Win XP- Win 10 supported) was released which include active absorption of multi-directional waves using digital filtering of signals from wave gauges on the paddle faces and several other improvements. 

In 2017 Awasys 7 was released (Win 7 - Win 10 supported) in both 32 and 64 bit versions. AwaSys 7 is developed for the worldwide largest deep water basin under construction in Korea. AwaSys 7 was a significant step forward in several areas especially for wave basins.

The history indicate that improvements to our software are continously made in order to maintain a market leading future proof wave generation solution.

In all steps of development the implementations has been thoroughly tested against known results and in real application in our laboratory facilities. This has led to an extremely robust, well tested and state of the art wave generation software package that now is running in several laboratories worldwide. 

Change log for AwaSys 7

January 13, 2021
- In the sea state validation a few floating point errors for very deep water waves has been fixed.
- Fixed that for GWP spectrum form factor was not model scaled.
- Wave calculator: Fixed waves to time when called with model scale different from unity.

December 18, 2020
- Added a warning for gaussian wave packets if the three term Taylor series expansion of the dispersion equation is not working well.

December 04, 2020
- Fixed that the second order wave generation may stall due to a bug in the prallel programming library. A work around of resetting the parallel programming thread pool between each test is now applied.

November 25, 2020
- In dual face setups it allowed not to generate waves that could only be generated by 2nd face (spurious waves on first face too high). Now it allows to generate the seastate as long as it can be generated by one of the faces.

November 23, 2020
- Performance curve: Correcting error in force estimates for hinged wavemakers.

November 19, 2020
- Performance curve: Correcting errors for hinged wavemakers and power estimates in deep water.

November 18, 2020
- In the performance curve added the possibility to deactive the nearfield in the breaking and overtopping criteria.
- In the performance dialogue added the possibilty to use 2nd order theory.
- Warnings are now given if the sea state exceeds the performance curve.
- Changed realtime overload check of self-test and measure gain and delay dialogues to be identical to those used during normal generation.

November 9, 2020
- Added possibilty to show the facility performance curve (long-crested linear waves head-on to the wavemaker, no active absorption). In order to show the curve the maximum force and power needs to be specified in preferences.
- Fixed that at startup output file folder was not restored to value used last.

October 26, 2020
- In a basin configuration using traditional DAQ a warning is now given if then feedback signal indicate that the paddle is not in expected initial position.
- Optimized the disconnects and connects upon daq preferences changes.
- Fixed a bug in interpolating custom biesel transfer file data.

October 21, 2020
- Fixed that the dialogue Measure Paddle Gain and Delay exported mechanical transfer files with system decimal separator and not dot as assumed when reading the file.
- Check mechanical transfer file for negative or zero gains.
- If user cancels the startup dialogue on paddle needs to move to center then disconnect from DAQ.
- Fixed various errors related to operation without DAQ connection and thus it is now possible to generate replay files without DAQ connection.

October 14, 2020
- Fixed a bug in Measure Gain and Delay that send the value in meter to the daq instead of in volts.

October 9, 2020
- Fixed a memory leak when using replay files (introduced in version from June 22, 2020).

September 21, 2020
- Added the possibility to generate Gaussian Wave Packets (Clauss and Bergmann, 1986).
- General update of the calculator so wavelength and steepeness now reflects the selected wave height and period parameters. This brings many possibilities as for example the mean wave steepness and peak wave period can be specified and using the calculator the significant wave height is calculated.
- The translation between peak and mean period in the calculator is now based on actual spectral moments instead of typical ratios.
- Fixed color theme of the calculator.

August 20, 2020
- More detailed error when reading mechanical transfer file was unsuccessful.
- Fixed no error was given if wave amplification file was invalid.

July 15, 2020
- Fixed warning on recommended irregular generation method was sometimes wrong.

June 22, 2020
- Fixed that after addiding support for wavemakers with custom Biesel transfor fuction (update 28.01.2020) an error was given upon deletion of entries in the  batch list.

June 15, 2020
- Fixed that after last update irregular waves with white noise generation method gave even for no grouping error "Wave grouping only supported in InvFFT Random Phase generation method".

