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在户外进行停车场车位检测容易受到不同外界因素的干扰,从而造成不必要的车位信息错误,给停车场的管理和停车用户带来诸多不便。针对这类户外停车场车位检测的实际要求以及对相关车位检测技术的研究,提出以基于巨磁电阻的车位检测技术作为核心检测技术,即汽车在停放或离开车位时使得地磁场与巨磁电阻之间磁场关系发生的变化来判断车位上车辆的变化,并且配套的设计了基于巨磁电阻检测的硬件系统和软件系统,分别用于停车位的车位检测和车位的显示,同时通过对巨磁电阻灵敏度的调节来更加灵活和准确地进行检测。试验结果表明,相比于其他车位检测技术该车位检测技术拥有更高精度和更强稳定性。 相似文献
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S. H. Jeong J. E. Lee S. U. Choi J. N. Oh K. H. Lee 《International Journal of Automotive Technology》2012,13(7):1133-1140
Recently, the advanced driver assistance system (ADAS), which helps mitigate car accidents, has been developed using environmental detection sensors, such as long and short range radar, lidar, wide dynamic range cameras, ultrasonic sensors and laser scanners. Among these detection sensors, radars can quickly provide drivers with reliable information about the velocity, distance and direction of a target obstacle, as well as information about the vehicle in changing weather conditions. In the adaptive cruise control system (ACCS), three radar sensors are usually needed because two short range radars are used to detect objects in the adjacent lane and one long range radar is used to detect objects in-path. In this paper, low-cost radar based on a single sensor, which can detect objects in both the adjacent lane and in-path, is proposed for use in the ACCS. Before designing the proposed radar, we analyzed the world-wide radar technology and market trends for ACCS. Based on this analysis, we designed a novel radar sensor for the ACCS using radar components, such as an antenna, transceiver module, transceiver control module and signal processing algorithm. Finally, target detection experiments were conducted. In the experimental results, the proposed single radar can successfully complete the detection required for the ACCS. In the conclusion, the perspective and issues in the future development of the ACCS radar are described. 相似文献
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B. J. Moon H. G. Jung S. G. Lee D. H. Kim 《International Journal of Automotive Technology》2014,15(3):483-494
This paper describes a parallel model-based fault detection algorithm for an electronic parking brake (EPB) system, which consists of an electronic control unit with built-in current sensor and braking force sensor. For the EPB system to supply sufficient parking force to a vehicle, the parking force sensor is of utmost importance. If a fault occurs in this sensor, sufficient parking force may not be supplied, thereby seriously threatening the safety of the vehicle. Thus, a fault detection method is required for the parking force sensor of the EPB system to improve the safety of vehicles. For this purpose, a highly reliable fault detection method is needed to detect abnormal fault signals, which cannot be detected by the existing on-line sensor monitoring fault detection methods. This paper proposes a novel parallel model-based fault detection algorithm for the EPB system, which compares the physical sensor data with the mathematical model, the fuzzy model, and the neural network model at the same time. In order to reduce false alarms, the magnitude of thresholds and the operation counts are changed adaptively. When the proposed parallel model-based fault detection algorithm detects severe failures of the force sensor, it warns the driver in advance to prevent accidents due to the failures. The proposed algorithm is verified by hardware-in-theloop simulations in various situations. 相似文献
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针对常见的平行泊车场景,提出一种基于自适应神经模糊推理系统的平行泊车路径规划方法。以基于优化算法的泊车路径规划方法得出的泊车路径作为训练样本,利用Python脚本语言建立以自适应遗传算法和拟牛顿法为内核的自动化训练框架,使自动训练后的自适应神经模糊推理系统既可继承基于优化算法的泊车路径规划方法适用范围更广的优势,又有效解决该方法求解过程计算量大的问题。通过仿真分析验证所提出方法的可行性和有效性,结果表明:自动训练后的自适应神经模糊推理系统可依据汽车初始泊车位姿和泊车位信息快速规划出可行的平行泊车路径。 相似文献
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This paper discusses the development of a system model for the wireless steering wheel angle sensor and steering wheel system
for the evaluation of the steer by wire system in a vehicle dynamic system. The steering wheel sensor is a wireless, contact-less
sensor utilizing an optical medium for angle detection. The optical medium is operated based on a photodiode and photo-detector
head. A reflecting disc or code-wheel, working similar to a compact disc, is used to reflect the light from the photodiode
back to the photo-detector. The beam is reflected based on the content in the reflective disc to measure the relative angle
through a micro-controller. The proposed wireless steering sensor and steer by wire system is modeled using the Matlab/Simulink
and their performance is investigated to evaluate the steering response, vehicle dynamics, and steering feel of the system.
