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文章目录
- 前言
- 一、将无人机当成一个对象
- 1.1定义无人机相关属性
- 1.2定义用于控制无人机运动的代码
- 1.3主函数实现无人机的点位固定和飞行检测
- 二、用键盘控制测试代码
- 三、效果展示
- 四、注意点
前言
由于项目要求，现在需要做一个能够实现无人机根据事先给定的点位实现定点飞行，这里由于webots的跨平台性，考虑使用webots进行仿真
一、将无人机当成一个对象
1.1定义无人机相关属性
由于无人机有pitch、yaw、roll三个属性，分别对应前后运动、左右偏航和左右横滚、这里定义相关的所有属性用于控制。
同时定义相应的用于控制运动的函数
1.2定义用于控制无人机运动的代码
import math
import time
from controller import Robot, Camera, Compass, GPS, Gyro, InertialUnit, Keyboard, LED, Motor# 自定义无人机类，继承机器人父类
class UAV(Robot):timestep = 0# Constants, empirically found.k_vertical_thrust = 68.5 # with this thrust, the drone lifts.k_vertical_offset = 0.6 # Vertical offset where the robot actually targets to stabilize itself.k_vertical_p = 3.0 # P constant of the vertical PID.k_roll_p = 50.0 # P constant of the roll PID.k_pitch_p = 30.0 # P constant of the pitch PID.# 初始化变量def __init__(self):# Get and enable devices.self.camera = Camera("camera")self.camera.enable(timestep)self.front_left_led = LED("front left led")self.front_right_led = LED("front right led")self.imu = InertialUnit("inertial unit")self.imu.enable(timestep)self.gps = GPS("gps")self.gps.enable(timestep)self.compass = Compass("compass")self.compass.enable(timestep)# 检测角速度self.gyro = Gyro("gyro")self.gyro.enable(timestep)# keyboard = Keyboard()# keyboard.enable(timestep)# 横滚检测器self.camera_roll_motor = Motor("camera roll")# 前后俯仰检测器self.camera_pitch_motor = Motor("camera pitch")# 用于控制无人机平稳飞行的变量self.roll_disturbance = 0.0self.pitch_disturbance = 0.0self.yaw_disturbance = 0.0# 设置初始目标噶度self.target_altitude = 10.0# Get propeller motors and set them to velocity mode.self.front_left_motor = Motor("front left propeller")self.front_right_motor = Motor("front right propeller")self.rear_left_motor = Motor("rear left propeller")self.rear_right_motor = Motor("rear right propeller")# 将所有的驱动器保存到一个数组中self.motors = [self.front_left_motor, self.front_right_motor, self.rear_left_motor, self.rear_right_motor]# 前进def forward():self.pitch_disturbance = 2.0# 后退def backward():self.pitch_disturbance = -2.0# 向右运动def right():self.yaw_disturbance = 1.3# 向左运动def left():self.yaw_disturbance = -1.3# 向右横滚def roll_right():self.roll_disturbance = -1.0# 向左横滚def roll_left():self.roll_disturbance = 1.0# 上升def up():self.target_altitude += 0.05print("target altitude:", target_altitude, "[m]")# 下降def down():self.target_altitude -= 0.05print("target altitude:", target_altitude, "[m]")# 获取无人机当前位置def getPosition():self.roll = self.imu.getRollPitchYaw()[0] + math.pi / 2.0self.pitch = self.imu.getRollPitchYaw()[1]self.altitude = self.gps.getValues()[1]# 获取角速度self.roll_acceleration = self.gyro.getValues()[0]self.pitch_acceleration = self.gyro.getValues()[1]# Blink the front LEDs alternatively with a 1 second rate.self.led_state = int(time) % 2self.front_left_led.set(led_state)self.front_right_led.set(1 - led_state)# 根据相关参数进行运动控制def Move():# Stabilize the Camera by actuating the camera motors according to the gyro feedback.self.camera_roll_motor.setPosition(-0.115 * self.roll_acceleration)self.camera_pitch_motor.setPosition(-0.1 * self.pitch_acceleration)# Compute the roll, pitch, and yaw errors.roll_input = self.k_roll_p * CLAMP(self.roll, -1.0, 1.0) + self.roll_acceleration + self.roll_disturbancepitch_input = self.k_pitch_p * CLAMP(self.pitch, -1.0, 1.0) - self.pitch_acceleration + self.pitch_disturbanceyaw_input = self.yaw_disturbanceclamped_difference_altitude = CLAMP(self.target_altitude - self.altitude + self.k_vertical_offset, -1.0, 1.0)vertical_input = self.k_vertical_p * pow(clamped_difference_altitude, 3.0)# Accute the motor taking into consideration all the computed inputs.front_left_motor_input = self.k_vertical_thrust + vertical_input - roll_input - pitch_input + yaw_inputfront_right_motor_input = self.k_vertical_thrust + vertical_input + roll_input - pitch_input - yaw_inputrear_left_motor_input = self.k_vertical_thrust + vertical_input - roll_input + pitch_input - yaw_inputrear_right_motor_input = self.k_vertical_thrust + vertical_input + roll_input + pitch_input + yaw_inputself.front_left_motor.setVelocity(front_left_motor_input)self.front_right_motor.setVelocity(-front_right_motor_input)self.rear_left_motor.setVelocity(-rear_left_motor_input)self.rear_right_motor.setVelocity(rear_right_motor_input)# 辅助函数
def CLAMP(value, low, high):return max(low, min(value, high))1.3主函数实现无人机的点位固定和飞行检测
将主函数声明成控制器就可以了
from Uav import Uav
def main():uav = Uav()timestep = int(uav.getBasicTimeStep())uav.timestep = timestepkeyboard = Keyboard()keyboard.enable(timestep)while uav.step(timestep) != -1:key = keyboard.getKey()uav.roll_disturbance = 0.0uav.pitch_disturbance = 0.0uav.yaw_disturbance = 0.0while key > 0:# 上升函数if key == Keyboard.UP:uav.forward()elif key == Keyboard.DOWN:uav.backward()elif key == Keyboard.RIGHT:uav.right()elif key == Keyboard.LEFT:uav.left()elif key == (Keyboard.SHIFT + Keyboard.RIGHT):uav.roll_right()elif key == (Keyboard.SHIFT + Keyboard.LEFT):uav.roll_left()elif key == (Keyboard.SHIFT + Keyboard.UP):uav.up()elif key == (Keyboard.SHIFT + Keyboard.DOWN):uav.down()key = keyboard.getKey()uav.getPosition()uav.Move()wb_robot_cleanup();if __name__ == "__main__" :main()二、用键盘控制测试代码
由于webots默认给的是通过C++代码实现键盘对无人机进行控制，然而开发使用的多是python，这里给出根据原本C++代码改写的python控制代码，直接新建成一个控制器然后在webots中选择这个.py文件作为控制器就可以了，记得放到controler文件夹中。
import math
import time
from controller import Robot, Camera, Compass, GPS, Gyro, InertialUnit, Keyboard, LED, Motordef CLAMP(value, low, high):return max(low, min(value, high))def main():# 创建一个机器人对象robot = Robot()# 每个物理动作的持续时间timestep = int(robot.getBasicTimeStep())# Get and enable devices.camera = Camera("camera")camera.enable(timestep)front_left_led = LED("front left led")front_right_led = LED("front right led")imu = InertialUnit("inertial unit")imu.enable(timestep)gps = GPS("gps")gps.enable(timestep)compass = Compass("compass")compass.enable(timestep)# 检测角速度gyro = Gyro("gyro")gyro.enable(timestep)keyboard = Keyboard()keyboard.enable(timestep)# 横滚检测器camera_roll_motor = Motor("camera roll")# 前后俯仰检测器camera_pitch_motor = Motor("camera pitch")# Get propeller motors and set them to velocity mode.front_left_motor = Motor("front left propeller")front_right_motor = Motor("front right propeller")rear_left_motor = Motor("rear left propeller")rear_right_motor = Motor("rear right propeller")motors = [front_left_motor, front_right_motor, rear_left_motor, rear_right_motor]for motor in motors:# 初始化无限旋转的运动motor.setPosition(float('inf'))# 启动！motor.setVelocity(1.0)# Display the welcome message.print("Start the drone...")# Wait one second.while robot.step(timestep) != -1:if robot.getTime() > 1.0:break# Display manual control message.print("You can control the drone with your computer keyboard:")print("- 'up': move forward.")print("- 'down': move backward.")print("- 'right': turn right.")print("- 'left': turn left.")print("- 'shift + up': increase the target altitude.")print("- 'shift + down': decrease the target altitude.")print("- 'shift + right': strafe right.")print("- 'shift + left': strafe left.")