Methods, systems, and apparatus for computer aided design of physical structures include: producing a quad parameterization computer model (including quad parameter domains) of a polygon mesh, where quad parameter domain(s) adjacent to a boundary curve interpolate the boundary curve; and forming a computer model of a three dimensional object by constructing locally refinable surface representation(s) from the quad parameterization computer model, refining a boundary of the locally refinable surface representation(s) to approximate the boundary curve within a first tolerance value set in accordance with a smallest dimension representable by a geometry modeling kernel, freezing control points of the locally refinable surface representation(s) at the boundary, and modifying remaining interior portions of the locally refinable surface representation(s) to approximate the polygon mesh within a second tolerance value that is at least an order of magnitude larger than the first tolerance value.

Methods, systems, and apparatus for computer aided design of physical structures include: producing a quad parameterization computer model (including quad parameter domains) of a polygon mesh, where quad parameter domain(s) adjacent to a boundary curve interpolate the boundary curve; and forming a computer model of a three dimensional object by constructing locally refinable surface representation(s) from the quad parameterization computer model, refining a boundary of the locally refinable surface representation(s) to approximate the boundary curve within a first tolerance value set in accordance with a smallest dimension representable by a geometry modeling kernel, freezing control points of the locally refinable surface representation(s) at the boundary, and modifying remaining interior portions of the locally refinable surface representation(s) to approximate the polygon mesh within a second tolerance value that is at least an order of magnitude larger than the first tolerance value.

Methods, systems, and apparatus, including medium-encoded computer program products, for computer aided design of physical structures include, in at least one aspect, a fully automatic method of converting a generative design into an editable, watertight B-Rep by leveraging the generative solver input and representation to: (1) embed the exact input solid boundary surfaces where the design coincides with the input, (2) approximate everywhere else the design boundary with globally smooth, editable “organic” surfaces, and (3) join all surfaces to form a generative design output B-Rep.

Methods, systems, and apparatus, including medium-encoded computer program products, for computer aided design of physical structures include: obtaining a first 3D model including a polygon mesh associated with one or more modelled solids, the one or more modelled solids being in a boundary representation format; producing from the polygon mesh a quad patch network that combines, using transfinite interpolation, the polygon mesh with one or more smooth boundary curves corresponding to the one or more modelled solids; defining one or more locally refinable smooth surface representations using the quad patch network as input and based at least in part on a smallest dimension representable by a geometry modeling kernel of a computer aided design program; and combining the one or more locally refinable smooth surface representations with the one or more modelled solids to form a second 3D model that is watertight at the one or more smooth boundary curves.

Methods, systems, and apparatus, including medium-encoded computer program products, for computer aided design of physical structures include: obtaining a first 3D model including a polygon mesh associated with one or more modelled solids, the one or more modelled solids being in a boundary representation format; producing from the polygon mesh a quad patch network that combines, using transfinite interpolation, the polygon mesh with one or more smooth boundary curves corresponding to the one or more modelled solids; defining one or more locally refinable smooth surface representations using the quad patch network as input and based at least in part on a smallest dimension representable by a geometry modeling kernel of a computer aided design program; and combining the one or more locally refinable smooth surface representations with the one or more modelled solids to form a second 3D model that is watertight at the one or more smooth boundary curves.

Provided is a multiple spindle machine tool which is capable of sufficiently preventing tool exchange failure due to cutting chips and improving the freedom of machine operation. A left and right magazines are provided in the tool storage chamber as an automatic tool changer corresponding to a left and right spindles. A right and left shutters, each of which is arranged to open and close as the left and right spindles enter and exit between the machining chamber and the tool storage chamber, are provided for each of the spindles.

A work piece processing device includes a tool device, a work piece holder and a servo-elastic actuator system having simultaneous precision force and position control that moves one of the tool device and the work piece holder to the other of the tool device and work piece holder. The servo-actuator system including a servo-actuator, a compliance elastic member and a weight compensation elastic member disposed in a force transmission path with the compliance elastic member and the weight compensation elastic member disposed with respect to each other so that a spring force exerted by the weight compensation elastic member is opposed to a spring force exerted by the compliance elastic member.

A work piece processing device includes a tool device, a work piece holder and a servo-elastic actuator system having simultaneous precision force and position control that moves one of the tool device and the work piece holder to the other of the tool device and work piece holder. The servo-actuator system including a servo-actuator, a compliance elastic member and a weight compensation elastic member disposed in a force transmission path with the compliance elastic member and the weight compensation elastic member disposed with respect to each other so that a spring force exerted by the weight compensation elastic member is opposed to a spring force exerted by the compliance elastic member.

The present disclosure is directed to calibrating position detection for a tool. The tool can use a sensor to detect a first value of a parameter. The tool can use a motor to extend the working member of the tool towards a working surface. The tool can include a base. The tool can detect, with the working member in contact with the working service, a second value of the parameter. The tool can determine a z-axis position of the working member relative to the working surface.

The present disclosure is directed to calibrating position detection for a tool. The tool can use a sensor to detect a first value of a parameter. The tool can use a motor to extend the working member of the tool towards a working surface. The tool can include a base. The tool can detect, with the working member in contact with the working service, a second value of the parameter. The tool can determine a z-axis position of the working member relative to the working surface.