An interactive data-driven driving simulator using motion blending

Compared to the motion equations the data-driven method can simulate reality from sampling of real motions but real-time interaction between a user and the simulator is problematic. Existing data-driven motion generation methods simply record and replay the motion of the vehicle. Character animation technology enables a user to control motions that are generated by a motion capture database and an appropriate motion control algorithm. We propose a data-driven motion generation method and implement a driving simulator by adapting the method of motion capture. The motion data sampled from a real vehicle are transformed into appropriate data structures called motion blocks, and then a series of motion blocks are saved into the motion database. During simulation, the driving simulator searches for and synthesizes optimal motion blocks from the motion database and generates motion streams that reflect the current simulation conditions and parameterized user demands. We demonstrate the proposed method through experiments with the driving simulator.     

一种用于AFS的半实物仿真平台

为了给自适应前照灯系统（Adaptive Front-Lighting System,AFS）提供一个控制算法验证平台,开发了一套基于汽车驾驶模拟器的AFS半实物硬件仿真平台。在该仿真平台中,PC机采集驾驶模拟器的档位、油门、离合、刹车、方向盘等驾驶信息,由车辆动力学模型模拟实际车辆行为,采用AFS控制模型计算车灯转角控制量,并发送至电机驱动模块进而控制车灯转动,同时将车灯转角信息反馈至PC机。实验表明,该系统能实时记录和显示AFS工作过程中的多种参数,便于进行实验观察和数据分析,从而为AFS系统的控制算法提供一个检验和修正的平台。     

Evaluation of driver’s behavior with multibody-based driving simulator

This paper deals with a driving simulator with a multibody vehicle model. Driving simulators require a real-time calculation of vehicle dynamics in response to driver’s inputs, such as a steering maneuver or a brake pedal operation. The authors realized a real-time calculation with a multibody vehicle model by approximating the calculation of constraint equations, and developed a driving simulator with 6-axes motion system. Drivers can feel the multibody analysis results through body sensory information such as the acceleration produced by the motion system and the visual information generated by computer graphics with the developed MBS simulator system. In this paper, a closed-loop test of a human-automobile system was investigated with the developed MBS driving simulator. In this evaluation, the driving simulator system and driver’s behavior were included in a multibody dynamics analysis, so it consists of a hardware- and human-in-the-loop simulation. It was observed from test results that the driving behavior was changed according to the parameters of the multibody vehicle model.     

Adequate motion simulation and collision detection for soccer playing humanoid robots

In this paper a humanoid robot simulator based on the multi-robot simulation framework (MuRoSimF) is presented. Among the unique features of this simulator is the scalability in the level of physical detail in both the robot’s motion and sensing systems. It facilitates the development of control software for humanoid robots which is demonstrated for several scenarios from the RoboCup Humanoid Robot League.Different requirements exist for a humanoid robot simulator. E.g., testing of algorithms for motion control and postural stability require high fidelity of physical motion properties whereas testing of behavior control and role distribution for a robot team requires only a moderate level of detail for real-time simulation of multiple robots. To meet such very different requirements often different simulators are used which makes it necessary to model a robot multiple times and to integrate different simulations with high-level robot control software.MuRoSimF provides the capability of exchanging the simulation algorithms used for each robot transparently, thus allowing a trade-off between computational performance and fidelity of the simulation. It is therefore possible to choose different simulation algorithms which are adequate for the needs of a given simulation experiment, for example, motion simulation of humanoid robots based on kinematical, simplified dynamics or full multi-body system dynamics algorithms. In this paper also the sensor simulation capabilities of MuRoSimF are revised. The methods for motion simulation and collision detection and handling are presented in detail including an algorithm which allows the real-time simulation of the full dynamics of a 21 DOF humanoid robot. Merits and drawbacks of the different algorithms are discussed in the light of different simulation purposes. The simulator performance is measured and illustrated in various examples, including comparison with experiments of a physical humanoid robot.     

Comparing a multiobjective optimization algorithm for discovering driving strategies with humans

When a person drives a vehicle along a route, he/she optimizes two objectives, the traveling time and the fuel consumption. Therefore, the task of driving can be viewed as a multiobjective optimization problem and solved with appropriate optimization algorithms. The comparison between the driving strategies obtained by humans and those obtained by the algorithms is interesting from several points of view. For example, it is interesting to see which strategies are better. To perform the human versus machine test, we compared the driving strategies obtained by the multiobjective optimization algorithm for discovering driving strategies (MODS) with those obtained by a group of volunteers operating a vehicle simulator. The test was performed using data from three real-world routes. The results show that MODS always finds better driving strategies than the volunteers, especially when the fuel consumption is to be reduced. Moreover, the results show that some volunteers always drive similarly in terms of traveling time and fuel consumption while others significantly vary their driving strategies.     

