考虑一个南北长 3704米、东西宽 5808米的矩形海域内海域中心点处的海水深度为 110 m西深东浅坡度为 15∘多波束换能器的开角为 120∘。请设计一组测量长度最短、可完全覆盖整个待测海域的测线且相邻条带之间的重叠率满足 10~20 的要求。请用遗传算法找出符合要求最优的一组测线给出Python代码以及输出结果并绘制测线图
以下是一个使用遗传算法求解上述问题的Python代码:
import random
import math
import matplotlib.pyplot as plt
# 海域尺寸
length = 3704
width = 5808
# 海水深度
depth = 110
# 坡度
slope = 1.5
# 多波束换能器开角
beam_angle = 120
# 重叠率范围
overlap_min = 0.1
overlap_max = 0.2
# 测线类
class SurveyLine:
def __init__(self, start, end, depth, slope):
self.start = start
self.end = end
self.depth = depth
self.slope = slope
self.length = math.sqrt((end[0] - start[0])**2 + (end[1] - start[1])**2)
def get_overlap(self, other):
overlap = 0
if self.start[0] == other.start[0] and self.end[0] == other.end[0]:
overlap = min(self.end[1], other.end[1]) - max(self.start[1], other.start[1])
elif self.start[1] == other.start[1] and self.end[1] == other.end[1]:
overlap = min(self.end[0], other.end[0]) - max(self.start[0], other.start[0])
return overlap
def is_valid(self):
return self.depth + self.slope * self.length <= depth
def __repr__(self):
return f'Start: {self.start}, End: {self.end}, Depth: {self.depth}, Slope: {self.slope}, Length: {self.length}'
# 遗传算法类
class GeneticAlgorithm:
def __init__(self, population_size, generations, mutation_rate):
self.population_size = population_size
self.generations = generations
self.mutation_rate = mutation_rate
def initialize_population(self):
population = []
for _ in range(self.population_size):
start = (random.uniform(0, length), random.uniform(0, width))
end = (random.uniform(0, length), random.uniform(0, width))
depth = random.uniform(0, depth)
slope = random.uniform(0, slope)
line = SurveyLine(start, end, depth, slope)
population.append(line)
return population
def evaluate_fitness(self, population):
fitness_scores = []
for line in population:
fitness = line.length
for other_line in population:
if line != other_line:
overlap = line.get_overlap(other_line)
fitness += overlap
fitness_scores.append(fitness)
return fitness_scores
def select_parents(self, population, fitness_scores):
parents = []
total_fitness = sum(fitness_scores)
probabilities = [score / total_fitness for score in fitness_scores]
while len(parents) < 2:
random_num = random.random()
cumulative_prob = 0
for i, prob in enumerate(probabilities):
cumulative_prob += prob
if random_num <= cumulative_prob:
parents.append(population[i])
break
return parents
def crossover(self, parent1, parent2):
start = ((parent1.start[0] + parent2.start[0]) / 2, (parent1.start[1] + parent2.start[1]) / 2)
end = ((parent1.end[0] + parent2.end[0]) / 2, (parent1.end[1] + parent2.end[1]) / 2)
depth = (parent1.depth + parent2.depth) / 2
slope = (parent1.slope + parent2.slope) / 2
child = SurveyLine(start, end, depth, slope)
return child
def mutate(self, line):
mutated_line = line
if random.random() < self.mutation_rate:
mutated_line.start = (random.uniform(0, length), random.uniform(0, width))
if random.random() < self.mutation_rate:
mutated_line.end = (random.uniform(0, length), random.uniform(0, width))
if random.random() < self.mutation_rate:
mutated_line.depth = random.uniform(0, depth)
if random.random() < self.mutation_rate:
mutated_line.slope = random.uniform(0, slope)
return mutated_line
def evolve_population(self, population):
new_population = []
fitness_scores = self.evaluate_fitness(population)
for _ in range(self.population_size):
parent1, parent2 = self.select_parents(population, fitness_scores)
child = self.crossover(parent1, parent2)
mutated_child = self.mutate(child)
new_population.append(mutated_child)
return new_population
def find_best_line(self):
population = self.initialize_population()
for _ in range(self.generations):
population = self.evolve_population(population)
best_line = max(population, key=lambda line: line.length)
return best_line
# 创建遗传算法对象
ga = GeneticAlgorithm(population_size=100, generations=200, mutation_rate=0.1)
# 求解最优测线
best_line = ga.find_best_line()
print(best_line)
# 绘制测线图
fig, ax = plt.subplots()
ax.plot([best_line.start[0], best_line.end[0]], [best_line.start[1], best_line.end[1]], color='b')
ax.set_xlim([0, length])
ax.set_ylim([0, width])
plt.show()
输出结果可能会有所不同,但符合要求的测线应该具有较短的测线长度且能够覆盖整个海域。测线图将显示最优测线的起点和终点。
请注意,由于遗传算法的随机性质,每次运行代码的结果可能会有所不同。可以根据需要调整遗传算法的参数来获得更好的结果。
原文地址: https://www.cveoy.top/t/topic/i3hv 著作权归作者所有。请勿转载和采集!