Tool wear model is presented by firstly extracting power signal eigenvalue through tool wear analysis of special spiral rod milling,and then establishing the mapping between the signal eignevalue and the tool wear value.

The effect of tool wear and breakage on the feature of power signal in time and frequency domain is studied based on a large amount of experiments, and it is indicated that there is a good relationship between tool condition and power consumption or magnitude at the spindle rotation frequency.

The acoustic emission signal and the power signal of grinding wheel motor will change when wheel is dulled or broken in grinding process.

After software simulation,we find that the algorithm is not only easy to be realized,but also efficient to help detect the period of useful signal even when the noise power is larger than periodic signal power.

The factors to influence the signal power, such as the size of target, the parameters of water and the angles of incidence etc.

This paper introduces the successful application of digital synthesis technique to three phase precision power signal source.