Autonomous backfilling apparatus

Abstract

A backfilling sensor system for trench reinstatement. The system is mounted on a wheeled or tracked chassis and supports a fill material mixer above a hopper. The system may include a sensor in front of the hopper in a path of travel to make steering corrections due to deviations in the trench path. The system may further include a sensor behind the hopper to examine fill level and make speed adjustments to increase or decrease the fill level. Finally, a sensor above the hopper may cooperate with the other sensors to maintain the fill material level in the hopper such that the flow rate into the trench is maintained, slowed or increased. A controller may communicate with each sensor to direct changes to speed and direction of the system and adjust a flow rate from the mixer by, for example, raising or lowering a gate.

1 . A method comprising:
 uncovering a trench with a microtrencher;   following the trench with a trench filling machine containing a fill material;   at a first location on the trench filling machine, detecting a path of the trench and sending a first signal to a processor;   at a second location on the trench filling machine, detecting a level of the fill material in a hopper and sending a second signal to a processor;   at a third location on the trench filling machine, detecting level of fill material in the trench and sending a third signal to the processor; and   in response to the first signal, the second signal, and the third signal, adjusting a speed and orientation of the trench filling machine.   
     
     
         2 . The method of  claim 1  further comprising:
 in response to the second signal, changing a flow rate of the fill material into the hopper. 
 
     
     
         3 . The method of  claim 1  further comprising:
 in response to the second signal and the third signal, changing a flow rate of the material into the hopper. 
 
     
     
         4 . The method of  claim 1  wherein the first sensor comprises a LiDAR sensor. 
     
     
         5 . The method of  claim 1  further comprising:
 in response to the first signal, the second signal, and the third signal, illuminating a visual indicator when a speed and orientation adjustment is required. 
 
     
     
         6 . The method of  claim 1  wherein the step of adjusting the speed and orientation of the trench filling machine is performed automatically by the processor. 
     
     
         7 . A trench filling apparatus, comprising:
 a frame;   a motive force member supporting the frame;   a fill material container supported by the frame;   a hopper supported by the frame, the hopper having an upward-facing opening and a surface engaging member, wherein a slot is formed in the surface engaging member;   a first sensor disposed on a first side of the slot;   a second sensor disposed on a second side of the slot;   a third sensor disposed above the upward-facing opening; and   a processor configured to receive a first signal from the first sensor, a second signal from the second sensor, and a third signal from the third sensor.   
     
     
         8 . The trench filling apparatus of  claim 7  in which the first sensor is a LiDAR sensor. 
     
     
         9 . The trench filling apparatus of  claim 7  wherein the fill material container defines a door disposed on the fill material container above the upward-facing opening of the hopper. 
     
     
         10 . The trench filling apparatus of  claim 9  further comprising a gate, wherein the gate is disposed over the door. 
     
     
         11 . The trench filling apparatus of  claim 10  wherein the processor is configured to adjust the gate in response to the third signal. 
     
     
         12 . The trench filling apparatus of  claim 11  wherein:
 the processor is configured to adjust a direction of the motive force member in response to the first signal; and 
 the processor is configured to adjust a speed of the motive force member in response to the second signal. 
 
     
     
         13 . The trench filling apparatus of  claim 7  wherein the processor is configured to adjust a direction of the motive force member in response to the first signal. 
     
     
         14 . The trench filling apparatus of  claim 7  wherein the processor is configured to adjust a speed of the motive force member in response to the second signal. 
     
     
         15 . The trench filling apparatus of  claim 7  wherein the processor is configured to adjust a speed and orientation of the motive force member in response to each of the first sensor, second sensor, and third sensor.