Impact Analysis of Transition between Semi-Rigid and Rigid Barriers Using Simulations

Transition is a type of barrier that connects other barriers with different grades and shapes. Even if each barrier satisfies the performance, it may not be satisfied in transition. Therefore, collision safety requires a special design and examination. In this study, we investigated national and foreign standards and situations for the proper configuration of the transition and analyzed the impact behavior of the general transition using impact simulations. We developed a transition system that could ensure the stable performance of various grades by analyzing the behavior and confirmed based on the full-scale crash test (SB2 level).

Collaborative optimization design of lightweight and crashworthiness of the front-end structures of automobile body using HW–GRA for Pareto mining

To collaboratively improve the lightweight and frontal collision safety performance of the automobile body, the material–structure–performance integrated multi-objective optimization design of the front-end structure was implemented in this study. The hybrid weight–grey relational analysis (HW–GRA) method was proposed to address the problem that the Pareto optimal compromise solution of multi-objective optimization cannot be easily selected. The design variables of the material and structural parameters were recorded through material type coding and model parameterization. To satisfy the basic static–dynamic performance constraints of the body, the RSM–Kriging surrogate model, design of experiments, and multi-objective particle swarm optimization algorithm were used to optimize the material and structural parameters to improve the lightweight and crashworthiness of the body. The Pareto optimal compromise solution was determined using the HW–GRA method. The decision result of the proposed method was more robust and rational than those of single weighting techniques combined with GRA and hybrid weighting approach combined with TOPSIS. After the multi-objective optimization and decision-making, the basic static–dynamic performance of the body demonstrated a change of less than 2.0%, which satisfied the constraint requirements. The mass of the body was reduced by 2.4 kg, and the frontal collision safety performance of the body was significantly improved.

Arrangement Optimization and Crashworthiness Analysis of B-Pilla Solder Joint Based on Collision Safety

Through hyperworks and Lsdyna, the side impact simulation of the vehicle model with Q&P980 class B-pilla is carried out. The middle part of B-pillar is the main part to bear the impact load, which corresponds to the occupant's chest and abdomen. The invasive displacement and the speed are large and the change trend is basically the same. After the optimization of the B-pillar weld solder joint layout, the number of solder joints was reduced by 23.61%, the structural static stiffness and the first-order torsional frequency were improved, the collision performance remained basically unchanged, and the body assembly cost was reduced.

Study on application of MSOT method for lightweight design of automobile body structure

In this study, the integrated MSOT (M-Multi-dimensional factor autobody model, S-Screening autobody component, O-Optimization of plate thickness, T-Testing, and validation) integration method is adopted to optimize the automobile body structure design for weight reduction. First, a multi-dimensional factor body model is established, then components of the vehicle are screened for the most important targets related to weight reduction and performance, and a multi-objective optimization is performed. Virtual experiments were carried out to validate the analysis and the MSOT method were proposed for lightweight design of the automobile body structure. A multi-dimensional performance model that considers stiffness, modality, strength, frontal offset collision, and side collision of a domestic passenger car body structure. Components affecting the weight of the vehicle were identified. Sheet metal thickness was selected as the main optimization target and a multi-objective optimization was carried out. Finally, simulations were performed on the body structure. The comprehensive performance, in terms of fatigue strength, frontal offset collision safety, and side collision safety, was verified using the optimized Pareto solution set. The results show that the established MSOT method can be used to comprehensively explore the weight reduction of the body structure, shorten the development process, and reduce development costs.

Importing the Human Factor into Safe Human–Robot Interaction Function Using the Bond Graph Method

SUMMARY The variable stiffness actuator (VSA) is helpful to realize the post-collision safety strategies for safe human–robot interaction.1 The stiffness of the robot will be reduced to protect the user from injury when the collision between the robot and human occurs. However, The VSA has a mechanism limit constraint that can cause harm to users even if the stiffness is minimized. Accordingly, in this article, a concept combining danger index and robust fault detection and isolation is presented and applied to active–passive variable stiffness elastic actuator (APVSEA). APVSEA can actively change joint stiffness with the change of danger index. Experimental results show that this concept can effectively confirm the fault mode and provide additional protection measures to ensure the safety of users when the joint stiffness has been adjusted to the minimum.

Safe Joint Mechanism using torsion springs for Collision Safety and Positioning Accuracy of a Robot Arm

In recent years, the potential for collision between humans and robots has drawn much attention since service robots are increasingly being used in the human environment. A safe robot arm can be achieved using either an active or passive compliance method. A passive compliance system composed of purely mechanical elements often provides faster and more reliable responses to dynamic collision than an active system involving sensors and actuators. Since positioning accuracy and collision safety of a robot arm are equally important, a robot arm should have very low stiffness when subjected to a collision force capable of causing human injury. Otherwise, it should maintain a very high stiffness. To implement these requirements, a novel safe joint mechanism (SJM-IV) consisting of a CAM, rotational links with rollers, and torsion springs is proposed. The SJM-IV has the advantage of nonlinear stiffness, which can be achieved only with passive mechanical elements. Various analyses and experiments on static and dynamic collisions show high stiffness of the SJM-IV against an external torque less than a predetermined threshold torque, with an abrupt drop in stiffness when the external torque exceeds this threshold. The safe joint mechanism enables a robot manipulator to guarantee positioning accuracy and collision safety, and which is simple to install between an actuator and a robot link without a significant change in the robot’s design.