Finally, the feasibility of the proposed system is discussed based on the developed model and simulation results. 相似文献
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The sideslip driving status is of fundamental importance to the stability of a vehicle. This paper presents a practical vehicle sideslip driving status estimation method that uses ESP (electronic stability program) sensors. ESP sensors such as wheel speed, lateral acceleration, yaw rate and steering wheel angle sensors are used to determine the sideslip driving status and distinguish a banked road. This estimation algorithm contains front-rear sideslip and banked road detection methods. The proposed sideslip estimation algorithm was designed to use the analytical redundancy of these sensors and Lagrange interpolation methods. The performance and effectiveness of the proposed estimation and compensation algorithm were investigated using vehicle tests. This paper presents the results of two cases that were used for the experimental verification: a curved flat road and banked road. 相似文献
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检测算法解决了现有地磁车位检测中无法排除邻位停车干扰以及所选判断标准无法适应多种车型、停车应用场景的问题.检测算法分析磁偶极子模型,基于矢量运算提取目标车位停车过程产生的地磁扰动矢量,有效排除邻近车位停车过程对目标车位磁场的影响.通过收集大量真实停车产生的地磁扰动信息,统计分析地磁扰动的强度以及方向变化特征,合理选取多级阈值作为算法中车位占用检测的标准,保证检测算法适用于多种车型、停车应用场景.经过3个月实地应用测试,发现检测算法车位占用检测精度达到99.3%,优于强度或者方向单一特征判断算法,并能检测出停车是否规范.研究算法尚未应用于大型客车、货车以及特种车辆车位占用判断. 相似文献
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针对智能汽车自动泊车系统的发展现状进行了分析,为解决泊车过程停车转向问题,提出一种连续曲率的平行泊车路径规划方案。对泊车环境进行分析,考虑汽车动力学约束条件,建立了自动泊车路径的约束空间,并根据对泊车路径的要求,在约束空间内生成合适的控制点,基于B样条理论生成可行的泊车路径。仿真结果表明,采用这种方法能够有效地实现避障,并且满足曲率连续性的要求,提高了自动泊车的灵活胜和连贯性。 相似文献
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L. Xiong G. W. Teng Z. P. Yu W. X. Zhang Y. Feng 《International Journal of Automotive Technology》2016,17(4):651-663
In this paper, a novel direct yaw control method based on driver operation intention for stability control of a distributed drive electric vehicle is proposed. It was discovered that the vehicle loses its stability easily under an emergency steering alignment (EA) problem. An emergent control algorithm is proposed to improve vehicle stability under such a condition. A driver operation intention recognition module is developed to identify the driving conditions. When the vehicle enters into an EA condition, the module can quickly identify it and transfer the control method from normal direct yaw control to emergency control. Two control algorithms are designed. The emergency control algorithm is applied to an EA condition while the adaptive control algorithm is applied to other conditions except the EA condition. Both simulation results and real vehicle results show that: The driver module can accurately identify driving conditions based on driver operation intention. When the vehicle enters into EA condition, the emergent control algorithm can intervene quickly, and it has proven to outperform normal direct yaw control for better stabilization of vehicles. 相似文献
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为了使全局路径与泊车路径无偏差对接,得到曲率连续的可行驶路径,为泊车模式切换提供精准位姿,提出基于拓扑地图的自主泊车路径协调与优化策略。首先,定义一种精简的停车场拓扑地图描述形式与道路拓扑设计原则,通过采集停车场内关键特征的定位数据建立停车场拓扑地图。其次,基于道路拓扑设计原则与泊车规划原则,设计“第1次平滑处理-路径协调-第2次平滑处理”的流程,对规划出的全局路径与泊车路径进行协调与优化。其中,“第1次平滑处理”利用对称极多项式,以车辆最小转向半径为约束,对全局路径的转折处平滑处理;“路径协调”通过节点替换的方式实现全局路径与泊车路径的无偏差对接;“第2次平滑处理”利用梯度下降的方法,分别优化前进段与倒车段的路径曲率,消除路径对接与均匀插值之后引起的曲率抖动。最后,在PreScan/Simulink联合仿真平台和实车试验平台上,验证路径协调与优化策略的有效性。研究结果表明:所提策略能够无偏差对接全局路径与泊车路径,并生成曲率平滑的可行驶路径,为横向控制提供了平滑变化的曲率值,有助于提高路径跟踪时转向的平稳性;在路径跟踪前为自主泊车控制系统提供了精准的泊车切换位姿,保证了低速自动驾驶与自动泊车之间的准确切换。 相似文献
