Abstract: A plurality of representative points are selected from a group of points obtained as results of shape measurement of an object, respective principal curvatures are calculated at the representative points on the basis of positional relationships between the representative point and a plurality of points existing around the representative point, a line of curvature is created on the basis of the principal curvatures of the representative points and a curved surface is generated using this line of curvature.

Abstract: A computer aided design system and a computer aided design program which can greatly increase the utility of a computer aided design model, and can improve the efficiency of design and production processes, by adopting a curved surface theory which ensures the continuity of a free-form line or surface. A computer executes: a point sequence information extraction process for extracting a plurality of point sequences on a curved surface; a dividing process for generating a curved surface from the point sequences and dividing the curved surface into a predetermined number of mesh points; a first fundamental form computing process for computing coefficients of the first fundamental form; a second fundamental form computing process for computing coefficients of the second fundamental form; and a storage process for storing the point sequence information, the coefficients of the first fundamental form and the coefficients of the second fundamental form.

Abstract: A plurality of representative points are selected from a group of points obtained as results of shape measurement of an object, respective principal curvatures are calculated at the representative points on the basis of positional relationships between the representative point and a plurality of points existing around the representative point, a line of curvature is created on the basis of the principal curvatures of the representative points and a curved surface is generated using this line of curvature.

Abstract: There is provided a computer aided design system and a computer aided design program which can greatly increase the utility value of a computer aided design model, and can improve the efficiency of design and production processes, by adopting a curved surface theory which ensures the continuity of a free-form line/free-form surface.

Abstract: A method for determining a heating line for bending a steel plate includes the steps of: placing a virtual pattern on a virtual plate; rolling the plate along a frame line from a reference position to contact the plate at two points on the plate; rolling the steel plate back to the reference position; obtaining straight lines connecting the contact points; determining a heating point relative to a reference point; repeating the same steps while contacting the contact points on a reference point side; drawing straight lines from a certain heating point on a certain line to heating points on other lines; examining the degree of parallelism between each straight line and a roller line; grouping the relevant heating points as the same group; and connecting the heating points of the same group by a straight line or a curve.

Abstract: A method for determining a heating line for bending a steel plate includes the steps of: placing a virtual pattern on a virtual plate; rolling the plate along a frame line from a reference position to contact the plate at two points on the plate; rolling the steel plate back to the reference position; obtaining straight lines connecting the contact points; determining a heating point relative to a reference point; repeating the same steps while contacting the contact points on a reference point side; drawing straight lines from a certain heating point on a certain line to heating points on other lines; examining the degree of parallelism between each straight line and a roller line; grouping the relevant heating points as the same group; and connecting the heating points of the same group by a straight line or a curve.

Abstract: A method and a system for determining a heating point and a heating line in steel plate bending place a virtual wooden pattern on a virtual steel plate; roll the wooden pattern or steel plate along a frame line from a reference position to contact the wooden pattern and steel plate at two points A, B on the steel plate and C, D on the wooden pattern; roll the wooden pattern or steel plate in the reverse direction for return to the reference position; obtain straight lines U, V connecting the contact points A, B and C, D, respectively; determine a heating point relative to a reference point based on an intersection point of the straight lines U, V; repeat the same steps while contacting the contact points A, C on a reference point side to use their contact point as a new reference point, to determine respective heating points along a specific line up to the end of the steel plate; draw straight lines from a certain heating point on a certain line to heating points on other lines based on the determined heating

Abstract: A method and a system for determining a heating point and a heating line in steel plate bending place a virtual wooden pattern on a virtual steel plate; roll the wooden pattern or steel plate along a frame line from a reference position to contact the wooden pattern and steel plate at two points A, B on the steel plate and C, D on the wooden pattern; roll the wooden pattern or steel plate in the reverse direction for return to the reference position; obtain straight lines U, V connecting the contact points A, B and C, D, respectively; determine a heating point relative to a reference point based on an intersection point of the straight lines U, V; repeat the same steps while contacting the contact points A, C on a reference point side to use their contact point as a new reference point, to determine respective heating points along a specific line up to the end of the steel plate; draw straight lines from a certain heating point on a certain line to heating points on other lines based on the determined heating

Abstract: A method and a system for determining a heating point and a heating line in steel plate bending place a virtual wooden pattern on a virtual steel plate; roll the wooden pattern or steel plate along a frame line from a reference position to contact the wooden pattern and steel plate at two points A, B on the steel plate and C, D on the wooden pattern; roll the wooden pattern or steel plate in the reverse direction for return to the reference position; obtain straight lines U, V connecting the contact points A, B and C, D, respectively; determine a heating point relative to a reference point based on an intersection point of the straight lines U, V; repeat the same steps while contacting the contact points A, C on a reference point side to use their contact point as a new reference point, to determine respective heating points along a specific line up to the end of the steel plate; draw straight lines from a certain heating point on a certain line to heating points on other lines based on the determined heating

Abstract: An automatic plate bending system using high frequency induction heating has many universal poles for bearing a steel plate, a member to be heated, by supporting it from below, the height positions of front end portions of the universal poles themselves being adjustable, and automatically moves a high frequency heating coil of a high frequency heating head above the steel plate, which is placed on the universal poles, along predetermined heating lines while retaining a constant clearance between the high frequency heating coil and the surface of the steel plate, whereby the steel plate is heated and automatically bent into a desired shape.

Abstract: An automatic plate bending system using high frequency induction heating has many universal poles for bearing a steel plate, a member to be heated, by supporting it from below, the height positions of front end portions of the universal poles themselves being adjustable, and automatically moves a high frequency heating coil of a high frequency heating head above the steel plate, which is placed on the universal poles, along predetermined heating lines while retaining a constant clearance between the high frequency heating coil and the surface of the steel plate, whereby the steel plate is heated and automatically bent into a desired shape.