May 28, 2020
- Added further posibilities for making focused waves (crest, trough or zero-crossing focused waves).
- Furthermore, it is now possible to define the time at which the focusing should occur and also the possibility to specify the amplitude of the focused freak wave instead of Hm0.
- Added DPI aware icons on buttons.
- Changed about screen layout to be identical to EPro and WaveLab.
- Added hinge eccentricity to preference dialogue (was only available in the ini file).
- Fixed that on windows system with 12 hour time format (AM/PM) the elapsed and remaining test time was wrong displayed.

January 28, 2020
- Added support for wavemakers with no analytical solution for the Biesel transfer function (plunger type). Transfer constants are measured experimentally and given in an ASCII file.
- Measure gain and delay dialogue has been updated with the purpose to automatically measure the Biesel transfer file.

November 11, 2019
- Fixed that after adding cnoidal regular wave generation the Bullseye coordinate could not be specified.
- Changed error to a warning if stream function regular wave generation is chosen in deep water.
- Reverted to previous version of the parallel programming library to fix an issue with wave generation using 2nd order generation might stall with 0% CPU.

October 23, 2019
- Fixed that calibration report could not be generated if some gauges are unchecked for calibration.

September 23, 2019
- Added ad-hoc unified for generation of highly nonlinear irregular waves based on Boussinesq numerical wave model input. The method produces a similar advantage in generation of nonlinear irregular waves as the stream function method do for regular waves. The input to the method comes from a numerical model (Boussinesq type) that runs on the GPU automatically in AwaSys. A fast GPU (graphic card) is needed for the test preparation time to be reasonable. The method is currently limited to long-crested waves head-on to the wavemaker (2D). The method has been used internally for several years, but is now reached a level where it is open to all users.
- Fixed access violation when making the wave gauge calibration report when the gauges have a fixed zero offset. Moreover, fixed showing incorrect maximum error percentage in the report in case calibration range is not unipolar.

August 22, 2019
- Added lines in awd and awg headers to see if test is replay from file and selected replay sample interval. This info is now automatically read and used in the inspect replay file dialogue.
- Added warnings for which wavemaker theory to used with criteria based on Eldrup and Lykke Andersen (2019), Applicability of nonlinear wavemaker theory, Journal of Marine Science and Engineering.
- Fixed that when cnoidal theory was not valid the spectrum was still being calculated (with errors).
- Fixed that for cnoidal wave theory the wrong frequency was used for the mechanical compensation.
- Fixed a problem with cnoidal wave generation sometimes failing during wave generation preparation (initial paddle position not being correctly set).

August 8, 2019
- Added generation of cnoidal regular waves (Fentons 5ht order theory). The cnoidal wave generation is only relevant when stream function does not converge to a solution, i.e. long waves close to breaking.
- Fixed that clipping was sometimes reported as reduced stroke clipping even if full stroke was available for all paddles.
- For SW waves the farfield surface elevation in the replay file is now given in the paddle mean position (in agreement with all other wave types).

July 9, 2019
- Added Ochi-Hubble wave spectra. 

July 8, 2019
- Added posibility to make a calibration report on the wave gauge calibration.

May 13, 2019
- Added dialogue to inspect replay signals prior to performing the test. This dialogue shows the clipped and unclipped signals and may thus be used to examine the amount of clipping prior to a test. Moreover, the dialogue may be used to inspect test signals from an already performed test (aws, awd and awg files). The first option is available from the replay stored signal tab. The latter one from the main menu under Tools.
- Added additional checks on replay files.
- On replay from file added also info on the maximum asked distance between paddle neighbours.
- Changed clipping reporting to better include paddles with reduced stroke (ex. paddles in the corner of a dual face basin).
- Fixed that sometimes test was aborted due to excessive velocity when it was actually stroke that was exceeded. This might have caused some tests to be aborted without the need to do it.

April 2, 2019
- In the wave generation dialogue added the possibility to see the signal of the auxiliary channels.

March 21, 2019
- On replay from file added maximum demanded stroke, velocity and acceleration to tree view.

January 16, 2019
- Updated development studio to newest version which improved high DPI support and per monitor DPI support.
- Corrected self-test not giving correct results with negative wave gauge calibration constants. 
- Fixed that in measure gain and delay dialogue (create mechanical transfer) unipolar output signals led to validation error on the output amplitude.
- Fixed that the main dialogue showed wrong values for the feedback signal in metre (used not the correct offset).
- Zero or very small wave gauge calibration constants no longer allowed.

