Machine guidance system and method for defining and maintaining slope and/or cross-slope during earthmoving operations

Abstract

A system and a method for defining and maintaining slope and cross-slope parameters during construction vehicle operations are provided. Data associated with an attachment positioned at reference points on the terrain and the corresponding location and elevation information from a location sensor are obtained. Based on this data, the processing unit calculates slope and cross-slope parameters by analyzing the differences in elevation and the horizontal distances between the reference points. As a result, guidance information is generated for real-time operator feedback or for the automatic adjustment of the attachment. The system includes a location sensor (e.g., GNSS) and optical sensors (e.g., LiDAR) for calculating the slope and cross-slope values, and for controlling operation of the attachment to ensure that the grading or earthmoving matches defined specifications.

What is claimed is: 
     
         1 . A method comprising:
 positioning an attachment of a construction vehicle at a first reference point on a terrain;   obtaining, by a location sensor, first location data indicative of a first geographic position and first elevation of the first reference point;   monitoring movement of the construction vehicle away from the first reference point while measuring a horizontal distance moved and a change in elevation from the first elevation;   calculating, by a processing unit, a slope parameter based on the change in elevation and the horizontal distance moved from the first reference point;   generating, by the processing unit, guidance information indicative of adjustments required to align the attachment with the slope parameter that is calculated; and   outputting the guidance information to an operator interface for real-time feedback on adjustment of positions of the attachment or to a control system for automatic adjustment of the attachment.   
     
     
         2 . The method of  claim 1 , further comprising:
 positioning the attachment at a second reference point on the terrain; and   obtaining, by the location sensor, second location data indicative of a second geographic position and second elevation of the second reference point,   wherein the change in elevation is an elevation difference between the first reference point and the second reference point, and   wherein the horizontal distance is calculated as the horizontal distance between the first reference point and the second reference point.   
     
     
         3 . The method of  claim 2 , wherein the elevation difference of the slope parameter is a first elevation difference, and further comprising:
 calculating, by the processing unit, a cross-slope parameter based on a second elevation difference between the first reference point and the second reference point along a direction that is transverse to the horizontal distance,   wherein the guidance information generated by the processing unit also indicates the adjustments required to align the attachment with the cross-slope parameter that is calculated.   
     
     
         4 . The method of  claim 2 , wherein the slope parameter is calculated by the processing unit as a percentage grade based on the elevation difference divided by the horizontal distance between the first reference point and the second reference point. 
     
     
         5 . The method of  claim 2 , further comprising:
 automatically adjusting the positions and orientation of the attachment using actuators to align the attachment with the slope parameter that is calculated.   
     
     
         6 . The method of  claim 2 , wherein the first reference point and the second reference point are marked by the operator using physical buttons or a touchscreen interface onboard the construction vehicle. 
     
     
         7 . The method of  claim 1 , further comprising:
 detecting errors in slope alignment of the attachment during operation of the construction vehicle based on deviations from the slope parameter and providing corrective guidance to the operator.   
     
     
         8 . A machine guidance system comprising:
 a location sensor configured to obtain geographic position and elevation data for at least two reference points on a terrain while onboard a construction vehicle; and   a processing unit electrically coupled to the location sensor and configured to calculate a slope parameter based on an elevation difference and horizontal distance between the at least two reference points, the processing unit configured to generate guidance information indicative of adjustments required to align an attachment of the construction vehicle with the slope parameter that is calculated, the processing unit configured to output the guidance information to an operator interface or a control system.   
     
     
         9 . The machine guidance system of  claim 8 , further comprising:
 the operator interface configured to display the guidance information to an operator in real time for guiding operation of the attachment of the construction vehicle.   
     
     
         10 . The machine guidance system of  claim 8 , further comprising:
 the control system configured to automatically adjust the position and orientation of the attachment based on the guidance information.   
     
     
         11 . The machine guidance system of  claim 8 , wherein the processing unit is configured to calculate a cross-slope parameter based on another elevation difference perpendicular to the horizontal distance, the processing unit configured to generate the guidance information with the slope parameter and the cross-slope parameter that are calculated. 
     
     
         12 . The machine guidance system of  claim 11 , wherein the processing unit is configured to calculate the cross-slope parameter by analyzing elevation differences across multiple points perpendicular to the horizontal distance. 
     
     
         13 . The machine guidance system of  claim 11 , wherein the processing unit is configured to calculate the slope parameter is calculated as a percentage grade based on the elevation difference divided by the horizontal distance between the at least two reference points. 
     
     
         14 . The machine guidance system of  claim 8 , wherein the location sensor is configured to mark at least two reference points responsive to an operator using physical buttons or a touchscreen interface onboard the construction vehicle. 
     
     
         15 . The machine guidance system of  claim 8 , wherein the processing unit is configured to detect errors in slope alignment of the attachment during operation of the construction vehicle based on deviations from the slope parameter and provide corrective guidance to the operator. 
     
     
         16 . A method comprising:
 positioning a bucket of a construction vehicle at a first reference point on a terrain;   obtaining, by a location sensor, first location data indicative of a first geographic position and first elevation of the first reference point;   positioning the bucket at a second reference point on the terrain;   obtaining, by the location sensor, second location data indicative of a second geographic position and second elevation of the second reference point;   calculating, by a processing unit, a slope parameter along a slope direction based on a first elevation difference and a horizontal distance between the first reference point and the second reference point;   calculating, by the processing unit, a cross-slope parameter based on a second elevation difference perpendicular to the slope direction;   generating, by the processing unit, guidance information indicative of adjustments required to align the bucket with the slope parameter and the cross-slope parameter that are calculated; and   outputting the guidance information to an operator interface for real-time feedback on adjustment of positions of the bucket or to a control system for automatic adjustment of the bucket.   
     
     
         17 . The method of  claim 16 , wherein the cross-slope parameter is calculated by analyzing multiple ones of the second elevation difference across multiple points perpendicular to the slope direction. 
     
     
         18 . The method of  claim 16 , wherein the slope parameter is calculated by the processing unit as a percentage grade based on the first elevation difference divided by the horizontal distance between the first reference point and the second reference point. 
     
     
         19 . The method of  claim 16 , further comprising:
 automatically adjusting the positions and orientation of the bucket using actuators to align the bucket with the slope parameter and the cross-slope parameter that are calculated.   
     
     
         20 . The method of  claim 16 , further comprising:
 detecting errors in slope alignment of the bucket during operation of the construction vehicle based on deviations from one or both the slope parameter or the cross-slope parameter, and providing corrective guidance to the operator.