87 results about "Road surface roughness" patented technology

When a vehicle approaches a corner, a microprocessor, responsive to a determination that a detected degree of roughness of the road surface corresponds to the most moderate roughness, sets the damping force for the vehicle suspension units, on the basis of the detected degree of roughness, vehicle speed and a radius of curvature and corner information from a navigation system. In the case of a determination that the detected degree of roughness does not correspond to the most moderate roughness, a damping level is set on the basis of the detected degree of roughness, vehicle speed and radius of curvature.

Arrangement and method for determining weight of an occupying item in a seat including one or more weight sensors arranged to obtain a measurement of the force applied to the seat, a forcing function determination arrangement for measuring a forcing function of the seat and a processor coupled to the weight sensor(s) and forcing function determination arrangement for receiving the measurement of the force applied to the weight sensor(s) and the measurement of the forcing function from the forcing function measurement system and determining the weight of the occupying item based thereon. The forcing function determination arrangement may include an accelerometer and measures effects on the seat caused by load of a seatbelt associated with the seat and / or effects on the seat of road roughness, steering maneuvers, and a vehicle suspension system.

A digital lane mark generation apparatus of this invention generates a highly accurate and inexpensive three-dimensional mathematical expression orbit map (a digital lane mark), including a GPS coordinate reception unit 13 obtaining GPS coordinates (X, Y, Z) of the vehicle, a gyro sensor 14 calculating measurement values of a gradient (ψ, θ, φ), a camera device 19 photographing as a camera image, a distance meter 15 measuring a driving distance measuring point (1), a speed meter 16 measuring a speed(v), a steering angle sensor 17 measuring a steering angle (ρ), a road surface roughness sensor 18 detecting a road surface roughness (δ), an IC tag information reception unit 11 detecting IC tag position information; an internal timer 12a, and a digital lane mark generation unit 12 generating a digital lane mark by relating each information to a standard time (t), and by using a line segment (S), a circular arc (R), and / or a clothoid curve (A).

The invention relates to a quick road surface roughness detection system based on a vehicle-mounted accelerometer. The system comprises a three-axis acceleration sensor, an angular velocity sensor, a Zigbee short-range wireless communication module, a touchable vehicle-mounted terminal, a GPS (global positioning system) and a central computer information processing system, wherein the Zigbee short-range wireless communication module and the three-axis acceleration sensor are integrated to form data acquisition equipment, and the data acquisition equipment is used for acquiring acceleration values produced during riding of a vehicle and performs internal short-range wireless transmission; the GPS, the angular velocity sensor and a 3G remote module are used for recording geographic coordinates of the riding vehicle and turn angle conditions of the riding vehicle and transmit packed files to a server; the touchable vehicle-mounted terminal is used for acquiring acceleration sensor data and matching the acceleration sensor data with GPS data and angular velocity data by using a time sequence to generate initial data; the central computer information processing system is used for directionally receiving data sent by the to-be-detected vehicle and processing the data to acquire an estimated IRI (internal roughness index) / RQI (riding quality index) to be displayed on an electronic map. The system is used for solving problems that traditional detection methods are time-consuming, labor-consuming, low in efficiency, high in price and the like and monitors the road surface roughness in real time.

An intelligent system and method detects and informs operators of unstable vehicle conditions. An accelerometer and gyro based micro-controller system dynamically computing the center of mass, speeds, positions, angles, stability factors, Velocity-Road Roughness Index, Dynamic Stability Function, and other parameters critical in determining the dynamics of vehicle motion. The apparatus may be integrated into an overall vehicle network and may incorporate a method for detecting and warning vehicle operators of unstable driving conditions which may include rollover, high velocity turns, sideslope conditions, rough roads, slip, and other dynamic events.

The invention discloses a three-dimensional road surface elevation data generation method for vehicle dynamics research. The method comprises the following steps of: 1, comparing a road surface roughness power spectrum density power function expression specified by a national standard by a least square nonlinear parameter estimation method to obtain parameters in a road surface roughness power spectrum density rational function expression; 2, extending a one-dimensional power spectrum density rational function expression to acquire two-dimensional power spectrum density, and establishing a three-dimensional road surface elevation mathematical model based on a two-dimensional inverse flourier transform method according to the two-dimensional power spectrum density; and 3, programming in a matrix laboratory (MATLAB) according to the mathematical model obtained in the step 2, and generating three-dimensional road surface elevation data according to required road surface level, road length, width and sampling interval. By the method, the road surface elevation data is quickly generated, power spectrum characteristics of a straight track and a bent track of a road surface are excellent, and the generated data can replace data which is manually measured on site; and the method is suitable for vehicle dynamics research of dynamics software and a virtual prototype of a vehicle.