November 26, 2018
- In calibrate wave gauge dialogue added the channel description. Moreover, deselected gauges are not shown with new values or comments.

November 21, 2018
- In batch mode the existance of the output directories was previously only checked when the test is added to the batch. Now this is also checked upon start of the test.

November 08, 2018
- Added possibility to store the feedback signal in the modified demand (awd) file.

November 06, 2018
- Added backward and forward stroke factors to be able to specify paddles in a basin with less stroke than the default one. This is especially useful for the paddles in the corner of a L-shaped basin.
- Update of the soft clipping algorithm to handle above situation. This led to a general improvement of the procedure that clips for maximum distance between paddle neighbors.
- Ignore frequencies less than or equal to zero in custom spectra files.
- Other minor bug fixes.

October 17, 2018
- Fixed error with gauge channel numbers when using daq manufacturer VTI ethernet and more than one node and more than one gauge per paddle.

September 11, 2018
- Added auxiliary channels in order to be able to define also extra channels to sample when active absorbers are define (secondary channels).

August 25, 2018
- Fixed that paddle hit end stops with slightly higher acceleration than allowed. This may cause VTI controller to invalidate the setpoint and having difficulties reattaching to the correct AwaSys signal.
- With respect to the change of January 25th then the method for selecting corner paddles has been improved. The same has the error message so the reason for aborting is more clear.

April 25, 2018
- GUI improvements with respect to selecting replay files.

April 24, 2018
- Fixed that 3-D absorption factor did not take into account that individual paddles might have disabled active absorption for example because of faulty wave gauge. Thus all paddles using WG input from this paddle might have wrong 3-D absorption factor.

February 2, 2018
- Solved problem with replay from file batch entries.

January 25, 2018
- ​Corrected the soft clipping algorithm as after the improvement on 07.09.2017 the define limits might be exceeded in rare cases.
- Allow more clipping on paddles using corner reflection method before stopping with "Generation aborted due to excessive clipping caused by either sea state outside capability of wave maker or incorrect settings" error.

January 2, 2018
- Corrected TMA and FRF spectra when a reference depth has been specified.

November 23, 2017
- Fixed replay from file failed when a custom spectrum was apllied.

November 13, 2017
- Fixed that WAF was not applied for regular waves generated based on stream function theory.

October 6, 2017
- Added posibility to use SW generation for cases that are not shallow water which requires dispersion correction and depth averaged velocity input. Two checkboxes has been added to enable or disable these two corrections.
- Fixed that enabling/disabling absorption during generation might lead to an access violation.
- Fixed that absorption could be enabled during a test even if wave gauge quality check was not passed at start of test.

September 8, 2017
- Implemented a feature to check for updates (requires internet access).

September 7, 2017
- Updated the soft-clipping algorithm to avoid out of phase movements when acceleration limit is low.
- Changed confirmation dialogue in file conversion dialogue (when many files has been selected).

August 11, 2017
- When corner reflection is not working optimally it was previously automatically deactivated. Now a warning is given so user can continue with corner reflection if wanted. 

June 16, 2017
- Fixed corrupted button captions in calculator (only Win64 version affected).

May 10, 2017
- Added beta version of full 3D active absorption (enabled and configured in preferences dialogue).
- Fixed a problem with White Noise generation including 2nd order components (sometimes failed to show a warning if fitting of 2nd order filter was unsuccessful).
- Updated development suite to newest version which solves some high DPI issues.

March 1, 2017
- Fixed that online analysis for regular waves showed wave period equal to zero under some circumstances.