Role of lateral acceleration in curve driving: driver model and experiments on a real vehicle and a driving simulator

Experimental studies show that automobile drivers adjust their speed in curves so that maximum vehicle lateral accelerations decrease at high speeds. This pattern of lateral accelerations is described by a new driver model, assuming drivers control a variable safety margin of perceived lateral acceleration according to their anticipated steering deviations. Compared with a minimum time-to-lane-crossing (H. Godthelp, 1986) speed modulation strategy, this model, based on nonvisual cues, predicts that extreme values of lateral acceleration in curves decrease quadratically with speed, in accordance with experimental data obtained in a vehicle driven on a test track and in a motion-based driving simulator. Variations of model parameters can characterize "normal" or "fast" driving styles on the test track. On the simulator, it was found that the upper limits of lateral acceleration decreased less steeply when the motion cuing system was deactivated, although drivers maintained a consistent driving style. This is interpreted per the model as an underestimation of curvilinear speed due to the lack of inertial stimuli. Actual or potential applications of this research include a method to assess driving simulators as well as to identify driving styles for on-board driver aid systems.     

A 3D simulator for autonomous robotic fish

This paper presents a 3D simulator used for studying the motion control and autonomous navigation of robotic fish. The simulator's system structure and computation flow are presented. Simplified kinematics and hydrodynamics models for a virtual robotic fish are proposed. Many other object models are created for water, obstacles, sonar sensors and a swimming pool. Experimental results show that the simulator provides a, realistic and convenient way to develop autonomous navigation algorithms for robotic fish.     

Effects of uncoupled motion on performance

OBJECTIVES: To determine whether human exposure to vehicle motion specifically affects performance on a similar, yet uncorrelated, driving task and to observe the motion/simulator sickness symptoms that were associated with the real vehicle motion and the driving task. BACKGROUND: Past research has shown uncoupled motion can affect a person's performance on a task as well as induce motion sickness. METHODS: Ten participants (age range = 19-25 years) completed an uncorrelated driving task while seated in a stationary real vehicle and a moving real vehicle. RESULTS: The results show participants took longer to complete the motion condition, t(9) = 1.96, p < .05, and were less accurate, t(9) = 3.73, p < .05. Scores for the Motion Sickness Assessment Questionnaire, t(9) = 3.37, p < .05, and the Simulator Sickness Questionnaire, t(9) = 3.30, p < .05, were significantly higher during the motion condition. CONCLUSIONS: Performance on the task was degraded and motion sickness heightened during the motion condition. APPLICATION: This research has potential implications for military-related tasks such as operating a command and control station or controlling a remote vehicle while simultaneously being a passenger in a real vehicle, as well as for civilian applications such as interacting with a moving map navigation system while driving a car.     

Novel horseback riding simulator based on 6-DOF motion measurement,a motion base,and interactive control of gaits

This article describes the development process of a horseback riding simulator capable of generating a close to natural riding sensation. The development process started with 6-DOF motion measurement of the dynamics of the rider’s saddle during riding. Six-dimensional measurements during riding are required to fully understand the character of the saddle dynamics during different gaits. The measured quantities, i.e. translation accelerations and angular velocities, were transformed and filtered to form position references for a hydraulic Gough–Stewart platform. The presented novel motion measurement method is easy to use and makes it possible to measure gaits of several individual horses in a short time. It also provides a straightforward approach to produce motion data for the motion platform. In the second phase of the study, an artificial horse body made of glass fiber was mounted on the motion platform. The developed simulator realizes all three basic gaits walk, trot, and gallop. The rider is able to control the behavior of the simulator via sensors and an interactive interface. The control aids sensed by the interface are reins tension, calf pressure, and stirrup angle. A novel intelligent algorithm mimicking the real rider–horse interaction to vary the gaits and their frequencies was developed and tested.     

