Controlling spot spraying of agrochemicals

A spot spray control system for spraying agrochemicals using a spray assembly, the spray assembly comprising an array of nozzles and the spot spray control system comprising:

• a processor (1802);
• one or more interfaces (1810, 1812) configured to receive target object data and output control signals to the spray assembly;
• and
• memory (1808) arranged to store a computer program which, when executed by the processor, causes the control system to:
• (i) define a position of a first spot spray based on a position of a leading edge of a target object (702);
• (ii) define an initial position in terms of a transverse offset and a longitudinal offset relative to the first spot spray, of at least one new adjacent spot spray (704, 1204) such that the combined dose of the first and new spot sprays forms a continuous spray zone that covers a portion of the target object, wherein each of the first and new spot sprays is defined by a non-homogenous two-dimensional liquid spatial distribution and the transverse offset is a multiple of an effective spacing of the nozzles in the array of nozzles;
• (iii) determine a two-dimensional dose map resulting from the first and new spot sprays (706);
• (iv) in response to determining, from the two-dimensional dose map, that pre-defined dose criteria are not met (707), adjust the offsets of the at least one new adjacent spot spray to optimise a received dose (708, 1208);
• (v) generate control signals for the array of nozzles according to the position of the first spot spray and adjusted offsets of the at least one new adjacent spot spray (710);
• and
• (vi) output the control signals to the spray assembly via the one or more interfaces.

A method of operation of a spot spray control system for spraying agrochemicals using a spray assembly, the spray assembly comprising an array of nozzles and the method comprising:

• determining, using pre-calculated tables, a longitudinal offset of a first spot spray, transverse and longitudinal offsets for one or more new adjacent spot sprays (1704), and a nozzle opening duration of each spot spray, wherein each of the first and new spot sprays is defined by a non-homogenous two-dimensional liquid spatial distribution and the transverse offset is a multiple of an effective spacing of the nozzles in the array of nozzles;
• defining a position of the first spot spray based on a position of a leading edge of a target object and the determined longitudinal offset of the first spot spray;
• defining positions of the one or more new adjacent spot sprays relative to the position of the first spot spray based on the determined transverse and longitudinal offsets for the one or more new adjacent spot sprays (1706);
• generating control signals for the array of nozzles according to the position of the first spot spray and the one or more new adjacent spot sprays, the opening duration for each spot spray and a displacement speed of the nozzles (710);
• and
• outputting the control signals to the spray assembly.

A spot spray control system for spraying agrochemicals using a spray assembly, the spray assembly comprising an array of nozzles and the spot spray control system comprising:

• a processor (1802);
• one or more interfaces (1810, 1812) configured to receive target object data and output control signals to the spray assembly;
• and
• memory (1808) arranged to store a computer program which, when executed by the processor, causes the control system to:
• determine, using pre-calculated tables, a longitudinal offset of a first spot spray, transverse and longitudinal offsets for one or more new adjacent spot sprays (1704), and a nozzle opening duration for each spot spray, wherein each of the first and new spot sprays is defined by a non-homogenous two-dimensional liquid spatial distribution and the transverse offset is a multiple of an effective spacing of the nozzles in the array of nozzles;
• define a position of the first spot spray based on a position of a leading edge of a target object and the determined longitudinal offset of the first spot spray;
• define positions of the one or more new adjacent spot sprays relative to the position of the first spot spray based on the determined transverse and longitudinal offsets for the one or more new adjacent spot sprays (1706);
• generate control signals for the array of nozzles according to the position of the first spot spray and the one or more new adjacent spot sprays, the opening duration for each spot spray and a displacement speed of the nozzles (710);
• and
• output the control signals to the spray assembly via the one or more interfaces.