I need to design a number of digital IIR filters based upon transfer functions given in the s-domain. The filters are weighting filters (as discribed in British Standard 6841)which will be used to filter some vibration data in Excel in order to *****s against a human comfort criteria. I have applied the bilinear transform to give the transfer functions in the Z-domain, however I need to expand and simplify the equations to place them in the form below: <img src="http://www.mathhelpforum.com/math-help/attachments/advanced-applied-math/6961d1214399591-digital-iir-filters-form.jpg"> Once the equations are in the above form I can get the IIR filter coefficients and implement them into my filters, however I'm not quite sure how to go about it, as my maths is not very good. Is anybody willing to help me out? The three equations are as follows; 1. <img src="http://www.mathhelpforum.com/math-help/attachments/advanced-applied-math/6960d1214399514-digital-iir-filters-1.jpg"> 2. <img src="http://www.mathhelpforum.com/math-help/attachments/advanced-applied-math/6962d1214399598-digital-iir-filters-2.jpg"> 3. <img src="http://www.mathhelpforum.com/math-help/attachments/advanced-applied-math/6963d1214399604-digital-iir-filters-3.jpg"> An example is given below; <img src="http://www.mathhelpforum.com/math-help/attachments/advanced-applied-math/6965d1214399718-digital-iir-filters-eg.jpg"> Any help would be very much appreciated!
