On-line measurement-error correction device and method for inner profile of special-shaped shell

1 . An on-line measurement-error correction device for generating an inner profile of a conical-shaped part, the on-line measurement-error correction device comprising:

a fixing device, wherein

a vertical moving device is fixed at a top of the fixing device, the vertical moving device being connected with a horizontal moving device,

the horizontal moving device is connected with a distance monitoring device,

the distance monitoring device is movable vertically and horizontally under a drive of the vertical moving device and a drive of the horizontal moving device,

the distance monitoring device comprises a displacement monitoring element,

the displacement monitoring element is fixedly arranged on a fixing support,

the fixing support is hinged with an electric push rod,

the electric push rod is configured to drive the displacement monitoring element to change a monitoring direction,

the fixing support is connected with a supporting connecting rod through a ball head connecting rod, and

the supporting connecting rod and the electric push rod are both connected with the horizontal moving device to drive the displacement monitoring element to move horizontally.

2 . The on-line measurement-error correction device for generating the inner profile of the conical-shaped part according to claim 1 , wherein the vertical moving device comprises a first ball screw arranged vertically, the first ball screw is connected with a moving slider, the first ball screw is connected with a supporting plate through a cover plate, the supporting plate is arranged in parallel with the first ball screw, and the moving slider is connected with the horizontal moving device.

3 . The on-line measurement-error correction device for generating the inner profile of the conical-shaped part according to claim 2 , wherein a side part of the first ball screw is provided with a polished rod guide rail, the polished rod guide rail is arranged in parallel with the first ball screw, the polished rod guide rail is connected with the moving slider in a sliding manner, and the supporting plate is provided with a slot for enabling the horizontal moving device to pass through.

4 . A working method for the on-line measurement-error correction device for generating the inner profile of the conical-shaped part according to claim 3 comprising:

in a process of machining the conical-shaped part by a machine tool, positioning an initial monitoring position of the distance monitoring device through the vertical moving device and the horizontal moving device;

driving the conical-shaped part to rotate by the machine tool,

collecting, a distance between the displacement monitoring element and circumferential surface points of a longitudinal section on an inner surface of the conical-shaped part, by the displacement monitoring element,

then driving the displacement monitoring element to deflect and continue to collect distance values by the electric push rod, and

collecting the distance between each longitudinal section surface point on the inner surface of the conical-shaped part and the displacement monitoring element in layers; and

converting the distance values to three-dimensional coordinates of discrete points, and conducting three-dimensional reconstruction of actual machining dimension of the inner profile based on T-spline surface reconstruction under multi-point constraint.

5 . A working method for the on-line measurement-error correction device for generating the inner profile of the conical-shaped part according to claim 2 comprising:

in a process of machining the conical-shaped part by a machine tool, positioning an initial monitoring position of the distance monitoring device through the vertical moving device and the horizontal moving device;

driving the conical-shaped part to rotate by the machine tool,

collecting, a distance between the displacement monitoring element and circumferential surface points of a longitudinal section on an inner surface of the conical-shaped part, by the displacement monitoring element,

then driving the displacement monitoring element to deflect and continue to collect distance values by the electric push rod, and

collecting the distance between each longitudinal section surface point on the inner surface of the conical-shaped part and the displacement monitoring element in layers; and

converting the distance values to three-dimensional coordinates of discrete points, and conducting three-dimensional reconstruction of actual machining dimension of the inner profile based on T-spline surface reconstruction under multi-point constraint.

6 . The on-line measurement-error correction device for generating the inner profile of the conical-shaped part according to claim 1 , wherein the horizontal moving device comprises a second ball screw arranged horizontally, the second ball screw is connected with a screw slider, a screw guide rail is arranged at a side part of the second ball screw, the screw guide rail is arranged in parallel with the second ball screw, and the screw slider is connected with the screw guide rail in a sliding manner.