Direct sensing of rough road conditions are used to modify operation of a wheel slip control system. At least one suspension sensor (139) senses an operating parameter of the suspension system. A road surface classifier is responsive to the suspension pension sensor (139) for generating a road surface signal representing a roughness of a road surface over which the vehicle travels. A braking system includes a wheel speed sensor and a brake actuator. An active braking control detector wheel slip in response to the wheel speed sensor (108) during at least one of braking or accelerating of the vehicle and modulates the brake actuator in response to the detected wheel slip. The active braking control is responsive to the road surface signal for modifying modulation f the brake actuator as a function of the road surface signal.

The invention relates to a motion planning method considering a three-dimensional terrain, in particular to motion planning of an unmanned vehicle in the three-dimensional terrain, and belongs to the field of unmanned vehicle motion planning. In order to ensure the driving safety of an unmanned vehicle on a three-dimensional terrain surface and enhance the reasonability of motion planning in the three-dimensional terrain, the invention provides a motion planning method for ensuring the safe driving of the unmanned vehicle on the three-dimensional terrain. The main content is divided into four parts, and the terrain environment representation and pose projection method is the basis of subsequent operation. The terrain trafficability discrimination algorithm considers the influence of the road surface roughness and the ground shape on the trafficability, and ensures the static stability of the vehicle. The three-dimensional terrain path planning comprises two steps of reference path generation and traceable path generation. The speed planning comprises two steps of initial speed curve generation and speed curve smoothing.

The invention discloses a road condition simulation loading test device and a test method for a driving motor of an electric vehicle. The test device is composed of a strain torque speed sensor, a speed reducer, a transmission device, tires, a power motor, a lifting device and a detection control cabinet. The transmission device, the tires and the power motor constitute a loading platform to simulate various road conditions; a motor lifting platform adjusts the height of the motor; and a computer adjusts the road conditions simulation loading platform to realize realistic road surface simulation on the motor to be tested under different weather, different roughness and different driving modes. By simulating a road with conveyor belts, simulating road roughness with change of the conveyor belts, simulating road slope with lifting adjustment of contact angle between the tires and the conveyor belts through a lifting transmission device and simulating different weather conditions with change of force applied by the power motor, a user inputs road conditions, collects motor power and speed data, processes the data and forms a graphical report to intuitively reflects the performance parameters of the motor and simulated loading effects under different road conditions.

The invention relates to a non-contact pavement roughness measurement apparatus and method for measuring pavement roughness with non-contact mode, especially relates to a non-contact pavement roughness measurement apparatus for quantificationally representing pavement roughness by representing data acquired by illuminating laser beam to the pavement as phase value, and carrying out non-contact measurement such that the pavement can be measured quickly, and method thereof.

A manually operated portable device for comparing tire to pavement skid resistance under different tire to road contact conditions, wherein such device can be used at any location on any pavement type without the need for initial settings. The device can test various parameters, including the effect of tire material on skid resistance, the effect of pavement material, the effect of pavement surface roughness, and the effect of pavement surface conditions, as well as the coefficient of friction. The device may include a plurality of rotating arms, a plurality of shoe assemblies, a central shaft, a stabilizing weight, a square-sectioned shaft, a spring, a handle, and an angular scale.

The invention discloses a dynamic traffic flow based forecast method of noise in the peripheral zone of a long straight road. According to the method, a microcosmic moving trajectory of a vehicle in a road section is defined accurately, a vehicle source emission model is established, a noise transmission model is established simultaneously, and a complete set of noise forecasting method is obtained. The forecast method comprises steps as follows: (1), dynamic traffic flow simulation vehicle models at a forecast location are classified, and a dynamic traffic flow simulation model is established; and (2), reference radiation sound levels of different vehicle models are determined, meanwhile, traffic composition, range attenuation and noise barrier insertion loss are considered to calculate forecast sound level of the noise, and the forecast sound level is amended with consideration of surface roughness, the slope and the roadside ground type. According to the forecast method, limitation of the conventional noise forecast method is broken through on the basis that correlation research ideas of other subjects are absorbed sufficiently, and the sound level of the noise in a sensitive area can be forecast accurately.

