Ping Ren

YNICL Journal 2022 Journal Article

Imbalance between the caudate and putamen connectivity in obsessive–compulsive disorder

• Ziwen Peng
• Tingxin He
• Ping Ren
• Lili Jin
• Qiong Yang
• Chuanyong Xu
• Rongzhen Wen
• Jierong Chen

YNICL Journal 2018 Journal Article

Functional and structural connectivity of the amygdala underpins locus of control in mild cognitive impairment

• Ping Ren
• Benjamin Chapman
• Zhengwu Zhang
• Giovanni Schifitto
• Feng Lin

ICRA Conference 2012 Conference Paper

Dynamic trajectory planning of a two-DOF cable-suspended parallel robot

• Clément Gosselin
• Ping Ren
• Simon Foucault

This paper presents a trajectory planning approach for cable-suspended parallel mechanisms. A planar two-degree-of-freedom parallel mechanism is used for the analysis. Based on the dynamic model of the suspended robot, a set of algebraic inequalities is obtained that represents the constraints on the cable tensions. Parametric Cartesian trajectories are then defined and substituted into the constraints in order to obtain global conditions on the trajectory parameters which ensure that the trajectories are feasible. Special frequencies arise from the equations that are akin to natural frequencies of pendulum-type systems. An experimental validation is also presented using a two-dof prototype. The proposed trajectory planning approach can be used to plan dynamic trajectories that go beyond the static workspace of the mechanism, thereby opening novel applications and possibilities for cable-suspended robots.

IROS Conference 2009 Conference Paper

Experimental verification of the walking and turning gaits for a two-actuated spoke wheel robot

• Dennis W. Hong
• J. Blake Jeans
• Ping Ren

Intelligent Mobility Platform with Active Spoke System (IMPASS) is a novel wheel-leg hybrid robot that can walk in unstructured environments by stretching in or out three independently actuated spokes of each wheel. This form of novel locomotion has the potential to combine the efficiency of a wheeled robot and the mobility of a legged robot. A highly mobile robot such as IMPASS could prove very valuable in applications where the terrain is complex and dangerous, such as search and rescue, reconnaissance, or anti-terror response. This video presents the experiments and findings of a variety of straight-line walking, transitions, and turning gaits. With the 1- 1 and 2-2 straight walking gaits, the robot can move forward stably but with different constraints. Unlike other wheeled vehicles which use Arckerman steering or differential steering, IMPASS can implement novel turning gaits even though the left and right hubs rotate with the same angular velocity. Steady state turning gait is demonstrated with skew transitions. Additionally, a free form gait is demonstrated using joystick control with interesting observations.

ICRA Conference 2007 Conference Paper

STriDER: Self-Excited Tripedal Dynamic Experimental Robot

• Jeremy Heaston
• Dennis W. Hong
• Ivette Morazzani
• Ping Ren
• Gabriel Goldman

STriDER (Self-Excited Tripedal Dynamic Experimental Robot) is a novel three-legged walking machine that exploits the concept of actuated passive dynamic locomotion to dynamically walk with high energy efficiency and minimal control. Unlike other passive dynamic walking machines, this unique tripedal locomotion robot is inherently stable with its tripod stance, can change directions, and is relatively easy to implement, making it practical to be used for real life applications. STriDER begins its step with a stable stance like a camera tripod. As the center of gravity of the robot shifts forward pass the "pivot line" defined by the two feet of the stance legs, the robot begins to fall in the direction perpendicular to the pivot line. The middle leg naturally swings between the two stance legs using the concept of actuated passive dynamic locomotion. The swing leg then catches the fall and the robot resets to its original tripod posture in preparation for its next step. STriDER can easily change its direction of walking, simply by changing the sequence of choice of the swing leg and the stance legs. In this video, we present the concept of this novel walking machine and the mechanical design of the first prototype. The results from the dynamic simulation and a simple experiment for a single step are presented for comparison.