针对现有LNG装卸场站槽车充装多为手动充装、人工推动接车臂操作困难、劳动强度大、耗时长、效率低等问题,提出一种具备在划定车辆停靠区域情况下自动对接的LNG硬管接车臂的控制方法。一是实时采集各执行机构的位移,换算为各旋转关节运动的角度及角速度,为有效抑制干扰,防止信号突变,引入一阶滞后滤波算法,滤波后反馈给控制系统；二是通过DH表示法建立接车臂的运动学模型,进行接车臂的正、逆运动学分析;三是在笛卡尔直角坐标空间规划接车臂末端的实时空间位姿及其对应的速度、加速度;四是建立外环角度控制,内环角速度控制的位置速度双环控制器;五是采用Matalb机器人工具验证正运动学解算表达式的正确性及接车臂运动范围仿真,通过阶跃信号仿真双环与单环PID控制算法的控制效果,实际测试表明自动对接准确率可达99%,相比手动对接时间可节约30%,可有效提高对接效率,减少操作人员数量及劳动强度。LNG硬管接车臂的自动对接控制方法能较好地应用于LNG装卸场站槽车充装自动对接,具有一定的推广和参考价值。

The existing LNG loading and unloading station tank car filling has many issues such as manual filling, difficult operation of manually pushing the connecting arm, high labor intensity, long duration, low efficiency, etc. To address these issues, this paper proposes a control method of LNG rigid pipe receiving arm with automatic docking that operates within the boundary of a pre-defined vehicle parking area. The first is to collect the displacement of each actuator in real time, and convert it into the angle and angular velocity of each rotary joint motion. In order to effectively suppress interference, prevent signal from mutation, the 1st-order lag filtering algorithm is introduced, and the filtered signalis fed back to the control system. The second is to establish the kinematics model of the receiving arm through D-H (Denavit-Hartenberg) representation. The forward and inverse kinematics analysis of the connecting arm is then carried out. The third is to plan the position and posture of the receiving arm end in real time and space and its corresponding velocity and acceleration in Cartesian rectangular coordinate space. The fourth is to establish the position and velocity dual-loop controller of the outer loop angle control and the inner loop angular velocity control. The fifth, the Matalb robot tool is used to verify the correctness of the forward kinematics solution expression and the simulation of the motion range of the connecting arm. The control effect of the double-loop and single-loop PID (Proportional-Integral-Derivative) control algorithms is simulated using a step signal. The actual test shows that the accuracy of automatic docking can reach 99%, which can save 30% docking time as compared with the manual operation, effectively improve the docking efficiency, reduce the number of operators and labor intensity. The new method can be better and widely used in tank car filling automatic docking in LNG loading and unloading stations, and definitely has value as reference and in promoting such application.