February 16, 2017
- First official release of AwaSys7.
- Transfer to new development suite able to build both 32 and 64 bit AwaSys versions. The advantage of the 64 bit application is that it is not limited to 2 Gb of memory usage (for long InvFFT tests in facilities with many paddles) and that it is slightly faster. Both version are significantly faster (1.5 to 2 times) than AwaSys6 due to a more sophisticated compilers that make heavy use of SSE instructions.
- New default skin and new logo.
- Suport for high dpi monitors (4k) with windows large font settings.
- Second order waves supported for oblique and short-crested waves.
- Second order super harmonics supported for bulls eye wave.
- Improved accuracy of 2nd order transfer function calculation for irregular waves for non-piston wavemakers and especially in deep water.
- Calculation of 2nd order control signal now uses all cpu cores and is thus much faster (on a six core PC AwaSys7 is app. 10 times faster than AwaSys6 for this caculation).
- Added support to scale spectrum after second order correction to have specified total energy.
- Give warning when a test generated with InvFFT needs so much memory that swapping would be required.
- Allow user to specify InvFFT length that are not power of 2.
- Optimizations in preference dialogue to allow to specify coordinates of each paddle and sidewall reflectors. This allow for first actuator not being half paddle width from the wall as well as using corner reflection only in one end of the wavemaker.
- Optimized quality of stream function regular waves with simoultaneous corner reflection.
- Optimized computation cost of stream function regular wave during generation (real time requirement) very significantly.
- Support for basin configuration with wavemakers on two sides (dual face).
- Synthesis methods for composite seastates including any combination of most seastate types. Examples could be swell and wind sea generated as a combination of two irregular seas or bi-cromatic waves generated as a sum of 2 regular waves.
- Changed the user interface to define the sea state in order to provide support for composite seastates and user defined lists.
- Changed that water depth is given in model scale always (also when model scale is not unity).
- Added reference water depth, i.e. water depth where defined sea state is reproduced. Transformation of wave spectrum to paddle based on linear shoaling.
- Added in preference dialogue a wave amplification factor and wave amplification file (per frequency variation) in case a very accurate match of wave height / spectral shape in reference position is demanded. This factor can correct for energy losses due to leakage around paddle faces, wave breaking, shoaling deviating from 1st order as described in above bullet, etc.
- Possibility to apply user defined spreading functions (both frequency independent and dependent).
- Added new DAQ manufacturer for Ethernet communication with VTI controllers.
- Fix errors with batches including replay from file tests.
- Changed data files to binary and in main menu->tools a binary/ascii conversion utility is available.
- Optimized reading time of replay files for preview in GUI. Together with the change to binary files this operation is now approximately 10 times faster.
- Added Torsethaugen double peak wave spectrum. A possibility has been provided to split the spectrum into its individual sea systems (swell and wind sea as represented by two Generalised Γ spectra). This makes it possible to specify main direction and directional spreading for swell and wind sea individually.
- Added Generalised Γ wave spectrum.
- Added Top-Hat wave spectrum.
- Added Gaussian Swell wave spectrum.
- Fix that Mitsuyasu spreading parameter cannot attain very high values.
- Added automatic option for White Noise Filter Length.
- Added project and test description fields to main form. These parameters are saved to header of output files.
- Added WaveLab header to wave gauge (awg) and modified demand (awd) output files.
- Added channel description field for primary and secondary input channels.
- Automatically change Windows power plan to High Performance upon start generation. Reset to user value when generation finishes.
- Changed that transfer function for combined mode wavemaker is given 1 m above hinge (as for other hinged wavemakers).
- Collected all test warnings in one dialogue.
- Added checkboxes in calibrate wave gauges dialgoue result table. In this way individual channels might be deselected for calibration (for example secondary channels that are not wave gauges).
- Added warning in calibrate wave gauge dialogue in case measured calibration coefficient deviate significantly from previous one.
- When replay from file added possibility to store awg and awd files in different file name than replay file.
- Added WG electronics delay in preference dialogue.
- Added serial key protection.
- Fix of a few smaller bugs.

Change log for AwaSys 6

 July 2, 2015
- Optimized NI Multi Value output (do not use auto start) as otherwise for some cards / driver versions time consumption of sending data was too large.

 June 17, 2015
- Solve that fail to store WG data when no primary channels defined.
- Solve that fail to start White Noise generation when active absorption system was set to 2 gauges in the farfield or when no wave gauges were defined.

June 16, 2015
- Solved problem with locked paddles sometimes giving error during manual signal or displacement between paddles clipping.

May 20, 2015
- Solved problem with solitary wave generation (failed to set wave height in some cases)

March 20, 2015
- Give more information when generation is aborted due to faulty gauge (which gauge and which problem).

