Nailong Liu, Xiaodong Zhou, Zhaoming Liu, Hongwei Wang and Long Cui
This paper aims to enable the robot to obtain human-like compliant manipulation skills for the peg-in-hole (PiH) assembly task by learning from demonstration.
Abstract
Purpose
This paper aims to enable the robot to obtain human-like compliant manipulation skills for the peg-in-hole (PiH) assembly task by learning from demonstration.
Design/methodology/approach
A modified dynamic movement primitives (DMPs) model with a novel hybrid force/position feedback in Cartesian space for the robotic PiH problem is proposed by learning from demonstration. To ensure a compliant interaction during the PiH insertion process, a Cartesian impedance control approach is used to track the trajectory generated by the modified DMPs.
Findings
The modified DMPs allow the robot to imitate the trajectory of demonstration efficiently and to generate a smoother trajectory. By taking advantage of force feedback, the robot shows compliant behavior and could adjust its pose actively to avoid a jam. This feedback mechanism significantly improves the dynamic performance of the interactive process. Both the simulation and the PiH experimental results show the feasibility and effectiveness of the proposed model.
Originality/value
The trajectory and the compliant manipulation skill of the human operator can be learned simultaneously by the new model. This method adopted a modified DMPs model in Cartesian space to generate a trajectory with a lower speed at the beginning of the motion, which can reduce the magnitude of the contact force.
Details
Keywords
The purpose of this paper is to study the lubrication characteristics of double involute gear (DIG), compare its lubrication differences under quasi-static and tribo-dynamic…
Abstract
Purpose
The purpose of this paper is to study the lubrication characteristics of double involute gear (DIG), compare its lubrication differences under quasi-static and tribo-dynamic conditions and study the influence of different factors on its lubrication characteristics under the tribo-dynamic condition.
Design/methodology/approach
According to the meshing characteristics of DIG and elastohydrodynamic lubrication (EHL) theory, a tribo-dynamic model of DIG is established based on the “subsection method.” The Runge-Kutta method and the multigrid method are integrated to solve the model, and the dynamic analytical model of lubricating oil is established in the iterative solution.
Findings
The load and the transmission error fluctuate obviously under the tribo-dynamic condition, which is not conducive to the lubrication of DIG. The influence of rotational speeds and torque on the lubrication properties of DIG has obvious differences under tribo-dynamic and quasi-static conditions.
Originality/value
This research can provide a theoretical basis for improving the lubrication performance, reducing the loss of mechanical efficiency and improving the bearing capacity and service life of DIG.
Details
Keywords
This paper aims to address how an organization's multiple-dominant-logic system evolves as it grows and how does this evolution affect the way managers choose to balance…
Abstract
Purpose
This paper aims to address how an organization's multiple-dominant-logic system evolves as it grows and how does this evolution affect the way managers choose to balance ambidextrous innovation.
Design/methodology/approach
This paper adopts an interpretive and exploratory case study on the mechanism of how the multiple-dominant-logic system influences the decision of balanced ambidextrous innovation. Considering that the multiple-dominant-logic system will change with the development of a firm, this paper focuses on exploring how the evolution of multiple-dominant-logic system affects the way managers choose to balance ambidextrous innovation. The authors spent almost two years collecting data from M-grass Ecology and following the evolution and innovation through semi-structured interviews, archival data and observation. Then they set up a framework showing the influence mechanism by analyzing the data through a four-step process.
Findings
This research points out that an organization's multiple-dominant-logic system may change for several times in its growth. It provides a model for the evolution of a multiple-dominant-logic system. It confirms that firms' multiple-dominant-logic system is not immutable, but evolves with the change of the firm's internal resources and external environment. Also, it finds that under the influence of different multiple-dominant-logic architectures, mangers choose different ways to balance ambidextrous innovation. In this process, appropriate entrepreneurial bricolage plays a significant role in balancing ambidextrous innovation.
Originality/value
The findings offer some valuable insights for further research on dominant logics and ambidextrous innovation and hold important implications for managers making a decision.