The invention discloses a road surface roughness monitor. The road surface roughness monitor comprises a vehicle mounted terminal, an acceleration sensor, a temperature sensor, a compactness detector, video collecting equipment, a liquid crystal display module, an alarm module, a GPRS (General Packet Radio Service) radio module, a GPS (Global Positioning System) receiver, a power supply module, a field computer monitoring terminal, a central computer monitoring terminal and a hand-held terminal. According to the road surface roughness monitor disclosed by the invention, rolling speed, rolling temperature and compactness information of a road roller in the asphalt road surface rolling process are collected by the acceleration sensor, the temperature sensor, the compactness detector and the video collecting equipment; and monitoring personnel can remotely monitor the road roller to roll the asphalt road surface in real time so that the asphalt road surface rolling quality of the road roller is guaranteed.

The invention discloses a vehicle operation control method based on automatic driving. The method comprises the following steps: acquiring state information of a road ahead of the running of the vehicle through a vehicle external sensor, wherein the front road state information include an adhesion coefficient, road surface roughness, curve radius and gradient of the front road; calculating a stable driving envelope of the vehicle when the vehicle drives on the front road according to the state information of the front road, wherein the stable running envelope includes a maximum vehicle speed and a steering angle that satisfy the stable running of the vehicle; and controlling the vehicle to run at a first vehicle speed and a first steering angle when the vehicle automatically runs to the front road according to the stable running envelope, wherein the first vehicle speed and the first steering angle meet the vehicle stable running requirement. The method realize estimating of the road surface state in advance, so that the probability of the automatic driving vehicle entering the unstable state is reduced, and the driving safety is improved.

A vehicle includes a radar sensor for detecting objects in the vehicle path. The radar sensor may become blocked by contaminants or debris. A controller monitoring the radar system may detect a radar blockage when a return signal magnitude is less than a threshold. A typical response may be to set a radar blockage diagnostic under such a condition. The controller may inhibit setting a radar blockage diagnostic when other data indicates that the radar sensor is not blocked. Data such as vehicle position, traffic information, camera images, and historical radar returns may be used. A controller may confirm a radar blockage diagnostic when other data indicates that the radar sensor may be blocked. Data such as temperature, vehicle position, surface roughness, automated brake interventions, and heating system status may be used. Return signal dependent functions may be operated based on the radar blockage diagnostic.

The invention provides a transition structure for preventing and treating bump at bridge-head and a construction method thereof. The structure of the transition structure for preventing and treating the bump at the bridge-head comprises a beam body; bridge abutments are fixedly mounted at the two ends of the beam body; one ends of towing plates are fixedly mounted at the middle parts of the bridgeabutments; the other ends of towing plates are buried in a subgrade; the parts behind the bridge abutments and the upper parts of the towing plates are filled with backfilled earth; combined approachslab members are laid on the upper surface of the backfilled earth; and one ends of the combined approach slab members are fixedly mounted on the external sides of the upper ends of the bridge abutments. The construction method comprises the steps of erecting the bridge abutments molded with brackets, constructing the towing plates on the brackets to form two layers of backfill structures, and arranging the combined approach slab members to improve a bearing structure; and therefore, road surface roughness and breakage at the bridge head connecting part caused by uneven settlement of the backfilled earth in the using process are reduced to realize an effect of preventing and treating the bump at the bridge-head; and meanwhile, through the structure combination, energy saving and environmentally friendly properties are realized, the construction period is shortened, template members are saved, and accuracy and quality are very well guaranteed.

The invention provides a pavement roughness measuring method and a pavement roughness measuring device. The pavement roughness measuring method comprises steps that a pavement image is acquired; the graying processing of the pavement image is carried out to acquire a gray-scale image of a pavement; the two-dimensional sampling of the gray-scale image is carried out to acquire the two-dimensional sampling point of the gray-scale image; the gray-scale data of the gray-scale image is acquired; the three-dimensional grid image of the pavement image is acquired according to the two-dimensional sampling point and the gray-scale data of the gray-scale image; the pavement roughness is acquired; The pavement roughness measuring method and the pavement roughness measuring device are used to measure the cement concrete pavement roughness, and by adopting the above mentioned method, the result of measuring the cement concrete pavement roughness is stable, and on-site fast sampling is realized during outdoor measurement, and only later indoor analysis and calculation are required.

The invention discloses a road surface roughness prediction method based on random forest. The road surface roughness prediction method based on the random forest comprises the following steps that S1, for each asphalt road surface, values of a road surface roughness index IRI and road surface parameters are collected, and asphalt road surface sample data are obtained; S2, each road surface parameter is normalized to obtain a training set; S3, the training set is trained through a random forest algorithm, the road surface roughness indexes IRI are used as the output of the random forest algorithm, the road surface data are used as the input, and a trained asphalt road surface roughness prediction model is obtained; S4, road surface parameter values of a to-be-measured asphalt road surfaceare collected, and to-be-measured asphalt road surface data are obtained; S5, normalization operation is performed; and S6, the to-be-measured normalized asphalt road surface data are processed by using a trained asphalt road surface roughness prediction model, and the road surface roughness of the to-be-measured asphalt road surface is obtained. According to the road surface roughness predictionmethod based on the random forest, the road surface roughness prediction model based on the random forest is established, and the prediction precision of the road surface roughness can be greatly improved through the model.

