Laser-height adjustment device for a construction machine

• US 20040068896A1
• Filed: 11/13/2003
• Published: 04/15/2004
• Est. Priority Date: 12/07/2000
• Status: Active Grant

• Current Assignee: MOBA Mobile Automation GmbH
• Original Assignee: MOBA Mobile Automation GmbH
• Inventors: Sehr, Willibald
• Granted Patent: US 6,916,070 B2
• Time in Patent Office: Days
• US Class Current: 37/413
• CPC Class Codes: E01C 19/006 by laser or ultrasound

Abstract

A laser-regulating means for a construction machine (2) for adjusting the height of a height-adjustable machining tool (8) includes three laser measuring heads which are directed to three measuring points (50, 52, 54) being spaced from each other on a reference surface (60), and an evaluating means, which, from the output signals of the laser measuring heads and from the known geometric arrangement of the laser measuring heads as regards the machining tool (8), determines the height of the machining tool (8) relative to a reference surface (60) and, from this height and from a target height determines a control signal for a height-adjustment of the machining tool (8). The construction machine is a road finisher (2) with a height-adjustable plank (8) or a cold planer with a height-adjustable milling drum.

Claims

1. Laser-regulating means for a construction machine (2;

200) for adjusting the height of a height-adjustable machining tool (8;

206), comprising

a first laser measuring head (80), a second laser measuring head (82), and a third laser measuring head (84), which are arranged at the construction machine (2;

200), with the first laser measuring head (80) and the second laser measuring head (82) being arranged at a first angle (70) to each other, with the first laser measuring head (80) and the third laser measuring head (84) being arranged at a second angle (72) to each other, with the first angle (70) and the second angle (72) being selected such that a first measuring point (50) of the first laser measuring head (80), a second measuring point (52) of the second laser measuring head (82), and a third measuring point (54) of the third laser measuring head (84) are spaced from each other on a reference surface (60), with the first measuring point (50), the second measuring point (52), and the third measuring point (54) being arranged essentially behind each other in the direction of motion of the construction machine (29); and

an evaluating means (120), which, depending on output signals of the first laser measuring head (80), the second laser measuring head (82), and the third laser measuring head (84), determines a first distance of the first laser measuring head (80) from the reference surface (60), a second distance of the second laser measuring head (82) from the reference surface (60), and a third distance of the third laser measuring head (84) from the reference surface (60), on the basis of the determined distances and the known geometric arrangement of the first laser measuring head (80), the second laser measuring head (82), and the third laser measuring head (84) relative to the machining tool (8;

206), calculates the height of the machining tool (8;

206) relative to the reference plane (60) and, depending on the calculated height and a target height, generates a height-control signal for the machining tool (8;

206).

2. Laser-regulating means in accordance with claim 1, including a fourth laser measuring head (86) and a fifth laser measuring head (88), with the fourth laser measuring head (86) being arranged at the construction machine (2;

200) at a third angle relative to the first laser measuring head (80), with the fifth laser measuring head (88) being arranged at the construction machine (2;

200) at a fourth angle relative to the first laser measuring head, with the third angle and the fourth angle being selected such that the first measuring point (50), the second measuring point (52), the third measuring point (54), a fourth measuring point of the fourth laser measuring head (86), and a fifth measuring point of the fifth laser measuring head (88) being spaced from each other on the reference surface (60) and that the first (50), second (52), third (54), fourth and fifth measuring point lie essentially behind each other in the direction of motion of the construction machine (2;

200), with the evaluating means (120) further calculating the height of the machining tool (8;

206) depending on a fourth distance of the fourth laser measuring head (86) relative to the reference surface (60), a fifth distance of the fifth laser measuring head (88) relative to the reference surface (60), and the known geometric arrangement of the fourth laser measuring head (86) and the fifth laser measuring head (88) with respect to the machining tool (8;

206).

3. Laser-regulating means in accordance with claim 2, wherein the evaluating means (120) determines the differences of two distances each, and classifies those distances as valid, the differences of which are smaller than a limiting value.

4. Laser-regulating means in accordance with claim 1 or 2, wherein the evaluating means (120) discards one of the determined distances as invalid and does not use the same for generating the height-control signal, if the respective distance lies outside a predetermined range.

5. Laser-regulating means in accordance with claim 4, wherein the predetermined range is specified by a predetermined distance above/below a plane, with the plane being specified by the remaining distances.

6. Laser-regulating means in accordance with one of claims 1 to 5, wherein the evaluating means (120) averages the determined distances.

7. Laser-regulating means in accordance with one of claims 1 to 6, wherein the laser measuring heads (80, 82, 84, 86, 88) are adjacent to each other in spatial proximity, and are arranged essentially behind each other in the direction of motion and essentially at equal distances to the machining tool (8;

206).

8. Laser-regulating means in accordance with one of the preceding claims, wherein one of the laser measuring heads (80, 82, 84, 86, 88) is aligned with the pertaining measuring point (50, 52, 55) and the machining tool (8;

206).

9. Laser-regulating means in accordance with one of claims 1 to 7, wherein the construction machine is a road finisher (2), and the machining tool is a plank (8), which is connected to the road finisher (2) via a traction arm (10), with the laser measuring heads (80, 82, 84, 86, 88) being mounted via a mounting (32) to the traction arm (10) in a common housing (30), with the height-control signal generated by the evaluating means (120) causing an adjustment of a traction point (12) of the traction arm (10) of the plank (8).

10. Laser-regulating means in accordance with one of claims 1 to 7, wherein the construction machine is a cold planer (200) having a front (202) and a rear gear (204), at least one of which is height-adjustable, and wherein the machining tool is a mill (206), with the laser measuring heads (80, 82, 84, 86, 88) being mounted (200) in a common housing (30) via a mounting (104) to the cold planer (200), with the height-control signal generated by the evaluating means (120) causing a height-adjustment of the front (202) and/or rear gear (204).

11. Laser-regulating means in accordance with claim 9, wherein one of the laser measuring heads (80, 82, 84, 86, 88) being aligned with the pertaining measuring point (50, 52, 55) and the rear edge (20) of the plank (8).

12. Laser-regulating means in accordance with claim 10, wherein one of the laser measuring heads (80, 82, 84, 86, 88) is aligned with the pertaining measuring point (50, 52, 55) and the axis of the milling drum (206).