# Constants, empirically found.k_vertical_thrust = 68.5 # with this thrust, the drone lifts.k_vertical_offset = 0.6 # Vertical offset where the robot actually targets to stabilize itself.k_vertical_p = 3.0 # P constant of the vertical PID.k_roll_p = 50.0 # P constant of the roll PID.k_pitch_p = 30.0 # P constant of the pitch PID.# Variables.# 设置初始高度target_altitude = 1.0 # The target altitude. Can be changed by the user.# Main loop# - perform simulation steps until Webots is stopping the controllerwhile robot.step(timestep) != -1:time = robot.getTime()# Retrieve robot position using the sensors.roll = imu.getRollPitchYaw()[0] + math.pi / 2.0pitch = imu.getRollPitchYaw()[1]altitude = gps.getValues()[1]# 获取角速度roll_acceleration = gyro.getValues()[0]pitch_acceleration = gyro.getValues()[1]# Blink the front LEDs alternatively with a 1 second rate.led_state = int(time) % 2front_left_led.set(led_state)front_right_led.set(1 - led_state)# Stabilize the Camera by actuating the camera motors according to the gyro feedback.camera_roll_motor.setPosition(-0.115 * roll_acceleration)camera_pitch_motor.setPosition(-0.1 * pitch_acceleration)# Transform the keyboard input to disturbances on the stabilization algorithm.roll_disturbance = 0.0pitch_disturbance = 0.0yaw_disturbance = 0.0key = keyboard.getKey()while key > 0:# 上升函数if key == Keyboard.UP:pitch_disturbance = 2.0elif key == Keyboard.DOWN:pitch_disturbance = -2.0elif key == Keyboard.RIGHT:yaw_disturbance = 1.3elif key == Keyboard.LEFT:yaw_disturbance = -1.3elif key == (Keyboard.SHIFT + Keyboard.RIGHT):roll_disturbance = -1.0elif key == (Keyboard.SHIFT + Keyboard.LEFT):roll_disturbance = 1.0elif key == (Keyboard.SHIFT + Keyboard.UP):target_altitude += 0.05print("target altitude:", target_altitude, "[m]")elif key == (Keyboard.SHIFT + Keyboard.DOWN):target_altitude -= 0.05print("target altitude:", target_altitude, "[m]")key = keyboard.getKey()# Compute the roll, pitch, and yaw errors.roll_input = k_roll_p * CLAMP(roll, -1.0, 1.0) + roll_acceleration + roll_disturbancepitch_input = k_pitch_p * CLAMP(pitch, -1.0, 1.0) - pitch_acceleration + pitch_disturbanceyaw_input = yaw_disturbanceclamped_difference_altitude = CLAMP(target_altitude - altitude + k_vertical_offset, -1.0, 1.0)vertical_input = k_vertical_p * pow(clamped_difference_altitude, 3.0)# Accute the motor taking into consideration all the computed inputs.front_left_motor_input = k_vertical_thrust + vertical_input - roll_input - pitch_input + yaw_inputfront_right_motor_input = k_vertical_thrust + vertical_input + roll_input - pitch_input - yaw_inputrear_left_motor_input = k_vertical_thrust + vertical_input - roll_input + pitch_input - yaw_inputrear_right_motor_input = k_vertical_thrust + vertical_input + roll_input + pitch_input + yaw_inputfront_left_motor.setVelocity(front_left_motor_input)front_right_motor.setVelocity(-front_right_motor_input)rear_left_motor.setVelocity(-rear_left_motor_input)rear_right_motor.setVelocity(rear_right_motor_input)wb_robot_cleanup()if __name__ == "__main__":main()
三、效果展示
用python控制器实现键盘控制无人机运动
四、注意点
- Webots中不支持到其他库，所以理论上应该都写在一个文件夹中，如果想要写在不用的文件夹中，需要
- 改变控制器以后记得重新保存一份世界文件。
解决方案.doc)
