Systems and methods for controlling agricultural harvesting header height
A system that provides proactive control of header height, or an associated fluid pressure for a fluid used in positioning of the height of the header. The system can to maintain a generally constant header height as an agricultural vehicle performs an operation along a field. The system can use a model of either or both mechanical or hydraulic systems of the header. The model can receive information from a terrain map, as well as information that is outputted from header sensors. A predicted output generated by the model can be compared to desired header height settings to derive an error computation. An optimizer can use the error computation, a cost function, and constraints to derive a predicted input. The predicted input can both be communicated to the model as a feedback signal and include one or more control signals for an operation of one or more actuators of the header.
1 . A system for adjusting an actual height of a header of an agricultural vehicle, the system comprising:
at least one sensor configured to provide a sensor output indicative of at least one of the actual height of the header and an actual fluid pressure of a fluid used in the adjustment of the actual height of the header;
a communication unit adapted to receive a terrain map;
at least one actuator configured to adjust the actual height of the header;
at least one processor; and
a memory device coupled to the at least one processor, the memory device including instructions that when executed by the at least one processor cause the at least one processor to:
identify, from the terrain map, one or more variations in a terrain of a field;
generate, using a header model and based at least in part on the one or more variations in the terrain of the field and the sensor output, a predicted output comprising at least one of (1) a predicted header height, when the sensor output is indicative of the actual height of the header, to attain a preselected header height, and (2) a predicted fluid pressure, when the sensor output is indicative of the fluid pressure of the fluid, to attain a preselected fluid pressure for the header when the header or agricultural vehicle will be at a location in the field that corresponds to the one or more variations in the terrain of the field;
determine an error computation based on a difference between at least one of (1) the predicted header height and the preselected header height, and (2) the predicted fluid pressure and the preselected fluid pressure;
generate a predicted input based, at least in part, on the error computation and a cost function evaluated over a period of time, the predicted input comprising at least one of a model header height and a model fluid pressure, wherein the cost function is subject to a plurality of constraints in a hierarchical arrangement, such that satisfaction of a higher-priority constraint of the plurality of constraints is prioritized regardless of whether such satisfaction causes a lower-priority constraint of the plurality of constraints to not be satisfied; and
generate, based on the predicted input and before the header or the agricultural vehicle reaches the identified one or more variations in the terrain, one or more control signals for the at least one actuator to adjust the actual height of the header.
2 . The system of claim 1 , wherein the cost function is at least a function of a difference between at least one of, when the sensor output is indicative of the actual height of the header and the predicted header height, and, when the sensor output is indicative of the fluid pressure of the fluid, the actual fluid pressure and the predicted fluid pressure.
3 . The system of claim 1 , wherein the memory device further includes instructions that when executed by the at least one processor cause the at least one processor to proactively generate the one or more control signals for the at least one actuator to adjust the actual height of the header before the header or the agricultural vehicle reaches the location in the field that corresponds to the one or more variations in the terrain.
4 . The system of claim 1 , wherein the memory device further includes instructions that when executed by the at least one processor cause the at least one processor to communicate at least a portion of the predicted input to the header model as a feedback signal.
5 . The system of claim 4 , wherein the memory device further includes instructions that when executed by the at least one processor cause the at least one processor to adjust the header model in response to the feedback signal.
6 . The system of claim 1 , wherein the memory device further includes instructions that when executed by the at least one processor cause the at least one processor to receive a signal indicative of an operator defining at least one constraint of the plurality of constraints.
7 . The system of claim 1 , wherein the plurality of constraints comprises at least an energy constraint that limits an energy consumption of the at least one actuator and a speed constraint that limits a speed or an acceleration for a displacement of the header.
8 . The system of claim 1 , wherein the plurality of constraints comprises at least one of an energy constraint that limits an energy consumption of the at least one actuator and a speed constraint that limits a speed or an acceleration for a displacement of the header.
