Refuse weighing system and method

A weighing system for a refuse or recycling truck, comprising:

• a lifting arm movably secured to the truck at one end and having lifting forks at an opposite end for engaging a container, the lifting arm being movable between a lower position for engaging a container, a raised position for depositing material from the container into the truck, and back to the lowered position to release the emptied container;
• a load cell incorporated into each lifting fork for detecting the load carried by the lifting fork and providing an output signal proportional to the load;
• at least one acceleration sensor on the lifting arm for sensing G level on the arm and producing an output proportional to the sensed forces;
• a processing unit connected to the load cell and acceleration sensor outputs for receiving the output signals of the load cells and acceleration sensor at least for a predetermined time period as the arm is raised and for the same time period as the arm is lowered;
• the processing unit including means for compensating the load cell output signals for acceleration forces and inclination of the lifting arm, means for calculating the dynamic gross weight carried by the lifting forks as a container is raised and means for calculating the tare weight as the same container is lowered after emptying for each set of sensor outputs, and means for calculating the net weight of material deposited into the truck from the container based on the calculated dynamic weights;
• and
• the processing unit further comprising means for receiving the accelerometer output when the lifting arm is up and stationary, means for determining whether the forks are folded or non-folded based on the detected G level, and means for producing an alarm signal to notify the driver if the forks are not folded.

A method of calculating the net weight of material deposited from a refuse or recycling container into a refuse or recycling truck, comprising the steps of:

• installing a load cell along the length of at least one lifting fork of a truck lifting arm at a location spaced rearwardly of a container contacting portion of the arm such that the load cell does not contact a container during lifting;
• providing a first series of output signals from the load cell at predetermined intervals as the lifting fork is raised with a loaded container and a second series of output signals at predetermined intervals as the fork is lowered with the emptied container;
• providing a third series of output signals from at least one angle sensing device installed on the lifting arm as the arm is raised and lowered;
• using the output signals from the angle sensing device to correct the load cell output signal for fork angle;
• calculating a first dynamic gross weight of the container and contents as the lifting fork is raised using the corrected load cell outputs from a predetermined portion of the lifting cycle;
• calculating a second dynamic tare weight of the emptied container as the lifting fork is lowered using the corrected load cell outputs from a predetermined portion of the lowering cycle;
• subtracting the second tare weight from the first gross weight to determine the net weight of material deposited in the refuse truck;
• storing the computed deposited material net weight;
• and
• repeating the procedure for each container emptied along a truck collection route.

A method of calculating the net weight of material deposited from a refuse or recycling container into a refuse or recycling truck, comprising the steps of:

• installing a load cell along the length of at least one lifting fork of a truck lifting arm;
• providing a first series of output signals from the load cell at predetermined intervals as the lifting fork is raised with a loaded container and a second series of output signals at predetermined intervals as the fork is lowered with the emptied container;
• providing a third series of output signals from at least one angle sensing device installed on the lifting arm as the arm is raised and lowered;
• using the output signals from the angle sensing device to correct the load cell output signal for fork angle;
• calculating a first dynamic gross weight of the container and contents as the lifting fork is raised using the corrected load cell outputs from a predetermined portion of the lifting cycle;
• calculating a second dynamic tare weight of the emptied container as the lifting fork is lowered using the corrected load cell outputs from a predetermined portion of the lowering cycle;
• computing the G level for each load cell output signal based on the output of the angle sensing device as that signal is taken, determining if the G level is close to 1 G, and using the load cell output signals corresponding to periods when the G level is close to 1 G to calculate the first and second dynamic weights;
• subtracting the second tare weight from the first gross weight to determine the net weight of material deposited in the refuse truck;
• storing the computed deposited material net weight;
• and
• repeating the procedure for each container emptied along a truck collection route.

