stm32蓝牙小车pid算法

### STM32蓝牙小车PID算法实现 #### 连接硬件组件 为了构建基于STM32的蓝牙小车并应用PID算法，需先连接必要的硬件组件。五路循迹传感器应按照如下方式连接至STM32微控制器：VCC端接到5V电源，GND接地；OUT1-OUT5分别对应PA4, PA5, PA6, PA7以及PB0引脚用于读取地面反射光强度变化情况来判断轨迹偏差[^1]。 #### 初始化外设配置 在软件层面初始化过程中，要设置好定时器产生PWM信号给L293D电机驱动模块控制左右两侧直流电机的速度方向，同时开启ADC转换功能获取来自光电感应阵列的数据输入值作为反馈量参与后续计算处理过程之中[^2]。 ```c // 配置TIM3 PWM输出通道1 (PA6) 和通道2 (PA7) void TIM_Config(void){ GPIO_InitTypeDef GPIO_InitStruct; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_OCInitTypeDef TIM_OCInitStruct; RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE); GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7; GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP; GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOA,&GPIO_InitStruct); TIM_TimeBaseStructInit(&TIM_TimeBaseStructure); TIM_TimeBaseStructure.TIM_Period = 999; TIM_TimeBaseStructure.TIM_Prescaler = 71; TIM_TimeBaseStructure.TIM_ClockDivision = 0; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); TIM_OCStructInit(&TIM_OCInitStruct); TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High; TIM_OCInitStruct.TIM_Pulse = 0; TIM_OC1Init(TIM3, &TIM_OCInitStruct); TIM_OC2Init(TIM3, &TIM_OCInitStruct); TIM_Cmd(TIM3, ENABLE); } ``` #### 设计PID调节逻辑 针对具体应用场景设计合理的比例系数Kp、积分时间常数Ki和微分时间Td参数组合形式以达到最优性能指标要求。当检测到偏离中心线位置时，则依据误差大小调整前后轮差速从而纠正行驶路径直至恢复正常状态为止[^3]。 ```c float Kp = 8.0f, Ki = 0.0f, Kd = 0.0f; float prev_error = 0.0f; float integral = 0.0f; int Calculate_PID(int target_position, int current_position){ float error = target_position - current_position; integral += error * SAMPLE_TIME; float derivative = (error - prev_error)/SAMPLE_TIME; float output = Kp*error + Ki*integral + Kd*derivative; prev_error = error; return constrain(output,-MAX_SPEED, MAX_SPEED); } #define TARGET_POSITION 2 // 假设目标位于中间第三个传感器处 while(1){ uint16_t adc_values[5]; ADC_GetMultiValues(adc_values); motor_speed_diff = Calculate_PID(TARGET_POSITION, find_max_index(adc_values)); set_motor_speed(motor_speed_diff); } ```