Spatial measurement system for agricultural applications

Patent metadata

Field	Value
Publication number	US-11592276-B2
Application number	US-202017757546-A
Country	US
Kind code	B2
Filing date	Sep 28, 2020
Priority date	Dec 19, 2019
Publication date	Feb 28, 2023
Grant date	Feb 28, 2023

Abstract

A system for obtaining spatial measurements between objects such as crops in an agricultural field. The system includes a measurement device including a motorized reel containing a wound length of measuring line, and electronic encoder with shaft rotated in opposing directions by dispensing or retrieving measuring line. A pivotably movable spring-biased tension arm maintains tension in the line when being rewound. The tension arm is responsive to changes in line tension and configured to automatically start the motor to rewind the line onto the reel based on angular position of the arm. A gear train includes a translatable shuttle gear which selectively couples the reel to the motor based on movement of the tension arm. The encoder converts rotary motion of its shaft into linear field measurements. In one implementation, the tension arm comprises an inboard arm and outboard arm with translatable pulley coupled thereto by an articulated joint.

First claim

What is claimed is:

1. A system for measuring spatial relationships between objects comprising:
a frame;
a reel rotatably mounted to the frame;
a length of a flexible measuring line wound around the reel, the reel rotatable in opposing direction to rewind or pay out the measuring line;
a measurement assembly comprising at least one fixed pulley and an encoder comprising an encoder shaft, the measuring line extending around the at least one fixed pulley and encoder shaft in operable engagement; and
a self-adjusting tension mechanism arranged between the reel and measurement assembly, the tension mechanism engaging the measuring line and movable to maintain tension on the measuring line when the measuring line is rewound onto the reel.

2. The system according to claim 1 , wherein the measurement assembly is disposed at a first end of the frame and the reel is disposed at an opposite end of the frame.

3. The system according to claim 1 , wherein the tension mechanism comprises a spring biased tension arm assembly including a translatable pulley operably engaged by the measuring line.

4. The system according to claim 3 , wherein the translatable pulley is arranged in the measuring line routing path between the reel and the at least one fixed pulley of the measurement assembly.

5. The system according to claim 3 , wherein the translatable pulley is disposed on a distal terminal end of the arm assembly and a proximal portion of the arm assembly is pivotably coupled to the frame.

6. The system according to claim 5 , wherein the proximal end of the arm assembly is coupled to the frame between a front major surface of the frame and the reel.

7. The system according to claim 3 , wherein the tension arm assembly comprises a first inboard arm coupled which is coupled to the frame and a second outboard arm pivotably coupled to the inboard arm and movable relative thereto.

8. The system according to claim 7 , wherein the translatable pulley is mounted to the outboard arm.

9. The system according to claim 3 , wherein the translatable pulley is an assembly comprising a stack of multiple pulleys, and wherein the measuring line is wound around at least two pulleys in the stack.

10. The system according to claim 3 , wherein the tension mechanism further comprises a second fixed tension pulley mounted to the frame arranged between the translatable pulley and the at least one fixed pulley of the measurement assembly in the measuring line routing path.

11. The system according to claim 10 , wherein the second fixed tension pulley of the tension mechanism is an assembly comprising a second stack of multiple pulleys, and wherein the measuring line is wound around at least two pulleys in the second stack.

12. The system according to claim 3 , wherein the tension arm assembly is angularly movable between an inward collapsed position proximate to the frame and an outward extended position distal to the frame.

13. The system according to claim 12 , further comprising a spring mounted to the arm assembly, the spring biasing the arm assembly outwards towards the extended position in a direction away from the measurement assembly.

14. The system according to claim 3 , further comprising a motor selectively coupleable to the reel and operable to rotate the reel and retrieve the measuring line.

15. The system according to claim 14 , wherein the motor is selectively coupled to the reel by a gear train comprising a shuttle gear mounted to and movable with the tension arm assembly.

16. The system according to claim 1 , wherein the measurement assembly further includes a guide member through which the measuring line passes and extends outwards beyond the frame for obtaining distance measurements.

17. The system according to claim 1 , wherein the measurement assembly further includes a second fixed pulley arranged in the measuring line routing path between the at least one fixed pulley and the guide member.

18. The system according to claim 1 , wherein the frame comprises a substantially flat plate-like body having two opposing parallel major surfaces.

19. The system according to claim 1 , wherein the reel includes a reel clutch mechanism, the reel clutch mechanism adjustable by a user to set a tension force setpoint for reel that must be overcome in order to rotate the reel and pull a length of the measuring line out from the reel.

20. The system according to claim 1 , further comprising a mounting block attached to the frame and configured to mount the frame to a portable support structure for use in measuring the spatial relationships between the objects.

21. The system according to claim 1 , further comprising a controller including a microprocessor and user interface, the controller operably and communicably coupled to the encoder for receiving measurement data from the encoder.

22. A system for measuring spatial relationships between objects comprising:
a vertical centerline;
a frame;
a reel rotatably mounted to the frame;
a length of a flexible measuring line wound around the reel, the reel rotatable in opposing direction to retrieve the measuring line or dispense the measuring line on demand;
a measurement assembly comprising at least one fixed pulley and an encoder comprising an encoder shaft, the measuring line wrapped around the at least one fixed pulley and encoder shaft in operable engagement therewith; and
a movable self-adjusting tension arm assembly arranged between the reel and measurement assembly in a measuring line routing path, the tension arm assembly comprising an inboard arm pivotably mounted to the frame and an outboard arm pivotably coupled to inboard arm at an articulated joint and movable relative thereto;
the tension arm assembly comprising a translatable pulley mounted to and movable with the outboard arm;
a fixed tension pulley cooperating with the tension arm assembly and mounted to the frame;
a first spring biasing the tension arm assembly in a direction away from the encoder;
the measuring line extending from the at least one fixed pulley of the measurement assembly to the translatable pulley or the fixed tension pulley;
wherein the tension arm assembly is movable in a plurality of positions dependent upon variations in tension of the measuring line when the measuring line is retrieved by the reel.

23. A method for maintaining tension in a distance measuring device, the method comprising:
providing a measurement device comprising a frame including a rotatable reel around which a length of a measuring line is wound, a motor comprising a motor gear selectively coupleable to a reel gear for rotating the reel, an encoder comprising an encoder shaft, and a pivotably movable spring-biased tension arm assembly;
routing the measuring line in order from the reel and operably engaging a translatable pulley mounted to the tension arm assembly, a fixed tension pulley mounted to the frame, and the encoder shaft;
moving the measurement device in a first linear direction;
applying a first tension force to the measuring line;
unwinding measuring line from the reel which rotates in a first feed direction;
rotating the tension arm assembly in a first direction towards the encoder in response to the first tension force;
moving the measurement device in a second linear direction opposite to the first linear direction which decreases the first tension force;
automatically rotating the tension arm assembly in a second direction away from the encoder via spring

Assignees

• Prec Planting Llc

Inventors

• Benckendorf Jared
• Schlipf Ben L

Classifications

• G01B5/16

  between a succession of regularly spaced objects or regularly spaced apertures · CPC title

• G01B5/0035

  Measuring of dimensions of trees · CPC title

• G01B7/026

  for measuring length of cable, band or the like, which has been paid out, e.g. from a reel (measuring length of objects while moving G01B7/04) · CPC title

• G01B3/11 Primary

  Chains for measuring length · CPC title

• G01B3/1005 Primary

  Means for controlling winding or unwinding of tapes · CPC title