US 12,324,371 B1
Navigation method and system for caterpillar-type agricultural machinery during loss of navigation real-time kinematic signal
Jian Zhang, Hainan (CN); Yang Liu, Hainan (CN); Ranbing Yang, Hainan (CN); Huihui Wen, Hainan (CN); Yongfei Pan, Hainan (CN); Shiting Lv, Hainan (CN); Ang Zhao, Hainan (CN); Xinyu Guo, Hainan (CN); Hongfei Zhu, Hainan (CN); Zhuhe Shao, Hainan (CN); and Yao Li, Hainan (CN)
Assigned to Hainan University, Haikou (CN)
Filed by Hainan University, Hainan (CN)
Filed on Dec. 27, 2024, as Appl. No. 19/004,185.
Claims priority of application No. 202410043956.3 (CN), filed on Jan. 11, 2024.
Int. Cl. A01D 41/127 (2006.01)
CPC A01D 41/127 (2013.01) 7 Claims
OG exemplary drawing
 
1. A navigation method for caterpillar-type agricultural machinery during loss of a navigation real-time kinematic (RTK) signal, comprising the steps of:
S1, acquiring operation parameter information about the caterpillar-type agricultural machinery before signal loss, and adjusting a state of the caterpillar-type agricultural machinery based on the operation parameter information, and
S2, calculating an operation deviation amount after adjusting the state of the caterpillar-type agricultural machinery for a time t, and adjusting heading information about the caterpillar-type agricultural machinery based on the deviation amount until the caterpillar-type agricultural machinery returns to an original planned route to complete navigation,
S2 comprising:
S21, calculating the operation deviation amount, and travelling parameters for travelling back to the original planned route when the operation deviation amount is greater than a pre-set value, and returning to the original planned route based on the travelling parameters,
S21 comprising:
S211, calculating, when the operation deviation amount is greater than the pre-set value, an arc radius required for the caterpillar-type agricultural machinery to travel back to the original planned route,
S212, calculating linear velocities of left and right wheels of the caterpillar-type agricultural machinery to travel back to the original planned route, and calculating a differential velocity of the left and right wheels based on the linear velocities,
when a vehicle body is deviated to the right:

OG Complex Work Unit Math
where VL and VR are velocities of the left and right wheels, respectively; R represents an arc radius; L represents a wheelbase of the left and right wheels; and w represents an angular velocity of travelling;
when the vehicle body is deviated to the left:

OG Complex Work Unit Math
the differential velocity of the left and right wheels being:
ΔV=VR−VL; and
S213, calculating the time required for the caterpillar-type agricultural machinery to travel back to the original planned route, and calculating and adjusting the differential velocity of the left and right wheels in real time to realize the returning of the vehicle body to the original planned route,

OG Complex Work Unit Math
where θ is an angle between the heading of a vehicle body and an original planned route straight line; S2 is an arc length traveled by the caterpillar-type agricultural machinery after adjustment once; Z is a parameter for adjusting the differential velocity of the left and right wheels, turning left when Z>0 and turning right when Z<0; n represents the number of real-time calculations; h represents a real-time deviation distance; e represents a natural constant; A, B, C and D are constant coefficients, and are adjusted according to a mass of the caterpillar-type agricultural machinery, the ground friction force and the actual power transmission difference between caterpillar bands; d represents a deviation amount; S1 is a straight-line distance traveled;
and s is a total distance; and
S22, travelling along a current heading when the deviation amount is less than the pre-set value, and repeating S21.