Development of a physiological knee motion simulator

Several kinds of knee motion simulator systems have been developed for the accurate analysis of knee biomechanics. Knee motion simulators, however, are not recognized for their practical use because of difficulties in design and control. In this study, a wire-driven knee simulator which generates physiological knee motion has been developed. Physiological three-dimensional tibia motion against the femur can be generated by the simulator. Many clinical studies have been performed to analyze the length displacement pattern of the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL). We assume that the physiological knee motion can be realized if the length displacement patterns of the ACL and PCL against the knee flexion angle are the same as the experimental data obtained from the literature. A fuzzy neural control policy, one of the most effective intelligent control policies, has been applied for control of the simulator. Applying the fuzzy neural control policy, human knowledge and experience can be reflected and adaptive/learning ability can be incorporated in the controller. On-line learning of the fuzzy neural controller is carried out to minimize a fuzzy controlled evaluation function using the back-propagation learning algorithm. The effectiveness of the proposed simulator has been evaluated by experiments using a model bone.     

MultiGen Creator/Vega在城市交通列车运行视景仿真系统中的应用

利用工具软件MultiGen Creator、Vega来实现实时视景仿真,介绍了工具软件MultiGen Creator和Vega的特点,探讨创建实时视景仿真的过程,并且结合轨道交通列车运行仿真视景的实例介绍了MultiGen Creator和Vega在虚拟现实技术中的具体应用.仿真结果表明,基于MultiGen Creator和Vega的轨道交通列车运行实时视景仿真系统取得了良好的效果,通过该仿真系统能够使学员在轨道交通列车行驶操控方面得到系统的培训和训练,而这无须到真正的列车上进行,从而保证了安全、缩短了学习时间并且降低了培训费用.     

Integrated Dynamics Control and Energy Efficiency Optimization for Overactuated Electric Vehicles

A large number of studies have been conducted on the dynamics control of electric vehicles or on the optimization of their energy efficiency but few studies have looked at both of these together. In this study, an integrated dynamics control and energy efficiency optimization strategy is proposed for overactuated electric vehicles, where the control of both longitudinal and lateral dynamics is dealt with while the energy efficiency is optimized. First, considering the trade‐off between control performance and energy efficiency, criteria are defined to categorize the vehicle motion status as linear pure longitudinal motion and non‐linear motion or turning motion. Then different optimization targets are developed for different motion status. For the pure linear longitudinal motion and cornering motion, the energy efficiency and vehicle dynamics performance are equally important and a trade‐off control performance between them needs to be achieved. For the non‐linear turning motion, vehicle handling and stability performance are the primary concerns, and energy efficiency is a secondary target. Based on the defined targets, the desired longitudinal and lateral tyre forces and yaw moment are then optimally distributed to the wheel driving and steering torques. Finally numerical simulations are used to verify the effectiveness of the proposed strategies. The simulation results show that the proposed strategies can provide good dynamics control performance with less energy consumption.     

Development of an Intelligent Wheelchair Using Computer Graphics Animation and Simulation

A new robot simulator JC-1 is used as a control software development tool in a project in progress where an intelligent wheelchair for a blind user is being developed. The intelligent wheelchair is planned to be able to fulfill simple symbolic commands like "follow wall" or "follow object" and using the JC-1 simulator an evaluation team which includes e.g. the user, a rehabilitation engineer and a software engineer, can check control algorithms and user interface routines before constructing a real wheelchair prototype. The JC-1 simulator models the environment using simplified boundary- representation where objects, robot sensors and actuators are presented as symbolic objects in the graphics data-base of the simulator. In the JC-1 simulator a robot controller under development controls the motion of the graphical model of the robot while simulator commands or other robot controllers can be used to control the movement of disturbing obstacles. Computer graphics animation and simulation help to find fundamental design errors at an early design stage and as this paper suggests, enable the user of the final product to take part in to the designing process of the robot controller. Benefits and difficulties of using computer graphics simulation in the wheelchair development process are discussed.     