7 . A working method for the on-line measurement-error correction device for generating the inner profile of the conical-shaped part according to claim 6 comprising:

in a process of machining the conical-shaped part by a machine tool, positioning an initial monitoring position of the distance monitoring device through the vertical moving device and the horizontal moving device;

driving the conical-shaped part to rotate by the machine tool,

collecting, a distance between the displacement monitoring element and circumferential surface points of a longitudinal section on an inner surface of the conical-shaped part, by the displacement monitoring element,

then driving the displacement monitoring element to deflect and continue to collect distance values by the electric push rod, and

collecting the distance between each longitudinal section surface point on the inner surface of the conical-shaped part and the displacement monitoring element in layers; and

converting the distance values to three-dimensional coordinates of discrete points, and conducting three-dimensional reconstruction of actual machining dimension of the inner profile based on T-spline surface reconstruction under multi-point constraint.

8 . The on-line measurement-error correction device for generating the inner profile of the conical-shaped part according to claim 1 , wherein the fixing device comprises a bottom plate connected with the vertical moving device, a plurality of threaded adjustable supporting screws are arranged at a bottom of the bottom plate, each of the plurality of threaded adjustable supporting screws are connected with threaded adjustable supporting nuts, and the bottom plate is of a triangular structure” in order to provide appropriate antecedence basis.

9 . A working method for the on-line measurement-error correction device for generating the inner profile of the conical-shaped part according to claim 8 comprising:

in a process of machining the conical-shaped part by a machine tool, positioning an initial monitoring position of the distance monitoring device through the vertical moving device and the horizontal moving device;

driving the conical-shaped part to rotate by the machine tool,

collecting, a distance between the displacement monitoring element and circumferential surface points of a longitudinal section on an inner surface of the conical-shaped part, by the displacement monitoring element,

then driving the displacement monitoring element to deflect and continue to collect distance values by the electric push rod, and

collecting the distance between each longitudinal section surface point on the inner surface of the conical-shaped part and the displacement monitoring element in layers; and

converting the distance values to three-dimensional coordinates of discrete points, and conducting three-dimensional reconstruction of actual machining dimension of the inner profile based on T-spline surface reconstruction under multi-point constraint.

10 . A working method for the on-line measurement-error correction device for generating the inner profile of the conical-shaped part according to claim 1 comprising:

in a process of machining the conical-shaped part by a machine tool, positioning an initial monitoring position of the distance monitoring device through the vertical moving device and the horizontal moving device;

driving the conical-shaped part to rotate by the machine tool,

collecting, a distance between the displacement monitoring element and circumferential surface points of a longitudinal section on an inner surface of the conical-shaped part, by the displacement monitoring element” in order to provide appropriate antecedence basis,

then driving the displacement monitoring element to deflect and continue to collect distance values by the electric push rod, and

collecting the distance between each longitudinal section surface point on the inner surface of the conical-shaped part and the displacement monitoring element in layers; and

converting the distance values to three-dimensional coordinates of discrete points, and conducting three-dimensional reconstruction of actual machining dimension of the inner profile based on T-spline surface reconstruction under multi-point constraint.

11 . The working method according to claim 10 , wherein during the positioning, the fixing device is configured to adjust levelness, the monitoring direction of the displacement monitoring element is adjusted to be vertical to the electric push rod, and the vertical moving device and the horizontal moving device are adjusted to drive light emitted by the displacement monitoring element to coincide with an axis of the conical-shaped part, so that measurement positioning is completed.

12 . The working method according to claim 10 , wherein during three-dimensional coordinate conversion, a rotating angle of the displacement monitoring element, when a distance value between a point on a certain discrete layer and the displacement monitoring element is measured, is calculated through a moving distance of the electric push rod, and the three-dimensional coordinate conversion is carried out according to the rotating angle, so that the three-dimensional coordinates of the discrete points on a surface of the inner profile are obtained.

13 . The working method according to claim 10 , wherein after the three-dimensional reconstruction, a position error of actual measurement data is separated through an iterative closest point algorithm for error evaluation, Boolean operation is carried out on dimensions of an inner profile dimension reconstruction model under actual machining and a theoretical model to obtain an error model, and a machining program is generated for the error model for error correction.