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Concerns about the risk of traffic collision injury to both police officers and bystanders are increasing as the use of in-vehicle technologies becoming widespread among agencies. This study used national and California data to characterize traffic collisions in which a police vehicle was involved. The paper aims to discuss these issues.

The authors used a California traffic collision database to retrospectively identify collisions that involved police vehicles for years 2007-2010. The authors summarized collision characteristics with descriptive methods and used log-binomial regression to estimate associations between personal and collision characteristics with officer culpability.

The authors identified 5,233 traffic collisions in California. In total, 10 percent of law enforcement vehicles were motorcycles. In all, 9 percent of cruisers struck a pedestrian or bicyclist, compared with only 2 percent of motorcycles. Compared with officers aged 50 or older, officers in younger age categories were progressively much more likely to have been culpable. Motorcycle officers were 33 percent less likely to be culpable for their collision involvements. Approximately 100 fatal collisions involving a law enforcement vehicle occur each year in the USA.

The findings from this study indicate that approximately 1,300 injury-producing traffic collisions occur each year in California that involve a law enforcement vehicle. The authors found that younger age, female sex, cruiser operation, traveling unbelted, and single-vehicle collision involvement were positively associated with officer culpability. Officer race and community population were not significantly associated with culpability. The occurrence of fatal collisions in the USA was stable over a 12-year period.

This paper presents a new technique for collision detection between fabric and fabric or fabric and body, applied on our physical‐based fabric drape model. The technique can produce a realistic 3D virtual fashion show based on fabric mechanical properties and has the ability to handle the collision of clothing with an animated synthetic human. The collision technique appeared efficient and reliable when dealing with complex cases of fabric deformation. A full implementation of the drape model, collision detection with an animated human model is also described and discussed.

Aims to make an industrial robot work human‐friendly while coexisting with humans in a same working space, without any modification of the manipulator hardware as well as its motion controller.

Presents a weighted path planning approach based on collision detection for a robot sharing the same workspace with humans. Using a base and wrist force/torque sensors, a model‐based method is investigated to estimate the collision force and collision position on the manipulator; then a weighted path planning approach is developed to control the human‐robot interaction. Simulation experiments, with collisions between the manipulator and static objects and moving objects, are conducted to validate the efficacy of the method.

The experimental results illustrate the validity of the developed collision detection and planning scheme and make it possible for industrial robots to work safely around humans. The proposed weighted path planner (WPP) outperforms other three path planners.

Introduces the WPP based on collision detection. The wrist and base force/torque sensors configuration has the friction free benefit, and the developed method does not modify the existing designs of industrial robots. The contact force is well controlled under the human pain tolerance limit, through the modification of the desired path, and does not need torque control which is usually not available to industrial robots.

The purpose of this paper is to develop a new and simple methodology for fabric collision detection and response.

A 3D triangle‐to‐triangle collision problem was converted to simple 2D point‐in‐triangle problem using pre‐computed 4×4 transformation matrices. The object space was partitioned using voxels to find easily collision pair triangles. k‐DOP was used to find inter‐pattern collisions.

Complex 3D collision detection problem is solved by simple matrix operations. Voxel‐based space partitioning and k‐DOP‐based hierarchical methods are successfully applied to garment simulation.

This paper shows that the collision matrix method can cover from triangle‐to‐point to triangle‐to‐triangle collision with mathematical validity and can be simply implemented in garment simulation.

This paper aims to use redundant manipulators to solve the challenge of collision avoidance in construction operations such as welding and painting.

In this paper, a null-space-based task-priority adjustment approach is developed to avoid collisions. The method establishes the relative position of the obstacle and the robot arm by defining the “link space,” and then the priority of the collision avoidance task and the end-effector task is adjusted according to the relative position by introducing the null space task conversion factors.

Numerical simulations demonstrate that the proposed method can realize collision-free maneuvers for redundant manipulators and guarantee the tracking precision of the end-effector task. The experimental results show that the method can avoid dynamic obstacles in redundant manipulator welding tasks.

A new formula for task priority adjustment for collision avoidance of redundant manipulators is proposed, and the original task tracking accuracy is guaranteed under the premise of safety.

The safety performance of cooperative robots is particularly important. This paper aims to study collision detection and response of cooperative robots, which meet the lightweight requirements of cooperative robots and help to ensure the safety of humans and robots.

This paper proposes a collision detection, recognition and response method based on dynamic models. First, this paper identifies the dynamic model of the robot. Second, an external torque observer is established based on the model, and a dynamic threshold collision detection method is designed to reduce the interference of model uncertainty on collision detection. Finally, a collision position and direction estimation method is designed, and a robot collision response strategy is proposed to reduce the harm caused by collisions to humans.

Comparative experiments are conducted on static threshold and dynamic threshold collision detection, and the results showed that the static threshold only detected one collision while the dynamic threshold could detect all collisions. Conducting collision position and direction estimation and collision response experiments, and the results show that this method can determine the location and direction of collision occurrence, and enable the robot to achieve collision separation.

This paper designs a dynamic threshold collision detection method that does not require external sensors. Compared with static threshold collision detection methods, this method can significantly improve the sensitivity of collision detection. This paper also proposes a collision position direction estimation method and collision separation response strategy, which can enable robots to achieve post collision separation and improve the safety of cooperative robots.

This paper uses numerical methods to investigate the collision and skidding of rolling elements in a cageless ball bearing. This paper aims to analyse the effects of the rotational speed and number of rolling elements on the rolling element collision and skidding.

Based on Hertzian theory and tribological theory, the collision contact model of the rolling element was established. Based on the proposed model, the differential equations of motion of the two degrees of freedom rolling element were constructed. The fourth-order Adams algorithm solved the collision contact force between the rolling elements. The sliding velocity between the rolling element and the inner and outer races was calculated.

The collision frequency and slip of rolling elements can be reduced by increasing the rotational speed appropriately and reducing the number of rolling elements by one.

The developed model can reveal the collision and slip characteristics of the rolling elements for cageless bearings. This study can provide theoretical guidance for the design and manufacture of cageless ball bearings.

The purpose of this paper is to conduct a survey on research in fabric and cloth simulation using mass spring model. Also in this paper some of the common methods in process of fabric simulation in mass spring model are discussed and compared.

This paper reviews and compares presented mesh types in mass spring model, forces applied on model, super elastic effect and ways to settle the super elasticity problem, numerical integration methods for solving equations, collision detection and its response. Some of common methods in fabric simulation are compared to each other. And by using examples of fabric simulation, advantages and limitations of each technique are mentioned.

Mass spring method is a fast and flexible technique with high ability to simulate fabric behavior in real time with different environmental conditions. Mass spring model has more accuracy than geometrical models and also it is faster than other physical modeling.

In the edge of digital, fabric simulation technology has been considered into many fields. 3D fabric simulation is complex and its implementation requires knowledge in different fields such as textile engineering, computer engineering and mechanical engineering. Several methods have been presented for fabric simulation such as physical and geometrical models. Mass spring model, the typical physically based method, is one of the methods for fabric simulation which widely considered by researchers.