A vehicle road simulation system is disclosed. The system comprises a road simulation test system and a test vehicle. The test vehicle comprises a test power assembly, a vehicle body structure and a chassis system. The test power assembly comprises a test transmission, a test power source and a test clutch. The chassis system comprises a power assembly suspension system and other chassis structurecomponents. The parameters of the test power assembly and an actual vehicle power assembly are the same. When the test clutch is closed, the road simulation test system outputs an acting force to thetest power assembly through motion. The acting force simulates the acting force generated by the random vibration of the power assembly caused by road surface roughness and the acting force generatedby the output of a test power source torque to the power assembly suspension system. In the above scheme, power assembly suspension load accuracy simulation can be realized, and simultaneously, the complexity of the vehicle road simulation system is reduced.

A physical layer secret key generation scheme exploiting randomness of the road surface and driving behavior is described herein. A symmetric key generation scheme can be implemented in any existing V2V visible light communication. By analyzing and simulating numerous samples taken from NGSIM vehicle trajectory data, the natural driving behavior and road surface roughness can be exploited as a source of randomness to generate symmetric cryptographic security keys.

The invention discloses an unstructured road state parameter estimation method and system, and the method comprises the steps: 1, carrying out the time synchronization and space synchronization of collected point cloud data and image data, and obtaining a mapping relation between a point cloud in the point cloud data in a laser radar coordinate system and a pixel in a pixel coordinate system; 2, performing multi-sensor fusion ground segmentation, and outputting a point cloud ground segmentation result and an image ground segmentation result; step 3, enhancing ground point cloud data; 4, road adaptive block fitting is carried out, and road surface modeling is realized; step 5, estimating road parameters: based on a pavement plane model, calculating a normal vector included angle of two adjacent planes to obtain relative longitudinal / transverse gradients of the adjacent planes; the distance between the ground point cloud and the corresponding fitting plane is calculated, and the root mean square of the distance is used as an evaluation index of the pavement roughness; and performing road curvature estimation by fitting the road boundary of each block plane.

The invention discloses a hydro-pneumatic suspension hydraulic system. The hydro-pneumatic suspension hydraulic system comprises hydro-pneumatic springs and hydraulic control elements; each hydro-pneumatic spring comprises an energy accumulator, a throttle valve and the like; and each hydraulic control element comprises a backpressure valve, a hydraulic pump, a filter, an oil tank and the like. According to the characteristics of nonlinearity, variable stiffness, variable damping and the like of the hydro-pneumatic suspension system, single-way valves, the throttle valves and two-position two-way electro proportional valves are arranged outside suspension cylinders correspondingly, the positions of valve cores are changed by controlling the electric current flowing through the two-position two-way electro proportional valves, further the through-flow areas of valve openings are changed, and accordingly the size of damping can be adjusted timely according to the road surface roughness, and the smoothness and the control stability of a vehicle are improved to reach optimum matching so that semi-active control over a hydro-pneumatic suspension can be achieved easily; and meanwhile, the functions of adjusting the vehicle attitude, shutting the vehicle and the like can be achieved by controlling opening and closing of two-position two-way electromagnetic reversing valves and three-position four-way electromagnetic reversing valves, and accordingly the trafficability of the integral vehicle is improved, and the different requirements for rigid operation and flexible driving are met.

The invention discloses a vehicle-mounted laser pavement point cloud thinning method capable of reserving spatial characteristics. Firstly, preprocessing such as denoising and missing interpolation iscarried out on road surface point cloud; establishing a multi-scale grid for the pavement point cloud data, constructing a spatial hybrid index in combination with a KD tree, and quickly constructinga k neighborhood topological relation of data points; performing weighted principal component analysis and least square surface fitting on k neighborhoods of the data points, calculating a feature description subset, constructing a multi-feature description model by utilizing the feature description subset, performing pavement roughness analysis, and adaptively extracting pavement internal damagefeature points; extracting global edge feature points of the pavement by utilizing a distribution uniformity constraint method of the point cloud; and finally, for a non-feature region, performing secondary thinning by using a uniform grid gravity center method, and fusing the point cloud after secondary thinning with the feature points to complete thinning.

