Multi-Axis Wave Generator

Our client are developers and manufacturers of innovative products and environmentally sensitive systems for generating power from marine environments. One of the products they manufacture collects wave data from the sea.

The task was to create a wave simulator so that wave patterns could be manipulated so that measurement data could be checked for accuracy using the same wave data information. 

2M designed a simple single axis servomotor control system. The servomotor controls a winch for a line which, through a set of pulleys, is attached to the data collecting device. The control system then creates different wave patterns that the device can then measure.  

The first part of the project was to create a simple sinewave so our client could change

• the amplitude and
• period of the wave.

This was then used as a control. 

A Sine Wave aka "sinusoidal sine wave" / "sinusoidal waveform" is a smooth, periodic oscillation that describes a repeating pattern in space or time.

They are used in electrical engineering to analyze the frequency and/or phase response of a linear electrical system over a specific frequency range.

Now it was time to create random waves that simulate an Ocean Wave.

Several fixed random cam profiles were created in the controller from real ocean wave data that the client provided.

A cam is a rotating machine element that transforms rotational energy into a specific, controlled movement in another component called the follower.

This enabled 2M to develop different algorithms to allow the operator to randomly select to run any of the different wave patterns.

They could also

• manipulate the base wave by changing the amplitude and period, similar to the sinewave, and also
• change the sequence of these randomized waveforms. 

In summary, based on the selected cam profile, the control system also sampled the real position of the device using the feedback position of the servomotor encoder and produced data which the client can download and compare with the device's recorded data. 

In reality, it was found that an ocean wave is made up of two or more waves with a main wave as the carrier and smaller wave patterns sitting on top of it.

2M developed software inside the Controller with the recorded real-time data collated by the client and their software tools. This is then loaded onto a CAM generator which produces the motion profile required. The generated file is also saved for retrieval later. 

Based on the solutions above, the client was able to demonstrate that the device was able to pick-up the secondary waveform that was injected into the wave pattern. This then created another real-life challenge that the device will experience at Sea. It will tilt for specific degrees in strong ocean waves and the client needed to measure this as well.

As such, the R&D project then expanded into a Multi-Axis Wave Generator.