Author Contributions
Conceptualization, Z.Q. and H.G.; methodology, Z.Q.; software, Z.Q.; validation, Z.Q., G.G. and T.W.; formal analysis, H.C.; investigation, X.W.; resources, H.G.; data curation, Z.Q.; writing—original draft preparation, Z.Q.; writing—review and editing, Z.Q. and H.G.; supervision, G.G.; project administration, H.G.; funding acquisition, H.G. All authors have read and agreed to the published version of the manuscript.
Figure 1.
Main structure of the safflower-picking robot. 1: Navigation system; 2: Leveling system; 3: Power system; 4: Identification and positioning system; 5: Picking system.
Figure 1.
Main structure of the safflower-picking robot. 1: Navigation system; 2: Leveling system; 3: Power system; 4: Identification and positioning system; 5: Picking system.
Figure 2.
Workflow diagram of the whole machine.
Figure 2.
Workflow diagram of the whole machine.
Figure 3.
Characterization of acceleration and deceleration curves. A max signifies the maximum acceleration of the end−effector of the Delta robotic arm, whereas Vmax indicates the maximum speed of the end−effector of the Delta robotic arm. t1 is the time during which acceleration increases during the acceleration phase, t2 is the time during which acceleration decreases during the acceleration phase, t3 to t5 represent the period when the speed is constant at its maximum during the uniform motion phase, t6 is the time during which acceleration increases during the deceleration phase, and t7 is the time during which acceleration decreases during the deceleration phase.
Figure 3.
Characterization of acceleration and deceleration curves. A max signifies the maximum acceleration of the end−effector of the Delta robotic arm, whereas Vmax indicates the maximum speed of the end−effector of the Delta robotic arm. t1 is the time during which acceleration increases during the acceleration phase, t2 is the time during which acceleration decreases during the acceleration phase, t3 to t5 represent the period when the speed is constant at its maximum during the uniform motion phase, t6 is the time during which acceleration increases during the deceleration phase, and t7 is the time during which acceleration decreases during the deceleration phase.
Figure 4.
Motion path: (a) traditional gate-type path; (b) improved gate-type path.
Figure 4.
Motion path: (a) traditional gate-type path; (b) improved gate-type path.
Figure 5.
Cycle diagram of a single trajectory for safflower picking.
Figure 5.
Cycle diagram of a single trajectory for safflower picking.
Figure 6.
Bezier curve. where xyz is the static platform coordinate system, A, C, E are second-order Bessel curve reference points, A, B, D, E are third-order Bessel curve reference points, and A, B, C, D, E are fourth-order Bessel curve reference points.
Figure 6.
Bezier curve. where xyz is the static platform coordinate system, A, C, E are second-order Bessel curve reference points, A, B, D, E are third-order Bessel curve reference points, and A, B, C, D, E are fourth-order Bessel curve reference points.
Figure 7.
Schematic diagram of safflower filament harvesting movement: (a) the spatial distribution of harvesting points; (b) the movement pathway for harvesting. Where xyz is the coordinate system of the starting point for trajectory planning.
Figure 7.
Schematic diagram of safflower filament harvesting movement: (a) the spatial distribution of harvesting points; (b) the movement pathway for harvesting. Where xyz is the coordinate system of the starting point for trajectory planning.
Figure 8.
Optimization analysis of the ant colony algorithm.
Figure 8.
Optimization analysis of the ant colony algorithm.
Figure 9.
Adaptive schematic: (a) ants release pheromones; (b) smaller values of; (c) larger values of. Where A, B, C and D are path points that require trajectory planning.
Figure 9.
Adaptive schematic: (a) ants release pheromones; (b) smaller values of; (c) larger values of. Where A, B, C and D are path points that require trajectory planning.
Figure 10.
Schematic diagram of restriction pheromone: (a) ants release pheromone; (b) no limiting pheromone; (c) limiting pheromone. Where A, B, C and D are path points that require trajectory planning.
Figure 10.
Schematic diagram of restriction pheromone: (a) ants release pheromone; (b) no limiting pheromone; (c) limiting pheromone. Where A, B, C and D are path points that require trajectory planning.
Figure 11.
Flowchart of the ant colony genetic algorithm.
Figure 11.
Flowchart of the ant colony genetic algorithm.
