04 机械臂流式控制接口

流式控制接口用于运动目标在执行前未知，在执行过程中由上位机实时下发的场景。流式控制的核心是通过 start_streaming 获取一个流式控制句柄（Handle），然后通过句柄不断设置新的运动/控制目标。同时也提供了基于共享对象的方式，通过线程安全的共享变量来传递目标。

使用方式

流式控制有两种使用方式：

方式一：句柄模式

通过 start_streaming() 获取句柄，然后通过句柄下发运动目标。

RustPython

let mut handle = robot.start_streaming()?;
for target in trajectory {
    handle.move_to(MotionType::Joint(target))?;
    sleep(Duration::from_millis(1));
}
robot.end_streaming()?;

handle = robot.start_streaming()
for target in trajectory:
    handle.move_to(MotionType.Joint(target))
    sleep(0.001)
robot.end_streaming()

方式二：共享对象模式

通过 move_to_target() 等方法获取线程安全的共享对象，在其他线程中修改目标值。

ArmStreamingMotion 接口

RustPython

pub trait ArmStreamingMotion<const N: usize>: Arm<N> {
    type Handle: ArmStreamingHandle<N>;

    fn start_streaming(&mut self) -> RobotResult<Self::Handle>;
    fn end_streaming(&mut self) -> RobotResult<()>;
    fn move_to_target(&mut self) -> Arc<Mutex<Option<MotionType<N>>>>;
    fn control_with_target(&mut self) -> Arc<Mutex<Option<ControlType<N>>>>;
}

class ArmStreamingMotion:
    def start_streaming(self) -> ArmStreamingHandle: ...
    def end_streaming(self) -> None: ...
    def move_to_target(self) -> object: ...
    def control_with_target(self) -> object: ...

ArmStreamingMotionExt 扩展接口

扩展接口提供各种具体类型的共享对象访问：

RustPython

pub trait ArmStreamingMotionExt<const N: usize>: ArmStreamingMotion<N> {
    fn move_joint_target(&mut self) -> Arc<Mutex<Option<[f64; N]>>>;
    fn move_joint_vel_target(&mut self) -> Arc<Mutex<Option<[f64; N]>>>;
    fn move_joint_acc_target(&mut self) -> Arc<Mutex<Option<[f64; N]>>>;
    fn move_cartesian_target(&mut self) -> Arc<Mutex<Option<Pose>>>;
    fn move_cartesian_vel_target(&mut self) -> Arc<Mutex<Option<[f64; 6]>>>;
    fn move_cartesian_euler_target(&mut self) -> Arc<Mutex<Option<[f64; 6]>>>;
    fn move_cartesian_quat_target(&mut self) -> Arc<Mutex<Option<na::Isometry3<f64>>>>;
    fn move_cartesian_homo_target(&mut self) -> Arc<Mutex<Option<[f64; 16]>>>;
    fn control_tau_target(&mut self) -> Arc<Mutex<Option<[f64; N]>>>;
}

class ArmStreamingMotionExt:
    def move_joint_target(self) -> object: ...
    def move_joint_vel_target(self) -> object: ...
    def move_joint_acc_target(self) -> object: ...
    def move_cartesian_target(self) -> object: ...
    def move_cartesian_vel_target(self) -> object: ...
    def move_cartesian_euler_target(self) -> object: ...
    def move_cartesian_quat_target(self) -> object: ...
    def move_cartesian_homo_target(self) -> object: ...
    def control_tau_target(self) -> object: ...

流式控制句柄

ArmStreamingHandle 是流式控制的操作句柄，提供上一帧运动/控制目标的读取和新目标的设置：

RustPython

pub trait ArmStreamingHandle<const N: usize> {
    fn last_motion(&self) -> Option<MotionType<N>>;
    fn move_to(&mut self, target: MotionType<N>) -> RobotResult<()>;
    fn last_control(&self) -> Option<ControlType<N>>;
    fn control_with(&mut self, control: ControlType<N>) -> RobotResult<()>;
}

class ArmStreamingHandle:
    def last_motion(self) -> MotionType: ...
    def move_to(self, target: MotionType) -> None: ...
    def last_control(self) -> ControlType: ...
    def control_with(self, control: ControlType) -> None: ...