Lisa is a "classical Feedback Control Systems" application designed to handle typical calculations in the 's' and 't' domains. 

Following the tradition of Formulae 1 (our award-winning product), Lisa packs quite a bit of functionality with tremendous ease of use, providing a very attractive value proposition to potential users. 

Lisa supports Bode Analysis and Design, Root Locus Analysis and Design and Time analysis. Lisa provides an interactive equation editor that communicates both way with the other 3 components (bode, root locus and time) allowing tremendous flexibility of analysis and design problems. 

Lisa's main innovative feature is in its ability to graphically (and instantaneously) manipulate line approximations of transfer functions while at the same time keeping track of its real equations.

Feature set of Lisa:

Bode

 

• Line approximation for phase and magnitude plots that allows users to adjust an existing transfer function or completely design one from scratch. Line approximation nodes are draggable and can be manipulated by the user graphically while the system keeps track of its equation. Users can generate line approximation from s-domain equations and/or via user interface by adding/deleting/modifying nodes from the line approximation. This is a great feature not found anywhere else that not only has tremendous pedagogical value but also eases bode design in general.

 

• Users can add/delete real/imaginary pole(s)/zero(s).

 

• Multiple bode plots.

 

• Calculates Gain Margin, Phase Margin and Bandwidth.

 

• Imports equations from Equations panel.

 

• Exports Line approximation equations to Equations Panel.

 

Root Locus

 

• Line approximation of root locus allowing the user to drag, add or delete poles and zeros and instantly see a line approximation sketch featuring : poles, zeros, asymptotes, angles of arrival and departure, real axis points and breakaway points. 

 

• Smart auto range will automatically adjust axes on plot to make it easy to see plot features.

 

• Users can add/delete real/imaginary pole(s)/zero(s).

 

• Allows users to pick a particular K given design criteria.

 

• Calculates K, Wn, Alpha and Zeta.

 

• Imports equations from Equations panel.

 

• Exports Open loop and/or closed loop transfer functions to Equations Panel.

 

Time 

 

• Provides symbolic functions for Laplace transform and its inverse. This allows users to modify time equations and see its effect in the frequency domain or vice-versa. All calculations are done symbolically so users end up with equations instead of just simulated plots. 

 

• Calculates Time delay, Time to peak, Time to rise and Time to settle.

 

• Smart auto range will automatically adjust axes on first plot to make it easy to see plot features.

 

• Supports multiple time plots.

 

• All plots support scrolling via navigational arrows. User can also set axis values by clicking on axis (bode) or it's name (root locus and time). 

 

Equations Panel

 

• 2D display and Interactive editing of math expressions.

 

• Virtual math keypad relevant to problem domain.

 

• Reusable history buffer.

 

• Multiple Undo.

 

• Interactive Help System featuring detailed explanations for every button/function available and sample problems.

 

Lisa is an excellent program to use if you have to learn Feedback control systems or just brush up on some of the concepts. Lisa is also very useful to professionals that have to deal with Feedback control systems on a regular basis. 

You simply can not beat the value of this package on handheld devices and standard notebook/desktop computers. If your computer supports Java, Lisa will run fine on it.