A method of calculating the net weight of material deposited from a refuse or recycling container into a refuse or recycling truck, comprising the steps of:

• installing a load cell along the length of at least one lifting fork of a truck lifting arm;
• providing a first series of output signals from the load cell at predetermined intervals as the lifting fork is raised with a loaded container and a second series of output signals at predetermined intervals as the fork is lowered with the emptied container;
• providing a third series of output signals from at least one angle sensing device installed on the lifting arm as the arm is raised and lowered;
• using the output signals from the angle sensing device to correct the load cell output signal for fork angle;
• calculating a first dynamic gross weight of the container and contents as the lifting fork is raised using the corrected load cell outputs from a predetermined portion of the lifting cycle;
• calculating a second dynamic tare weight of the emptied container as the lifting fork is lowered using the corrected load cell outputs from a predetermined portion of the lowering cycle;
• subtracting the second tare weight from the first gross weight to determine the net weight of material deposited in the refuse truck;
• storing the computed deposited material net weight;
• repeating the procedure for each container emptied along a truck collection route;
• and
• detecting if the same container is raised and emptied a second time at a single collection site, determining a second net weight of material dumped from the container during a second lifting and lowering cycle if a second dump of the same container is detected, and adding the second net weight to the first mentioned net weight to determine the total weight of material dumped from the container, and storing the total weight.

A weighing system for a material collecting truck for collecting materials from containers at a plurality of collection sites, the system comprising:

• a lifting arm movably mounted on the truck at one end and having lifting forks at the opposite end for engaging a container, the lifting arm being movable in a lifting cycle between a lower position for engaging a container and a raised position for depositing material from the container into the truck, and movable in a lowering cycle from the raised position back to the lower position to release the emptied container;
• a load cell incorporated into each lifting fork for detecting load carried by the lifting fork and providing a first output signal proportional to the load;
• at least one angle sensor on the lifting arm for producing a second output signal proportional to the angle of the lifting forks;
• a processing unit connected to the load cell and angle sensor outputs for receiving a first set of first and second output signals at at least one predetermined position of the lifting arm prior to emptying a lifted container and receiving a second set of first and second sensor outputs at at least one predetermined position of the lifting arm prior to release of the emptied container;
• and
• the processing unit including means for calculating a first gross weight of the container and contents using the first set of output signals, means for calculating the tare weight of the emptied container using the second set of sensor output signals, the means for calculating the gross and tare weights comprising means for determining the G level from the angle sensor output, means for determining a weight on the lifting fork from the load cell output, and means for dividing the determined weight by the determined G level, and means for calculating the net weight of material deposited from the container into the truck by subtracting the tare weight from the gross weight.

A weighing system for a material collecting truck for collecting materials from containers at a plurality of collection sites, the system comprising:

• a lifting arm movably mounted on the truck at one end and having lifting forks at the opposite end for engaging a container, the lifting arm being movable in a lifting cycle between a lower position for engaging a container and a raised position for depositing material from the container into the truck, and movable in a lowering cycle from the raised position back to the lower position to release the emptied container;
• a load cell incorporated into each lifting fork for detecting load carried by the lifting fork and providing a first output signal proportional to the load;
• a plurality of angle sensors on the lifting arm for producing a second output signal proportional to the angle of the lifting forks, each angle sensor comprising an accelerometer;
• a processing unit connected to the load cell and angle sensor outputs for receiving a first set of first and second output signals at at least one predetermined position of the lifting arm prior to emptying a lifted container and receiving a second set of first and second sensor outputs at at least one predetermined position of the lifting arm prior to release of the emptied container;
• and
• the processing unit including means for calculating a first gross weight of the container and contents using the first set of signals, means for calculating the tare weight of the emptied container using the second set of sensor outputs, and means for calculating the net weight of material deposited from the container into the truck by subtracting the tare weight from the gross weight.

A method of calculating the net weight of material deposited from a container into a collection truck, comprising the steps of:

• installing a load cell along the length of at least one lifting fork of a truck lifting arm;
• engaging and lifting a container from the ground on the lifting arm in a lifting cycle up to a raised, inverted position to deposit material from the container into the truck;
• providing at least one first output signal from the load cell at at least one predetermined position in the lifting cycle;
• providing at least one second output signal from an angle sensing device at said one predetermined position;
• calculating a first gross weight of the container and contents using said first and second output signals;
• lowering the container from the raised, inverted position back to the ground in a lowering cycle;
• providing at least one third output signal from the load cell at at least one predetermined position in the lowering cycle;
• providing at least one fourth output signal from the angle sensing device at said predetermined position in the lowering cycle;
• calculating a second tare weight of the emptied container from the third and fourth output signals;
• the steps of calculating the first gross weight and the second tare weight each comprising determining the G level from the angle sensor output, determining a weight carried on the lifting fork from the load cell output, and dividing the determined weight by the determined G level;
• subtracting the second tare weight from the first gross weight to determine the net weight of material deposited in the truck;
• storing the computed net weight;
• and
• repeating the procedure for each container emptied along a collection route.