March 16, 2015
- Fixed rare memory error in InvFFT (introduced in version 08.12.2014). 

Februar 25, 2015
- Solved second order theory giving very large control signals for very deep water waves.

Februar 04, 2015
- Improved calculation of nearfield for 2nd order irregular wave generation (for better simoultaneous active absorption).

- Solved that awg files were not syncronized with aws and awd file in regular and solitary waves.
- Fixed a few problems with custom time series. 
- On startup and import settings check that settings are valid.

December 08, 2014
- Reset sample time to previous value when changing away from SW (for SW sample time is automatically adjusted to small value).
- Added paddle position time series output for selected paddle in 3-D mode.
- Added runtime checks on WG signal quality. If a faulty WG is detected then if absorption is enabled abort generation with error otherwise do not allow user to enable absorption.
- If excessively exceeding clipping limits (stroke and velocity) abort generation with error "sea state outside capability of wavemaker or wrong settings".
- Various optimizations to deal with basins with several hundreds of wave generator elements.
- Result table in wave gauge calib dialog changed to have gauges in rows instead of in columns (better overview and much faster for many gauges).
- Reduced preparation time by app. 30% in typical situations.
- Changed that WG check is now performed throughout the entire preparation process, but minimum 1.5s as used before (running in separate thread).
- Absorption filter performance slightly improved with the cost of longer computational time. However, filter is now not refitted in successive tests using the same filter parameters.
- Fast calculation of absorption performance when only changing the amplification coefficient.
- Reduced memory consumption for irregular wave preparation and generation routines (typically a factor 2 to 4) to deal with basins with several hundreds of wavemakers.
- Status window to show progress of generation initialization and ability to abort in that phase.
- When filling buffer first time check CPU consumption and do not start generation if cpu consumption is too high and recommend instead to generate a replay file.
- Added random complex spectrum generation method (we though recommend filtered white noise as non-deterministic method).
- In flume configuration with wavemakers in both ends will be shown the theoretical reflection coefficient of the paddle in addition to the actual one.
- During batch mode use all non-permanent settings from replay file. This allow for more changes in preferences to be made in batch list entries (Filter lengths, InvFFTLength, more Absorption parameters, etc.).
- Added administrator password to preference settings that are usually permanent (e.g. to prevent students or other less experienced users to modify configuration).
- Added automatic option for InvFFT length, Biesel filter length and elevation input buffer length.
- Skip beginning of test where the signal is ramped up for online analysis (tapering time).
- Quick stop now respect maximum acceleration set in preferences.
- On ok click in calib wave gauges dialog check if a large offset error is present (water level not restored after calibration).
- Changed self-test wave period suggestion so it is never higher than 2 s. Changed wave height suggestion so it never saturate the stroke.
- Various improvements with respect to batch operation.
- Fixed replay files with generation of SW waves (solitary, single waves, N-waves, custom long wave profile). Fixed long time series with custom SW waves not having equal min. and max. stroke.
- Solved preference dialog sometimes giving "Not a valid board" when a NI chassis is present.
- Few smaller fixes.

May 02, 2014
- Solved problem that Rs232 VTI output manufacture had lower timing quality that others.
- Included Rs232 VTI input manufacure (VTI controller streams WG and feedback signals to AwaSys PC)
- Few minor GUI bug fixes

March 26, 2014 
- Replaced the simple Funke and Miles corner reflection with the significantly better Dalrymple corner reflection for all wave types. This new corner reflection has much less diffraction effects and will lead to a much more homogenous wave field in the main area of the basin for oblique waves (unidirectional and multidirectional).
- Irregular wave preparation has been further optimized so preparation time is not longer than with simple corner reflection in previous versions. Without corner reflection the preparation time is significantly smaller than before.
- Updated near-field calculation for second order regular wave generation (important for simultaneous active absorption).
- Included regular focused waves (bulls eye).
- Included single wave, N-wave and custom time series in SW tab to be able to model tsunamis which are typically much longer than given by the solitary wave theory.
- For VTI output manufacturer give error in preferences if RS232 buadrate too small for other settings. Give transmission delay in the note below RS232 settings.
- Optimized cpu and memory intensive operation of the real time thread (mainly active absorption) to lower CPU consumption and to improve timing quality
- Include possibility to abort replay file generation and previewing (validation).
- Solved graph resizing error occurring on Win XP.
- Solved batch generation with regular 2nd order and stream function waves.
- Solved batch generation with replay from file.
- Solved rare error occurring during mechanical transfer, self-test and generation.
- For wave gauges with fixed zero voltage position added possibility to calibrate using only one point and added check on water depth and wave gauge calibration at start generation with active absorption.
- Varius smaller GUI improvements and fixes.