The invention provides a pavement roughness identification method and apparatus. The pavement roughness identification method includes the steps: sampling at least one front-axle axle-height displacement, wherein one sampling time is corresponding to one front-axle axle-height displacement; determining the front-axle axle-height displacement difference corresponding to each sampling time; according to the front-axle axle-height displacement difference corresponding to each sampling time, determining the number of the front-axle axle-height points of inflexion on curve, and the sum of front-axle axle-height curve amplitudes; according to the front-axle axle-height displacement corresponding to each sampling time, determining the front-axle axle-height curve fitting slope and the front-axle axle-height curve fitting variance; respectively performing fuzzy processing on the number of the front-axle axle-height points of inflexion on curve, the sum of front-axle axle-height curve amplitudes, the front-axle axle-height curve fitting slope, and the front-axle axle-height curve fitting variance so as to obtain the roughness after fuzzy processing; and determining the pavement roughness according to the roughness after fuzzy processing. The pavement roughness identification method and apparatus can improve the identification accuracy for the pavement roughness and can reduce the use cost.

The invention discloses an automatic collection method of a three-dimensional road surface information spectrum, which is applied to a vehicle comprising a suspension mechanism and an information collection mechanism and comprises the following steps: 1, collecting vertical road surface information data; 2, obtaining an output variable of the kth cycle according to the quarter vehicle suspension two-degree-of-freedom kinetic model; 3, calculating the pavement relative roughness and the power spectral density of the kth cycle; 4, calculating an estimated pavement roughness result of the kth cycle; 5, obtaining the pavement relative roughness of the (k + 1) th cycle based on the discrete Kalman filtering prediction model; 6, calculating a pavement adhesion coefficient; and 7, coupling the road surface relative roughness and the road surface adhesion coefficient by using the timestamp of the positioning coordinate to obtain a road surface information spectrum of the kth cycle. According to the invention, road surface information can be collected by using the existing suspension structure and the sensor thereof, so that the road surface information spectrum can be quickly and accurately established at low cost.

In a wheel position detection apparatus, a first control unit (23) of a transmitter (2) repeatedly transmits a frame including unique identification information at the timing when the angle of the transmitter (2) is at a predetermined angle. A second control unit (33) of a receiver (3) receives the frame transmitted from the transmitter (2), and identifies which of a plurality of wheels (5a to 5d) the transmitter (2) that has transmitted the frame is attached to. The receiver (3) modifies an allowable variation range in accordance with a road surface condition expressed by the degree of road surface roughness each time the frame is received, and sets the allowable variation range wider for a rough road surface than for a smooth road surface.

The invention provides a bridge floor roughness identification method based on two-connected measurement vehicle contact point displacement influence lines. According to the strategy of the method, vertical displacement of a bridge is eliminated from vehicle response, so that pure road surface roughness information is obtained, and precise identification of the bridge surface roughness is achieved. The core thought is as follows: based on an influence line principle and the space position relationship of front and rear vehicles, an approximate correlation relationship (defined as a static correlation coefficient) of bridge vertical displacement u1(x-d) and u2(x-d) at a contact point of the front vehicle and the rear vehicle is established, and an additional constraint condition can be provided for decoupling of the bridge vertical displacement and the bridge floor roughness, so that the bridge vertical displacement is eliminated from responses of the front vehicle and the rear vehicle,and the purpose of precisely identifying the road surface roughness is achieved. The method can replace traditional and expensive instruments and equipment, realizes rapid detection of bridge pavement conditions, and effectively avoids traffic jam caused by road closure operation.

The invention discloses a method for acquiring an impact coefficient of a simply supported girder bridge, which comprises the following steps of converting a pavement roughness spectrum of the simply supported girder bridge into a pavement roughness spectrum expression taking time frequency as a variable according to a single free vehicle system with a known speed; calculating the power spectrum density of vibration response of the vehicle system under the action of the pavement roughness spectrum according to the mass, rigidity and damping of the single-free vehicle system, and obtaining the random acting force spectrum of the simply supported girder bridge according to the power spectrum density; constructing a random process according to the random acting force spectrum of the vehicle, and converting the random load of the vehicle system into a series expansion of a time-frequency domain; performing modal decomposition on the motion equation of the simply supported girder bridge, and solving the modal motion equation of the simply supported girder bridge under the action of the moving random load by utilizing a trigonometric function product sum-difference method to obtain a probability statistical characteristic value of the dynamic response of the simply supported girder bridge; and calculating the ratio of the root variance of the vibration response to the maximum static response to obtain the impact coefficient of the simply supported girder bridge.