基于Sigmoid函数的非对称式S型曲线机械臂加减速控制方法

Asymmetric S-curve manipulator acceleration and deceleration control method based on Sigmoid function

机械臂广泛应用于制造、装配、搬运、码垛等方面,对提高生产力起着重要作用。为减小机械臂在运动过程中的振动和冲击,提高机械臂轨迹执行效率,提出一种非对称式S型曲线加减速控制方法。该方法通过在双段Sigmoid函数中插入直线段,构成加加速度连续的运动学曲线。通过粒子群算法进行参数优化求解,无需反复确认每个时间段的存在性即可求出非对称约束下的曲线参数,并分别在关节空间和笛卡尔空间采用时间同步和位移同步方法使机械臂的运动轨迹更加协调自然。结果表明,相同条件下提出的方法比三角函数方法轨迹执行效率更高且加加速度仅为三角函数方法的55%。与梯形加加速度曲线相比,采用提出的方法规划的运动轨迹可减少35.7%的残余振动,验证了该方法的有效性。

Manipulator are widely used in manufacturing,assembly,handling,palletizing,etc.,and play an important role in improving productivity.In order to reduce the vibration and impact of the manipulator during movement and improve the efficiency of the robot trajectory execution,an asymmetric S-shaped curve acceleration and deceleration control method is proposed.A straight line is inserted into the double-segment Sigmoid function to form a kinematic curve with continuous acceleration.Solving parameters through particle swarm optimization algorithm,the curve parameters can be obtained without repeatedly confirming the existence of each time period.Using time synchronization and displacement synchronization methods in joint space and Cartesian space makes the motion trajectory of the robotic arm more coordinated and natural.The results show that under the same conditions,the proposed method has higher trajectory execution efficiency than the trigonometric function method and the acceleration is only 55%of the trigonometric function method.Compared with the trapezoidal speed curve,the motion trajectory planned by the proposed method can reduce residual vibration by 35.7%,verified the effectiveness of the proposed method.