US 7,441,340 B2 · Surveying instrument with compensation for mechanical errors

Abstract

The invention relates to a method of operating a surveying instrument (10) placed in a orthogonal XYZ-system at (0,0,0) having a movable unit (20), said instrument defining a sight line (128) that is controllably rotatable around a first axis (50), essentially horizontal, and around a second axis (90), essentially vertical, wherein said second axis (90) may be inaccurately positioned so that it deviates from a true vertical axis, and said first axis (50) may deviate from being orthogonal to the second axis (90); the method comprising the steps of determining at least one of the following group of errors relating to the instrument and/or its location: a) a trunnion axis error T as a function of the deviation from 90 degrees between the first axis (50) and the second axis; b) a horizontal collimation error CH, being the deviation between the sight line (128) and the perpendicular angle as related to the first axis (50); and c) a total plumb error defined by components, PI and PII, being two separate angular values defining the tilt of the instrument as related to the plumb line through the same; and d) using these determined values in continuously controlling the alignment when aiming the instrument. The invention also relates to a surveying instrument for use with the method and an error compensation system for a surveying instrument.

Claims58

Dependent claims

A method of operating a surveying instrument placed in a orthogonal XYZ-system at (0,0,0) having a movable unit, said instrument defining a sight line that is controllably rotatable around a first axis, essentially horizontal, and around a second axis, essentially vertical, wherein said second axis may be inaccurately positioned so that it deviates from a true vertical axis, and said first axis may deviate from being orthogonal to the second axis;

the method comprising the steps of determining at least one of the following group of errors relating to the instrument and/or its location:
a) a trunnion axis error T as a function of the deviation from 90 degrees between the first axis and the second axis;
b) a horizontal collimation error CH, being the deviation between the sight line and the perpendicular angle as related to the first axis;
and
c) a total plumb error defined by components, PI and PII, being two separate angular values defining the tilt of the instrument as related to the plumb line through the same;
and
d) using these determined values in continuously controlling the alignment when aiming the instrument.

4 more elements

A method of operating a surveying instrument, said instrument having a movable unit that is controllably rotatable around a first axis and around a second axis, wherein said second axis may be inaccurately positioned so that it deviates from a true vertical axis, and said first axis may deviate from being orthogonal to the second axis;

the method comprising the steps of:
a) setting a horizontal reference value (RH) indicative of a desired horizontal orientation of said movable unit;
b) detecting a horizontal orientation value (Hs) indicative of a current rotational orientation around said second axis;
c) receiving a horizontal orientation correction value (HEC;
DH) indicative of a horizontal orientation deviation of said movable unit;
wherein said horizontal orientation correction value (HEC;
DH) is generated in dependence of a transverse plumb error value (PI;
P′I);
said transverse plumb error value (PI;
P′I) being dependent on said horizontal orientation of said movable unit;
and
wherein said received horizontal orientation correction value (HEC;
DH) is dependent on the vertical orientation (V) of the movable unit so as to compensate for horizontal orientation deviations that may occur as a consequence of pivoting around said first axis;
d) generating a horizontal position value (H) indicative of a current horizontal orientation of said movable unit in response to said detected horizontal orientation value (Hs) and said horizontal orientation correction value (HEC;
DH);
e) generating a horizontal error value (eH) in dependence on said horizontal position value (H) and said horizontal reference value (RH);
f) automatically controlling the horizontal orientation of the movable unit in dependence of said horizontal error value (eH).

