Method of controlling tool orientation and step-over distance in face milling of curvilinear surfaces

A method of performing a milling operation, the method comprising:

• positioning a contoured workpiece;
• positioning a milling tool in relation to the contoured workpiece;
• creating a machining surface profile of the contoured workpiece;
• determining a dynamic inclination angle value in response to the machining surface profile of the contoured workpiece and a set of parameters of the milling tool;
• determining a minimum surface roughness profile in response to the dynamic inclination angle value, the machining surface profile of the contoured workpiece, and a set of parameters of the milling tool;
• and
• repositioning the milling tool traveling along the contoured workpiece in response to the minimum surface roughness profile and a condition of the dynamic inclination angle value.

A method for multi-pass 4/5-axis milling comprising:

• receiving a set of cutter parameters for a milling cutter;
• evaluating a curvilinear profile of a machining surface;
• calculating an inclination angle value in response to the curvilinear profile when a first response is received in the evaluating the curvilinear profile;
• producing a feed rate command curve;
• estimating a machined surface profile and a peak-to-valley surface roughness value by:
• determining a surface position in response to the set of cutter parameters, the curvilinear profile of the machining surface, and a radius parameter of the machining surface according to:
• {
• x
• =
• r
• 
• 
• cos
• 
• 
• ϕ
• y
• =
• r
• 
• 
• sin
• 
• 
• ϕ
• wherein the set of milling cutter geometry parameters includes r as a radius and φ as a cutter angular position,
• determining a distance between the surface position and a center-point of the curvilinear profile in response to the set of cutter parameters, the curvilinear profile of the machining surface, and the radius parameter of the machining surface according to:
• OE
• =
• BE
• _
• 2
• +
• OB
• _
• 2
• =
• (
• AE
• _
• -
• AB
• _
• )
• 2
• +
• OB
• _
• 2
• wherein AB=R sin β and OB=R cos β and wherein the curvilinear profile of the workpiece surface includes R as a radius and β as an inclination angle, and
• determining a machining error value in response to the set of cutter parameters, the curvilinear profile of the machining surface, and the radius parameter of the machining surface according to:
• DE
• _
• =
• a
• o
• =
• R
• -
• OE
• =
• R
• -
• (
• AE
• _
• -
• AB
• _
• )
• 2
• +
• OB
• _
• 2
• wherein the machining error value indicates a calculated surface roughness;
• evaluating the calculated surface roughness;
• and
• adjusting a step-over value in response to the calculated surface roughness.