Crystal Growth Software

Bugless developed a process control system for growth of optical crystals. Growth of these crystals is done in high temperature furnaces, and typically requires control of a number of parameters in response to various inputs. These include:

• linear and rotational translation of growing crystal [output](interface via ethernet to PLC motion controller)
• control of induction furnace [output]
• mass of currently growing crystal [input]
• temperature of furnace [input]

With crystal growth runs taking up to two weeks to complete, long term stability and accuracy of the application are essential. With furnace temperatures of up to 2000°C, mistakes in control could be very hazardous.

An operator uses the process control system to set the appropriate growth parameters, and the rest of the growth happens automatically. The growth is controlled by closed loop PID control.

bugless provided all aspects of this system, including design, documentation, implementation choice of platform and specifications for interfacing to external hardware.

Technical notes:

• based on Qt3
• deployed on Linux
• custom widgets, graphing
• interfacing to hardware via ethernet, serial