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This paper presents a novel sensor-less steering torque control method for applications to the steer-by-wire system. A steer-by-wire system has not any mechanical link to connect a steering wheel and a rack and pinion gear module. Instead of mechanical devices, two electric motors are used on each side. A one motor is attached to the steering wheel and the other is set on rack and pinion. The motor on the steering wheel works as a deliverer between a steering torque and load torque from the road. In this paper, we focus on motion control related to the steering feel based on impedance control. Therefore, the model of rack and pinion is not considered in this work. In most power steering systems, a torque sensor is used to set impedance effect on driver’s steering feel. In this paper, we proposed a novel steering control method without using any torque sensors. The effectiveness of a proposed method is confirmed from experimental results. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(2):218-235
The structural characteristics and steering behaviour of a six-track vehicle are described in this paper. Kinematic analysis for skid steering of a six-track vehicle under steady-state conditions on firm ground is conducted, with the relationship between thrust force and speed instantaneous centre of the track–terrain interface taken into consideration. A mechanical model for steady steering of a six-track vehicle is also presented based on the kinematic analysis. In this model, the steering inaccuracy and efficiency are defined to evaluate steering performance. The steering performance of a six-track vehicle is numerically simulated to analyse the effect of the structural parameters and deflection angles on tracks. A virtual prototype model is established based on the multi-body dynamics software RecurDyn for steering simulation and the findings coincide well with theoretical results. The theory and the virtual prototype simulations presented are verified by a power test of a bucket-wheel excavator. The method for analysing the steering performance of a six-track vehicle proposed in this paper provides a basis for designing a six-track vehicle. 相似文献
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As driver assistant systems (DAS) and active safety vehicles (ASV) with various functions become popular, it is not uncommon
for multiple systems to be installed on a vehicle. If each function uses its own sensors and processing unit, it will make
installation difficult and raise the cost of the vehicle. As a countermeasure, research integrating multiple functions into
a single system has been pursued and is expected to make installation easier, decrease power consumption, and reduce vehicle
pricing. This paper proposes a novel side/rear safety system using only one scanning laser radar, which is installed in the
rear corner of the driver’s side. Our proposed system, ISRSS (integrated side/rear safety system), integrates and implements
four system functions: BSD (blind spot detection), RCWS (rear collision warning system), semi-automatic perpendicular parking,
and semi-automatic parallel parking. BSD and RCWS, which operate while the vehicle is running, share a common signal processing
result. The target position designation for perpendicular parking and parallel parking situations is based on the same signal
processing. Furthermore, as system functions during running and those during automatic parking operate in exclusive situations,
they can share common sensors and processing units efficiently. BSD and RCWS system functions were proved with 13025 and 2319
frames, respectively. The target position designation for perpendicular and parallel parking situations was evaluated with
112 and 52 situations and shows a success rate of 98.2% and 92.3%, respectively. 相似文献