9 . The system of claim 1 , wherein the header model comprises one or more models of at least one of a mechanical system for when the predicted output is the predicted header height, and a hydraulic system of the header for when the predicted output is the predicted fluid pressure.
10 . The system of claim 9 , wherein the header model further comprises one or more parameters obtained from one or more datasheets or one or more lookup tables.
11 . The system of claim 10 , wherein the one or more parameters includes an estimated parameter obtained from one or more measurements taken from the header.
12 . A method for adjusting an actual height of a header of an agricultural vehicle, the method comprising:
identifying, from a terrain map, one or more variations in a terrain of a field;
generating, using a header model and based at least in part on the one or more variations in the terrain of the field and a sensor output from one or more sensors indicative of at least one of the actual height of the header or an actual fluid pressure of a fluid used by at least a cylinder to position the header at the actual height, a predicted output comprising at least one of (1) a predicted header height, when the sensor output is indicative of the actual height of the header, to attain a preselected header height, and (2) a predicted fluid pressure to attain a preselected fluid pressure, when the sensor output is indicative of the fluid pressure of the fluid, for the header when the header or agricultural vehicle is estimated to be at a location in the field that corresponds to the one or more variations in the terrain;
determining an error computation based on a difference between at least one of (1) the predicted header height and the preselected header height, and (2) the predicted fluid pressure and the preselected fluid pressure;
generating a predicted input based, at least in part, on the error computation and a cost function evaluated over a period of time, the predicted input comprising at least one of a model header height and a model fluid pressure, wherein the cost function is subject to a plurality of constraints in a hierarchical arrangement, such that satisfaction of a higher-priority constraint of the plurality of constraints is prioritized regardless of whether such satisfaction causes a lower-priority constraint of the plurality of constraints to not be satisfied; and
adjusting, based on one or more control signals provided by the predicted input and before the header or the agricultural vehicle reaches the identified one or more variations in the terrain, the actual height of the header.
13 . The method of claim 12 , further comprising determining an outcome for the cost function, the outcome being at least a function of a difference between at least one of, when the sensor output is indicative of the actual height of the header and the predicted header height, and, when the sensor output is indicative of the fluid pressure of the fluid, the actual fluid pressure and the predicted fluid pressure.
14 . The method of claim 12 , wherein the plurality of constraints in the hierarchical arrangement comprises at least a first constraint and a second constraint, and wherein the first constraint is a higher-priority constraint that relates to at least one of a comfort of an operator of the agricultural vehicle or a stability of the agricultural vehicle or the header, and the second constraint is a lower-priority constraint that relates to at least one of a power consumption of one or more actuators used to adjust the actual height of the header or a speed or acceleration of a displacement of the header.
15 . The method of claim 12 , further comprising communicating at least a portion of the predicted input to the header model as a feedback signal.
16 . The method of claim 15 , further comprising adjusting the header model in response to the feedback signal.
17 . The method of claim 16 , wherein generating the predicted input further comprises generating the predicted input based, at least in part, on a constraint, and further comprising receiving a signal indicative of an operator defining the constraint.
18 . The method of claim 12 , further comprising evaluating an outcome for each of the plurality of constraints based on the hierarchical arrangement, wherein the higher-priority constraint relates to at least one of a comfort of an operator of the agricultural vehicle or a stability of the agricultural vehicle or the header, and wherein the lower-priority constraint relates to at least one of a power consumption of one or more actuators configured to adjust the actual height of the header or a speed or acceleration of a displacement of the header.
19 . The method of claim 12 , wherein generating the predicted output comprises applying one or more models of at least one of a mechanical system for when the predicted output is the predicted header height, and a hydraulic system of the header for when the predicted output is the predicted fluid pressure.
20 . The method of claim 19 , wherein generating the predicted output comprises applying one or more parameters to the header model, the one or more parameters being obtained from one or more datasheets or one or more lookup tables.