Hydraulic cylinder monitoring
A refuse collection vehicle has various hydraulic actuators including at least one cylinder with an internal seal. A sensor is responsive to movement of the piston and sends a signal to a controller to indicate piston movement information during an associated vehicle body component movement. The controller is configured to determine a motion characteristic of the piston during a predetermined body component movement, compare the determined motion characteristic to a stored reference motion characteristic, and in response to determining that a difference between the determined motion characteristic and the reference motion characteristic is greater than a predetermined value, trigger an indication that the refuse collection vehicle is in need of service.
1 . A refuse collection vehicle, comprising:
at least one body component;
a hydraulic pump;
a hydraulic actuator in hydraulic communication with the hydraulic pump through a hydraulic valve operable to supply hydraulic power to cause the hydraulic actuator to move the at least one body component, the hydraulic actuator comprising a hydraulic cylinder containing a piston;
one or more sensors configured to generate sensor data indicative of at least one of:
positioning of the at least one body component; or
positioning of the piston of the hydraulic actuator; and
a controller communicatively coupled to the one or more sensors, the controller configured to perform operations comprising:
determining, based on the sensor data generated by the one or more sensors over a length of time during which the hydraulic valve is operated at a target position, a motion characteristic of at least one of the at least one body component or the piston of the hydraulic actuator;
comparing the determined motion characteristic to a stored reference motion characteristic; and
in response to determining that a difference between the determined motion characteristic and the stored reference motion characteristic is greater than a predetermined value, triggering an indication that the hydraulic cylinder is leaking fluid.
2 . The refuse collection vehicle of claim 1 , wherein the operations further comprise transmitting one or more control signals that drive the hydraulic valve to the target position.
3 . The refuse collection vehicle of claim 1 , wherein the sensor data is generated while the hydraulic actuator is subjected to a known load.
4 . The refuse collection vehicle of claim 1 , wherein the comparing the determined motion characteristic to the stored reference motion characteristic is performed to evaluate an amount of fluid leakage between two portions of the hydraulic cylinder.
5 . The refuse collection vehicle of claim 4 , wherein the piston of the hydraulic cylinder carries an internal cylinder seal and separates an internal cylinder volume into the two portions of the hydraulic cylinder.
6 . The refuse collection vehicle of claim 1 , wherein the one or more sensors comprise at least one of a potentiometer or an encoder.
7 . The refuse collection vehicle of claim 1 , wherein the hydraulic valve is an automated valve electrically controlled by a control signal to drive the automated valve to the target position.
8 . The refuse collection vehicle of claim 1 , wherein the sensor data is indicative of positioning of the at least one body component.
9 . The refuse collection vehicle of claim 1 , wherein the sensor data is indicative of positioning of the piston of the hydraulic actuator.
10 . The refuse collection vehicle of claim 1 , wherein the hydraulic cylinder is a lift cylinder connected to a lift arm of the refuse collection vehicle.
11 . The refuse collection vehicle of claim 1 , wherein the sensor data is generated while motion of the piston of the hydraulic cylinder is not being commanded.
12 . The refuse collection vehicle of claim 1 , wherein the target position of the hydraulic valve is in a fully open position.
13 . The refuse collection vehicle of claim 1 , wherein the target position of the hydraulic valve is a fully closed position.
14 . A method of prompting service of a hydraulic cylinder on a refuse collection vehicle comprising a hydraulic actuator and at least one body component, the method comprising:
causing a hydraulic valve to operate at a target position;
determining, based on sensor data generated by one or more sensors of the refuse collection vehicle while the hydraulic valve is operated at the target position, a motion characteristic of at least one of (i) the at least one body component or (ii) a piston of the hydraulic actuator, the one or more sensors configured to generate the sensor data indicative of at least one of:
positioning of the at least one body component; or
positioning of the piston of the hydraulic actuator;
comparing the determined motion characteristic to a stored reference characteristic to evaluate an amount of fluid leakage between two portions of the hydraulic actuator; and
in response to determining that a difference between the determined motion characteristic and the stored reference motion characteristic is greater than a predetermined value, triggering an indication that the hydraulic cylinder is leaking fluid.
15 . The method of claim 14 , wherein the sensor data is generated while the hydraulic actuator is subjected to a known load.
16 . The method of claim 14 , wherein the predetermined value corresponds to a maximum acceptable deviation, from the stored reference motion characteristic, that is determined based at least in part on:
an amount of expected working cycles of the hydraulic cylinder; and
an amount of expected risk that the amount of fluid leakage would result in unplanned downtime of the refuse collection vehicle.
17 . The method of claim 14 , wherein:
the hydraulic valve is an automated valve electrically controlled by a control signal to drive the automated valve to a determined position ranging from a fully open position and a fully closed position; and
the target position is the fully closed position.
18 . The method of claim 14 , wherein the hydraulic cylinder is a lift cylinder connected to a lift arm of the refuse collection vehicle.
19 . The method of claim 18 , wherein:
the determined motion characteristic comprises an amount of movement of the lift arm; and
comparing the determined motion characteristic to the stored reference characteristic comprises determining whether the amount of movement of the lift arm satisfies a threshold amount of movement.
20 . The method of claim 14 , wherein the sensor data is generated while motion of the piston of the hydraulic cylinder is not being commanded.