Figure 12.
Field safflower locations.
Figure 12.
Field safflower locations.
Figure 13.
Algorithm optimization results. (a) Iteration curve of the improved ant colony algorithm based on 15 safflower flowers; (b) Iteration curve of the ant colony genetic algorithm based on 15 safflower flowers; (c) Lengths of 20 optimized paths based on 15 safflower flowers; (d) Iteration curve of the improved ant colony algorithm based on 30 safflower flowers; (e) Iteration curve of the ant colony genetic algorithm based on 30 safflower flowers; (f) Lengths of 20 optimized paths based on 30 safflower flowers.
Figure 13.
Algorithm optimization results. (a) Iteration curve of the improved ant colony algorithm based on 15 safflower flowers; (b) Iteration curve of the ant colony genetic algorithm based on 15 safflower flowers; (c) Lengths of 20 optimized paths based on 15 safflower flowers; (d) Iteration curve of the improved ant colony algorithm based on 30 safflower flowers; (e) Iteration curve of the ant colony genetic algorithm based on 30 safflower flowers; (f) Lengths of 20 optimized paths based on 30 safflower flowers.
Figure 14.
Ant colony genetic algorithm picking trajectory map.
Figure 14.
Ant colony genetic algorithm picking trajectory map.
Figure 15.
Safflower-picking robot field experiment.
Figure 15.
Safflower-picking robot field experiment.
Table 1.
Design value of the task.
Table 1.
Design value of the task.
Mandates | Working Condition 1 | Working Condition 2 |
---|
Coordinate Value | Motor Running Angle |
---|
Starting coordinate value | (0, 0, 0) | (, , ) |
Endpoint coordinate value | (100, 50, 50) | (, , ) |
Speed limit | 10 (mm/s) | 1.8 (rad/s) |
Acceleration constraint | 30 (mm/s2) | 10 (rad/s2) |
Jerk constraints | 30 (mm/s3) | 50 (rad/s3) |
Table 2.
Optimum working time for reference conditions.
Table 2.
Optimum working time for reference conditions.
| Speed Curve | Time/s |
---|
Working condition 1 | S-curve model | 5.728 |
Improved S-curve model | 5.032 |
Working condition 2 | S-curve model | 3.988 |
Improved S-curve model | 3.088 |
Table 3.
Maximum urgency and average urgency.
Table 3.
Maximum urgency and average urgency.
Algorithm | Maximum Jerk | Average Jerk |
---|
Joints 1 | Joints 2 | Joints 3 | Joints 1 | Joints 2 | Joints 3 |
---|
(mm/s3) |
---|
Working condition 1 | S-curve model | 27.3 | 21.4 | 20.2 | 17.54 | 16.88 | 18.92 |
Improved S-curve model | 7.3 | 7.8 | 6.8 | 6.81 | 7.22 | 6.42 |
Working condition 2 | S-curve model | 48.2 | 49.5 | 45.8 | 28.24 | 24.58 | 27.35 |
Improved S-curve model | 25.3 | 25.0 | 24.8 | 15.42 | 14.08 | 14.22 |
Table 4.
Comparison of velocity profile model simulation results.
Table 4.
Comparison of velocity profile model simulation results.
Safflower Count | Models | Time/s | |
---|
15 | Improved S-curve model | 44.2642 | 10.4342 |
S-curve model | 51.5422 | 23.4251 |
30 | Improved S-curve model | 76.4586 | 13.6485 |
S-curve model | 98.3549 | 28.4265 |
Table 5.
Genetic algorithm optimization results safflower flowers.
Table 5.
Genetic algorithm optimization results safflower flowers.
Count | Considerations |
---|
| | | |
---|
15 | 2.46 | 8.99 | 1734.80 | 25.69 |
30 | 2.30 | 8.85 | 387.59 | 59.54 |
Table 6.
Genetic algorithm optimization results safflower harvesting.
Table 6.
Genetic algorithm optimization results safflower harvesting.
Amount of Safflower | Average Working Time/s |
---|
Imitate Manual Picking | Basic Ant Colony Algorithm | Ant Colony Genetic Algorithm |
---|
small amount (15) | 64.354 | 46.172 | 43.244 |
large amount (30) | 111.465 | 77.524 | 72.246 |