This paper overviewed comprehensively the typical Active Collision Avoidance (ACA) systems and technological development, it firstly introduced the categories of ACA systems and its technical principle, then summed up the core key technologies of ACA system and technological level and summarized the mass-produced ACA products. The paper finally analyzed and predicted the development trend of ACA products.

In order to improve the energy utilization rate of composite power pure electric logistics vehicle, this paper optimized the existing composite power energy management strategy combined with the road slope. Firstly, a fuzzy controller which can automatically adjust the output power of supercapacitor based on different road slope coefficients was designed. Then Particle Swarm Optimization(PSO) algorithm was used to optimize the fuzzy controller. Finally, MATLAB/Simulink was used in CYC_UDDS to set different slopes for simulation verification under urban road conditions. The simulation results show that the proposed control strategy can reduce the energy consumption by 3.47%, 28.91% and 3.94% respectively on the fixed uphill, fixed downhill and the actual urban road slope, so it can give better play to the advantages of supercapacitor.

To solve the problems of matching omission and poor real-time performance of existing visual place recognition methods in scenes with changing viewpoints and environments, this paper proposed visual place recognition method based on one level feature fused with coordinate attention. Firstly, the relative place information of features was captured by coordinate attention. Secondly, an encoder for multi-scale feature fusion was constructed using dilated convolution and NetVLAD. Finally, the network was trained based on triplet loss. Validated by Pitts30k and Nordland datasets, the proposed method achieves the same recall accuracy and 19% faster retrieval speed compared with the state-of-the-art method Patch-NetVLAD of the same baseline in the test of position recognition. In the test of loop detection, the proposed method achieves a reasonable balance between robustness and retrieval speed.

In order to improve the safety of a commercial vehicle cab complying with the requirements of GB 26512—2011 real vehicle test and make it meet the requirements of GB 26512—2021, the Box-Behnken test design and Sequential Quadratic Planning (SQP) algorithm improvement were carried out for problems occurring in the cab simulation such as excessive peak force of longitudinal beam in frontal impact test, insufficient energy absorption in A-pillar impact test and serious crushing in side 20° impact test; and cab was optimized by setting bending beam and filling Expanded Polypropylene (EPP) foam material. The results show that after optimization, the longitudinal beam peak torque is reduced from 92.3 kN to 72.4 kN, the structural energy absorption is improved by 36.9%, the survival space is sufficient to meet the requirements of the new standards, and the cab safety is significantly improved.

In order to improve the safety of rear occupants with different sizes, this paper analyzed the damage of rear occupants in 100% frontal collision condition at 50 km/h by simulation. Firstly, a rear occupant restraint system model was established and verified. Then THUMS_AM50, THUNS_AF05 and CHARM-70 models were used to simulate different rear passenger sizes, Constant Loading Limit (Con-LL) curve, Progressive Loading Limit (Pro-LL) curve and Descending Loading Limit (Dig-LL) curve were respectively applied to explore the adaptability of seat belt loading curve to passengers of different sizes. The results show that the risk of neck ligament injury is great under this condition. The Dig-LL curve showed significant protection for the CHARM-70 but poor protection for the THUMS_AM50 during a frontal collision. Con-LL curve is not suitable for the protection of THUMS_AM50 and CHARM-70 under this condition. Pro-LL curves showed good protection for THUMS_AM50 and THUNS_AF05. In the future, the seat belt restraint system should be adapted to different loading curves according to the occupant type and collision condition to better protect the occupant.

To satisfy multiple objective performance requirements of B-pillar, a novel B-pillar with concave triangle Negative Poisson’s Ratio (NPR) cellular structure was designed. Firstly, the relative density equation of novel cellular structure can be derived by employing unit cell method. Then, quasi-static compression test was carried out on 3D printed cellular structure sample to verify the accuracy of finite element model. In addition, Genetic Algorithm (GA) was utilized to obtain the optimal structural parameters with the goals of maximum Specific Energy Absorption (SEA), minimum Peak Collision Force (PCF) and minimum relative density. Based on this, the thickness of B-pillar was optimized with the goal of minimum mass. Through analysis on 3 working conditions, it can be concluded that compared with the non-sandwich carbon fiber B-pillar, the backward bending displacement of the novel B-pillar decreases by 5.28%; compared with non-sandwich carbon fiber B-pillar and carbon fiber B-pillar, the lateral bending displacement of novel B-pillar decreases by 42.28% and 48.05% respectively, the maximum contact force of three-point bending increases by 80.08% and 12.63%, and the three-point bending displacement decreases by 0.02% and 2.14% respectively.

To study the influence of different service cycles of BioRID II dummy on test evaluation results in the whiplash tests, 4 whiplash tests are carried out by taking 2 dummies with different service cycle seating the H-point x at the baseline position +5 mm and -5 mm respectively, meanwhile, the dummy’s neck structure and calibration descriptions are discussed. The results show that the difference in service cycle between BioRID II dummy has significant influence on the Neck Injuries Criteria (NIC) and the lower neck axial force, and the gap in the whiplash test evaluation may reach more than 0.5. The rationality of the current way of adjusting the neck My and the method and dimension of dummy calibration remain to be discussed.

In order to explore the kinematic responses and injury mechanisms of far-end elderly occupants under the current Euro-NCAP side impact condition, a sled model was established using the elderly human body model CHARM-70, then the Advanced European Mobile Deformable Barrier (AE-MDB) side impact and oblique pole side impact finite element model were established, to conduct the vehicle collision simulation, and extract the acceleration pulse at the bottom of the B-pillar on the non-collision side. Finally, the single-occupant and double-occupant sled simulation models were established based on the THUMS_AM50_V4.0 human body model and the elderly human body model CHARM-70, to conduct the AE-MDB side impact and oblique pole side impact simulation. The results show that in the side impact, the seat belt can’t effectively limit the lateral offset caused by the inertia of the far-end occupant; in the single-occupant sled simulation, the head and neck injury values of the far-end elderly occupants are far less than the threshold, but the chest suffers serious rib fracture; in the double-occupant sled simulation, the far-end elderly occupants suffer severe head and chest injuries.

In order to study the feasibility of active-passive integration test based on acceleration sled, simulation and sled test were carried out on the 50th THOR dummy under 8.0 m/s² braking, and acceleration and deceleration simulation were carried out under frontal high-speed collision condition after AEB system braking. The results show that the occupant out-of-position fluctuates under AEB system braking, the maximum displacement occurs before the 300th ms, and the fluctuation range is small after the 400th ms. Under the simulation of acceleration sled, after the 400th ms, the protective effect of airbag on head and the stiffness performance of dummy chest are closer to the deceleration test. It therefore can be concluded that the active-passive integration test can be carried out on the acceleration sled by reducing the deceleration time of AEB under the circumstance of the reduced simulation time of AEB should not be less than 300 ms.

In order to improve the impact safety of integrated design of anti-collision beam, the multi-objective optimization model of anti-collision beam with crashworthiness and lightweight was transformed into game model and a mapping relationship was formed. The Specific Energy Absorption (SEA) and mass were taken as game parties, game distance and game moment were applied to establish the strategic attribution, and the model simulation was transformed into numerical optimization by combining the game utility function. The optimal solution was obtained through the Nash equilibrium analysis of the game utility function. The results show that the mass of the integrated anti-collision beam by the game design is reduced by 26.47% and SEA is increased by 22.18% compared with the initial design, and compared with the traditional optimization algorithm, the game design has better stability and optimization effect.