14 more elements

A method of operating a surveying instrument having a movable unit that is controllably rotatable around a first axis and around a second axis, wherein said second axis may be inaccurately positioned so that it deviates from a true vertical axis, and said first axis may deviate from being orthogonal to the second axis;

the method comprising the steps of:
a) setting a vertical reference value (Rv) indicative of a desired vertical orientation of said movable unit;
b) detecting a vertical orientation value (Vs) indicative of a current rotational orientation around said first axis;
c) receiving a vertical orientation correction value (VEC;
DV) indicative of a vertical orientation deviation of said movable unit;
wherein
said vertical orientation correction value (VEC;
DV) is generated in dependence of a longitudinal plumb error value (PII;
P′II);
said longitudinal plumb error value (PII;
P′II) being dependent on a horizontal orientation of said movable unit;
d) generating a vertical position value (V) indicative of a current vertical orientation of said movable unit in response to said detected vertical orientation value (Vs) and said vertical orientation correction value (VEC;
DV);
e) generating a vertical error value (ev) in dependence on said vertical position value (V) and said vertical reference value (Rv);
f) automatically controlling a vertical orientation of the movable unit in dependence of said vertical error value (ev).

12 more elements

A surveying instrument having a movable unit that is controllably rotatable around a first axis and around a second axis, wherein said second axis may be inaccurately positioned so that it deviates from a true vertical axis, and said first axis may deviate from being orthogonal to the second axis;

the surveying instrument further comprising:
means for generating a transverse plumb error value (PI;
P′I);
said transverse plumb error value (PI;
P′I) being dependent on said horizontal orientation of said movable unit;
a horizontal error corrector (412) adapted to generate a horizontal orientation correction value (HEC;
DH) in dependence of a vertical position value (V) and said transverse plumb error value (PI;
P′I);
wherein said vertical position value (V) is indicative of a vertical orientation of said movable unit;
and
a controller having:
a) an input for receiving a horizontal reference value (RH) indicative of a desired horizontal orientation of said movable unit;
b) a sensor for detecting a horizontal orientation value (Hs) indicative of a current rotational orientation around said second axis;
c) an input for receiving said horizontal orientation correction value (HEC;
DH) indicative of a horizontal orientation deviation of said movable unit;
and
d) a horizontal position generator adapted to generate a horizontal position value (H) indicative of a current horizontal orientation of said movable unit in response to said detected horizontal orientation value (Hs) and said horizontal orientation correction value (HEC;
DH);
and
e) means for generating a horizontal error value (eH) in dependence on said horizontal position value (H) and said horizontal reference value (RH);
wherein
f) said controller is adapted to automatically control the horizontal orientation of the movable unit in dependence of said horizontal error value (eH).

19 more elements

A surveying instrument (having a movable unit that is controllably rotatable around a first axis and around a second axis, wherein said second axis may be inaccurately positioned so that it deviates from a true vertical axis, and said first axis may deviate from being orthogonal to the second axis;

the surveying instrument comprising:
means for generating a longitudinal plumb error value (PII;
P′II);
said longitudinal plumb error value (PII;
P′II) being dependent on said horizontal orientation of said movable unit;
a vertical error corrector adapted to generate a vertical error correction value (VEC) in dependence of said longitudinal plumb error value (PII;
P′II);
a controller having:
a) an input for a vertical reference value (Rv) indicative of a desired vertical orientation of said movable unit;
b) a sensor for detecting a vertical orientation value (Vs) indicative of a current rotational orientation around said first axis;
and
c) an input for receiving a vertical orientation correction value (VEC;
DV) indicative of a vertical orientation deviation of said movable unit;
wherein
said vertical orientation correction value (VEC;
DV) is generated in dependence of a longitudinal plumb error value (PII;
P′II);
said longitudinal plumb error value (PII;
P′II) being dependent on said horizontal orientation of said movable unit;
d) a vertical position generator adapted to generate a vertical position value (V) of the movable unit in dependence of said vertical error correction value (VEC) and said detected vertical orientation value (Vs);
e) means for generating a vertical error value (ev) in dependence on said vertical position value (V) and said vertical reference value (Rv);
wherein
f) said controller is adapted to automatically control a vertical orientation of the movable unit in dependence of said vertical error value (ev).

20 more elements

Dependencies are inferred from the claim text.

Surveying instrument with compensation for mechanical errors

Life of this patent

Surveying instrument with compensation for mechanical errors

Life of this patent

Abstract

Claims58