A Smooth Motion Path Planning Method for Six-axis Robots Considering Redundancy

doi:10.3969/j.issn.1004-132X.2025.11.021

China Mechanical Engineering ›› 2025, Vol. 36 ›› Issue (11): 2652-2657.DOI: 10.3969/j.issn.1004-132X.2025.11.021

A Smooth Motion Path Planning Method for Six-axis Robots Considering Redundancy

Haiping LIANG¹^,²^,³^,⁴(), Yaoan LU¹^,²^,³^,⁴(), Weijia LIAN¹^,²^,³^,⁴, Chengyong WANG¹^,²^,³^,⁴

^1.School of Electromechanical Engineering，Guangdong University of Technology，Guangzhou，510006
^2.Guangdong Provincial Key Laboratory of Minimally Invasive Surgical Instruments and Manufacturing Technology，Guangdong University of Technology，Guangzhou，510006
^3.State Key Laboratory of High Performance Tools，Guangzhou，510006
^4.Smart Medical Innovation Technology Center，Guangdong University of Technology，Guangzhou，510006

Received:2025-02-27 Online:2025-11-25 Published:2025-12-09
Contact: Yaoan LU

考虑冗余自由度的六轴机器人光顺运动路径规划方法

梁海平¹^,²^,³^,⁴(), 卢耀安¹^,²^,³^,⁴(), 连伟嘉¹^,²^,³^,⁴, 王成勇¹^,²^,³^,⁴

^1.广东工业大学机电工程学院, 广州, 510006
^2.广东工业大学广东省微创手术器械设计与精密制造重点实验室, 广州, 510006
^3.高性能工具全国重点实验室, 广州, 510006
^4.广东工业大学智慧医疗创新技术中心, 广州, 510006

通讯作者: 卢耀安
作者简介:梁海平，男，2000年生，硕士研究生。研究方向为骨科手术机器人。E-mail： 936581850@qq.com。
基金资助:
广东省基础与应用基础研究基金(2025A1515012218)

Abstract

Abstract:

The existing redundancy optimization methods might fail to fully exploit the robot's redundancy when six-axis industrial robots performing five-axis machining tasks， limiting the smoothness of the planned motion path. An efficient algorithm was proposed for collision-free and smooth joint motion planning of six-axis robots. The method fully utilized the robot's redundancy by varying the redundancy variable at each cutter location data to generate all possible candidate robot postures. To enhance computational efficiency， a two-step search strategy was introduced combining rough and fine searches with a greedy approach， and the robot postures were selected from feasible postures with greedy strategy. The proposed method does not require segmenting the machining path and may optimize the robot's posture along the entire machining path simultaneously. The effectiveness of the proposed algorithm was validated by simulation calculations on joint motion paths of six-axis industrial robots conducting five-axis milling surface machining tasks.

Key words: robotic machining, redundancy optimization, smooth joint motion, collision avoidance

摘要：

现有的冗余优化方法在六轴机器人执行五轴加工任务时往往未能充分利用机器人的冗余自由度，影响所规划运动路径的光顺效果。提出了一种高效的六轴机器人无碰撞且光顺的关节运动路径规划方法，该方法通过改变每个刀位数据处的冗余变量来生成所有可行的机器人姿态，充分利用机器人的冗余自由度。为了提高计算效率，引入了结合粗搜索和精搜索的两步搜索策略，并采用贪心策略从可行姿态里选择机器人姿态。该方法无需分割加工路径，可以同时优化整个加工路径的机器人姿态。仿真计算了六轴机器人执行五轴铣削加工曲面任务的关节运动路径，验证了所提方法的有效性。

关键词: 机器人加工, 冗余优化, 光顺关节运动, 碰撞避免

CLC Number:

TP242

Haiping LIANG, Yaoan LU, Weijia LIAN, Chengyong WANG. A Smooth Motion Path Planning Method for Six-axis Robots Considering Redundancy[J]. China Mechanical Engineering, 2025, 36(11): 2652-2657.

梁海平, 卢耀安, 连伟嘉, 王成勇. 考虑冗余自由度的六轴机器人光顺运动路径规划方法[J]. 中国机械工程, 2025, 36(11): 2652-2657.

Figures/Tables 8

Fig. 1 Flowchart of collision detection

Fig. 2 Two-stage technique for joint motion planning

Fig. 3 Schematic of joint angle selection with greedy strategy

Fig. 4 Search strategy combining rough and fine searches

Fig. 5 The tool path and the setup for milling （UR5）

Fig. 6 Comparisons of the results of different methods （UR5）

Fig. 7 The five-axis tool path and the setup for milling （Motoman MH180）

Fig. 8 Comparisons of the results of different methods （Motoman MH180）

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A Smooth Motion Path Planning Method for Six-axis Robots Considering Redundancy

考虑冗余自由度的六轴机器人光顺运动路径规划方法

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