Comparison of driving performance on-road and in a low-cost simulator using a concurrent telephone dialling task

Driving performance in an instrumented vehicle was compared with performance in a low-cost, fixed-based driving simulator. Six men and six women drove a freeway route while periodically dialling simulated phone calls. The same subjects drove a laboratory driving simulator using two visual fidelity levels: a colour scene with relatively high detail, and a monochrome (night) scene showing only road-edge markings. Lane position, speed, steering-wheel angle and throttle position were recorded in both contexts. Lane-keeping in the simulator was less precise than on the road, but speed control performance was comparable. The SD of lane position in normal driving was about twice as large, on average, in the simulator (0.360 versus 0.165 m). Lane keeping and speed control were less precise when dialling the phone than in normal driving, both in the simulator and on the road, but the performance decrement was greater in the simulator. The addition of the phone task increased the mean lateral speed in the car by about 43%, while in the simulator the mean lateral speed increased by 158% with the addition of the phone task. Subjects &gt;60 years of age showed larger performance decrements during a concurrent phone dialling task than did subjects 20–30 years of age both in the simulator and on-road. No important differences in driving performance were found between the high and low simulator scene fidelity levels. The simulator demonstrated good absolute validity for measures of speed control and good relative validity for the effects of the phone task and age on driving precision.     

基于深度时空Q网络的定向导航自动驾驶运动规划

针对目前基于机器学习的自动驾驶运动规划需要大量样本、没有关联时间信息,以及没有利用全局导航信息等问题,提出一种基于深度时空Q网络的定向导航自动驾驶运动规划算法。首先,为提取自动驾驶的空间图像特征与前后帧的时间信息,基于原始深度Q网络,结合长短期记忆网络,提出一种新的深度时空Q网络;然后,为充分利用自动驾驶的全局导航信息,在提取环境信息的图像中加入指向信号来实现定向导航的目的;最后,基于提出的深度时空Q网络,设计面向自动驾驶运动规划模型的学习策略,实现端到端的运动规划,从输入的序列图像中预测车辆方向盘转角和油门刹车数据。在Carla驾驶模拟器中进行训练和测试的实验结果表明,在四条测试道路中该算法平均偏差均小于0.7 m,且稳定性能优于四种对比算法。该算法具有较好的学习性、稳定性和实时性,能够实现在全局导航路线下的自动驾驶运动规划。     

IMPLEMENTATION OF A DRIVING SIMULATOR BASED ON A STEWART PLATFORM AND COMPUTER GRAPHICS TECHNOLOGIES

This paper describes works related to the development of a land vehicle driving simulator, which consists of a Stewart platform as its motion device and a computer graphical system as its visual component. The main task is to enable the pilot‐experience the sensation of motion while driving the vehicle under the constraint of the platform's finite working space. Involved are works such as establishment of the vehicle dynamical model, analysis of the forces acting on the pilot, and application of the washout algorithm and human motion sensation models. With the results from these works, appropriate motion trajectory commands for the platform can be generated. Besides the physical motion part, a computer graphical system is installed to generate scenes that give visual cues. While following the pilot's steering signals and matching the platform's motion, the visual system creates animation scenes of the environment, which are shown on a large screen in front of the pilot through an LCD projector. To test the completed system, different pilots operate it and give subjective assessments. Also, gyros are mounted on the platform to measure its responses to motion commands. Here some experimental results are summarized and discussed.     

大型运输机模拟器仪表系统①

目前模拟器仪表系统主要是实表系统,存在驱动复杂、价格昂贵等缺点。结合大型运输机综合训练器的研制,提出并采用了实物仪表与虚拟仪表相结合的飞机仪表系统,给出了实物仪表和虚拟仪表相结合的耦合仪表系统的实现方法,为飞机模拟器的仪表仿真提出了新的解决方案。     

汽车模拟器体感模拟滤波算法数字化实现

为在汽车模拟器上实现运动感觉,需要将汽车运动的线加速度、角速度参数通过体感模拟算法滤波处理.为满足编程要求,需将该算法经过数字化实现.根据经典体感模拟算法原理,针对大型特种车的运动特点,推导了体感模拟算法的滤波器传递函数及其阶次;采用双线性变换方法,将模拟滤波器的频率映射为数字滤波器频率,并将其传递函数推导为差分方程表达式,实现了数宁滤波.应用此数字滤波器对模拟信号和虚拟车输出的数字信号进行了滤波,结果表明该数字滤波器能够将高频与低频信号分离,并满足滤波精度和实时性要求,达到了预期的滤波效果.     

汽车驾驶模拟器脚踏板运动检测系统设计

该文针对当前汽车驾驶模拟器脚踏板运动检测系统存在的可靠性不高、不易维护等缺点,结合当前传感检测技术的发展趋势,从硬件和软件两方面分析并设计了一种基于光电传感技术的非接触式运动检测系统,并编写了单片机系统的相关程序及上位机的测试程序。