November 14, 2013
- Solved AwaSys failed to start generation if a National Instruments chassis is present (i.e. a card without input or output channels).
- Improved timing quality (do not use MM timer for fill buffer).

September 24, 2013
- Added frequency dependent spreading according to Goda and Suzuki (1975).
- Improve timing quality significant especially on Windows Vista and Windows 7. 

September 12, 2013
- Added possibility to define secondary gauge channels as extra channels to acquire and store in .awg file (no secondary paddle channels has to be defined then).
- Improved handling of unused Data Translation cards.
- Small Improvements to the fitting of absorption filter for 1 gauge absorption system.
- Various GUI improvements.

September 6, 2013
- Changed calibration dialog to be similar to WaveLab (more than 2 points allowed).
- Possibility to disable active absorption for selected generators in preferences to be used for example if single wave gauge in basin is out of order.
- Added secondary channels for flumes/basins with generators in both ends (one end used for generation/absorption and one end used for absorption only i.e. replacing a passive absorber).

May 6, 2013
- Fixed 1-gauge absorption filters which rarely could converge to a solution with zero filter coefficients earlier.

March 18, 2013
- Added FRF spectrum and removed JONSWAP DS449 (outdated danish design code). Standard JONSWAP formulation still included.
- Solved deleting batch list entry giving error
- Timing thread always run on core 1 on multi core machine to solve problem with high performance counter not being synchronized across CPUs (
- Added extra check on timing quality during generation (individual sample distance).
- Avoid screen saver to start while running generation
- Solved not showing correct elapsed and remaining time when a generation is started before midnight and ending after midnight.

February 25, 2013
- Fixed generation of 2nd order subharmonics not working with white noise generation when no wave gauges were set-up in preferences.

February 5, 2013
- Fixed online spectrum giving incorrect overall parameters for one gauge absorption system and gauges not flush mount to the paddles.

November 28, 2012
- Fixed replay and batch mode giving error "cannot focus an invisible window" when wave gauges need calibration or water not calm.

November 20, 2012
- Fixed near-field calculation for stream function wave generation with active absorption based on gauges in the near-field.

June 7, 2012
- Batch list can be exported and imported and the order of the tests in the batch list can be modified.

February 10, 2012
- For wave basin applications has been added absorption performance curves for oblique waves.
- Solved test not finishing correctly with timer type set to "Int. High Perf. Counter"
- Highly improved timing quality of timer type "Int. High Perf. Counter". This timer type is now recommended instead of "Int. multimedia".
- Create Mechanical Transfer dialog now uses sample frequency and timer type from preferences dialog.
- Preference dialog is not blocked while calculating absorption performance (dialog is now shown immediately and faster to edit also)
- Significantly faster preparation and performance calculation of absorption filters by utilization of Glassman DFT function.
- Improve fitting of absorption filter for the 1 gauge on the paddle face system. One significant improvement is that very low frequencies improved so seiches in flumes and basins can effectively be removed also for periods larger than 20 s.
- Added digital output to for example turn on motors and gain up servo. The power up delay can be given.
- Added warning in preferences if gauge to paddle distance is too small for good absorption performance of 2-gauge system.
- Added combined piston and elevated hinge wave maker (optimal ratio between hinge and piston stroke automatically calculated for each frequency).
- Improved clipping for displacement limitations between paddles.
- Smaller user interface corrections

October 26, 2011
- Standard Borland pseudo random number generator replaced by high quality Mersenne Twister pseudo random number generator.
- Fixed corner reflection for negative directions.
- Various user interface corrections.

September 29, 2011
- Random number generator was earlier initialized with the random seed value even though white noise generation was chosen. For random seed values different from zero this would thus generate identical time series each time. This problem is now solved.
- Warning on "sample frequency too high" has been changed to "Biesel filter length too low to accurately reproduce waves". Moreover, the check has been improved in order to consider the higher Biesel filter lengths needed to accurately reproduce oblique and short-crested waves.

August 26, 2011
- Previous version increased generation preparation time significantly in some cases due to slow iteration. This iteration has been significantly improved in present version.
- Near field elevation calculations now include spurious waves from paddle discretisation as described in the technical background material.
- Paddle discretisation cause oblique components to be generated with too little amplitude especially in case of vertically hinged paddles. New version compensate for this so the amplitude of the main component is correct as described in the technical background material.
- Corrected that random seed in short crested seas are not leading to the same control signals

August 23, 2011
- Spectrum plotting for user interface improved for custom time series.
- Included near field components due to paddle discretisation to improve active absorption on wide paddles. In addition to the last change (August 19, 2011) this will improve active absorption stability in multi-directional waves.

August 19, 2011
- Correction for oblique wave components if spurious wave amplitude would be large compared to target progressive amplitude. This will minimize spurious and standing waves in front of the generator for wider paddles in multidirectional wave basins.

August 11, 2011
- Updated VTI digital communication to 15.9 bits instead of earlier used 14 bits. New version not compatible with old servo controllers before they as well are updated to new protocol.
- Corrected printing error in Schäffer (1993) transfer function for second order generation as corrected in Schäffer and Steinberg (2003) for multi-directional waves. Transfer function has been validated against plots in Schäffer and Steinberg (2003)

May 31, 2011
- Significantly improved soft clipping routine.
- Added complete 2nd order wave generation as presented by Schäffer (1993) and Schäffer (1996) for long-crested wave generation replacing a more simplified theory. Will later be extended to 3-D by inclusion of corrections to the theory as presented by Schäffer (2003)
- Improved time series preparation time for random phase 2nd order generation.
- Long wave filter length smaller than half the Biesel filter length is now accepted.

March 21, 2011
- First official release version of AwaSys 6
- Added active absorption based on wave gauges on paddle fronts including iteration method for filter coefficients.
- Added online analysis for 1 gauge active absorption system
- Added solitary wave generation
- Added corner reflection correction
- Added non-linear regular waves
- Added generation of prescribed surface elevation time series (e.g. prototype measurements)
- Improved 3-D wave generation for white noise generation mode
- Corrected initialization problem for white noise generation in some cases leading to paddle drift in the first part of a test.
- Improved long wave computation for white noise generation mode
- Changed that the longest 2nd order waves should not be generated as they would require a very large stroke (cut frequency now defined in preferences)
- Added combined generator type, i.e. rotation around a point below floor level.
- Added elevated hinge generator
- Added support for replay files generated by earlier versions of AwaSys
- Added possibility to lock paddles (by setting transfer constant = 0)
- Added self-test / self-calibration
- Added Com-port VTI DAQ manufacturer
- Inclusion of soft-clipping for stroke, velocity and acceleration limitations
- Added digital output on test start for synchronization with data acquisition equipment (configurable in preferences).
- User interface updates
- Various smaller changes


April 18, 2009
- Fixed access violation on shutdown on Vista
- Configuration moved to %APPDATA% instead of program directory
- Default work directory removed from preferences. Instead signal file locations will be defaulted to last used location. If no previous location has been used, my documents will be default
- Added import/export for settings
- Various smaller changes

May 29, 2008
- Added warning, if signal has been clipped during generation
- Fixed validation error, when disabling 2D Output detection link in preferences->Channels
- Units added to title for left-axis on spectrum-plots.
- “Wave train degree” text changed to “Amount of Wave Groupiness”
- Measure gain and delay: Added Paddle Offset voltage
- Replay stored signal: Changed check on voltage ranges to include Paddle Offset voltage
- Replay stored signal: Removed check on signal range
- Removed clip signal on calc absorption signal (total signal to be send out clipped further down the routine)
- IncludeTrailingPathDelimiter instead of PathDelim
- Added long wave computations for hinged paddles

May 8, 2008
- Signalfile validation on replay has been updated

May 6, 2008
- Transfer for hinged paddles now given at 1m above hinge, instead of at SWL

April 21, 2008
- Minor bug-fixes in measure gain & delay dialog

March 17, 2008
- Active absorption is no longer sensitive to the offset of the wave gauges

March 06, 2008
- Added custom spectra generation from file
- Error in online analysis fixed

December 10, 2007
- Fixed overload check
- Support for NI extended to single value (old way) and multi value
- Various other connect daq-board fixes/changes
- NI support for 4 types of terminal config
- Fix for tapering, which didn't work when set to 0sec
- Now ignoring empty lines in mechanical transfer file

May 7, 2007
- Several bug fixes
- TMA spectra added
- Swell spectra added
- Datatranslation daq-code only reserve used boards

July 19, 2005
- Minor user interface glitches fixed

February 24, 2005
- Wave train degree computation updated

February 22, 2005
- Tapering type changed from linear to cosine
- Wave train degree computation changed to use Gaussian distribution
- Bug fixed in Calibration of wave gauges

January 08, 2005
- Fixed problem with multithreaded rs232 communication

December 13, 2004
- Fixed problem with oversampling values lower than 5
- Added starting voltage level
- Added voltage offset level

November 29, 2004
- Added degree of wave trains for random phase generation
- 2-D absorption now calculate a mean value if more than 2 wave gauges is used
- 2-D absorption also enabled with more than paddle

October 3, 2004
- Added multithreaded parallel Rs232 communication

September 2, 2004
- Test signal dialog had been added for sinus-signal generation.
- Changing clock-frequency in test signal dialog now works
- Added option for 3D-Flap style in preferences “look & feel”

August 2, 2004
- First release version of AwaSys 5
- AwaSys 4 with 3-D wave generation added
- All features from AwaSys 4 is still supported except the physically voltage loop used to secure unwanted movement at start-up has been replaced by possible warnings.
- Separate subsystem for input and output, meaning different kind of equipment can be used.
- Batch runs support.
- Rs232 servo communication support
- Various features like: Gain down warnings, full screen support, graphically display of manual signal and more

Change log for AwaSys 4

October 27, 2003
- Added function to preferences which can help find the optimum filter length. The function is located as a button on the filter length input field.

September 29, 2003
- fixed minor problems when opening parameter files from inside AwaSys
- Strengthen the validation of sample frequency to ensure that high performance counter is activated when needed

September 26, 2003
- Automatic update of absorption filter preview fixed in preferences
- Setting to control whether sign of paddle position signal should be reversed or not when measuring gain and delay.

September 18, 2003
- Changed error message from "Sample frequency too low" to "Online analysis: Sample frequency too low (increase frequency or lower OverSampFactor)"

September 18, 2003
- Better windows xp theme support
- Swapped location of "Ok" and "Cancel" to be more conforming to the windows standard
- Added a gradient colour style
- Internal changes to handling of windows regional settings. Only noticeable change for the end user is that input and output fields no longer forces “.” to be the decimal separator.

June 2, 2003
- Replay tab has been updated to explorer-like browsing
- Signal and parameter files are registered in windows as AwaSys-files and can be opened in AwaSys from explorer
- Signal and parameter files can now be opened by dragging them from explorer into AwaSys main-screen
- Some fields will now increment/decrement by 1 when pressing /-. E.g. the from/to fields on the replay tab
- The calculator is shown if '/', '*' is pressed and depending on increment/decrement is enabled also on ' '
- When the program change the output signal under the signal generator tab the progress is shown in the status-bar (also when the program gains the signal down to zero before leaving this page or on close program)
- Start generation has changed and now is working as default-button, which mean that it will activate on press of the enter or return key
- The absorption performance curve is made thicker than the other curves to attract new users attention
- Added validation to additional settings under preferences
- Pressing enter or return when using calculator will now return the result
- Fixed validation error on fields with calculator capability
- Fixed bug in replay. Replay now work correct from any sample number (before replay was always started from beginning of file)
- Now supports daq-equipment from Measurement Computing and ICPDAS
- Various other minor fixes

May 26, 2003
- Added calculators buttons
- Fixed replay problem, which locked when trying to replay a file with a long path
- Fixed problem with print-preview of plots

May 15, 2003
- Quick stop button added

May 12, 2003
- First release for windows OS