CATARC AUTOMOTIVE TEST CENTER (TIANJIN) CO., LTD

A low scattering turntable for improving quiet zone test performance and a quiet zone test method is provided, and relates to the technical field of quiet zone test. The low scattering turntable includes an L-shaped baffle, a rhombic inclined wedge supporting column, a bottom plate, a turntable base, a fixed block, a longitudinal rotating shaft and a transverse rotating shaft. In the disclosure, the rhombic inclined wedge supporting column is adopted, the sharp wedge diffraction and traveling wave scattering effects are reduced. Multi-layer side wave-absorbing materials layout are used in the rhombic inclined wedge supporting column, which can effectively reduce electromagnetic reflection and scattering in a wide frequency range. By adding sawtooth wave-absorbing material to the edge of L-shaped baffle, the reflection intensity of electromagnetic wave is reduced and the overall wave-absorbing efficiency is improved. The oval bottom plate is adopted to reduce the measurement error.

A method for measuring motion postures of lower limbs of an automobile collision dummy continuously collects lower limb images of the automobile collision dummy during a collision in a real automobile collision test; identifies an edge contour in each lower limb image; samples a plurality of points from the edge contours for fitting to obtain a lateral thigh expression, a lower medial thigh expression, a lateral lower leg expression, and a lower medial leg expression respectively; determines various bone positions, various joint positions, and various bone angles of each lower limb; and associates the various bone positions, the various joint positions, and an included angle between two ends of each joint in the plurality of lower limb images in a chronological order to form a series of two-dimensional human rod-shaped model diagrams.

The present disclosure discloses a method and system for constructing a predictive vehicle driving condition, a device and a medium. The method includes: acquiring a first road set and historical vehicle driving data; screening distances less than or equal to a distance threshold from the first distance set, generating a road point-in-time set; sequencing a plurality of point-in-time corresponding to the same road segment, and cutting at two adjacent point-in-time with a time difference greater than a time threshold, to obtain a plurality of road segments; establishing road segment databases; screening segments with segment feature data meeting a second preset condition from all the road segment databases, and generating a road-condition segment set; and sequencing a plurality of condition segments corresponding to each road segment, and screening condition segments meeting a third preset condition from all the segment sequences, to generate an optimal driving condition.

The present disclosure discloses a method and system for constructing a predictive vehicle driving condition, a device and a medium. The method includes: acquiring a first road set and historical vehicle driving data; screening distances less than or equal to a distance threshold from the first distance set, generating a road point-in-time set; sequencing a plurality of point-in-time corresponding to the same road segment, and cutting at two adjacent point-in-time with a time difference greater than a time threshold, to obtain a plurality of road segments; establishing road segment databases; screening segments with segment feature data meeting a second preset condition from all the road segment databases, and generating a road-condition segment set; and sequencing a plurality of condition segments corresponding to each road segment, and screening condition segments meeting a third preset condition from all the segment sequences, to generate an optimal driving condition.

The present disclosure discloses a steady-state site driving condition development method based on a transient-state driving condition, including: fragmenting a laboratory chassis drum transient-state speed-time curve to obtain transient-state motion segments; fragmenting the transient-state motion segment that is not pretreated with reference to a minimum speed of the pretreated transient-state motion segments to obtain transient-state sub-motion segments; merging the transient-state sub-motion segments, calculating maximum constant speeds and mean accelerations and mean decelerations of steady-state motion segments; converting acceleration and deceleration processes into uniform acceleration and uniform deceleration processes, calculating acceleration and deceleration durations of the steady-state motion segments to obtain steady-state motion segment; connecting steady-state motion segments according to time axes, inserting idle segments between the steady-state motion segments and at the beginning and end of a steady-state driving condition, so as to obtain a steady-state site test driving condition.

The present disclosure provides a vehicle auxiliary installation fixing device and a fixing method, wherein the device comprises a frame body, the frame body comprises a pair of side brackets and a pair of end brackets, the pair of side brackets are parallel to each other and both extend along a first direction, the pair of end brackets are arranged along a second direction, the end brackets are arc-shaped and connected with the ends of the same ends of the pair of side brackets, and the second direction is perpendicular to the first direction; the frame body is lined with wave-absorbing material; two groups of fixing components arranged in a first direction. The device can prevent the position of the vehicle under test from moving when the rotating bracket rotates, and avoid the problem of inaccurate test result caused by the scattering of electromagnetic waves by the device itself.

The present disclosure provides a wireless performance testing method and system based on quiet zone expansion in a compact antenna test range. The wireless performance testing method is implemented based on a wireless performance testing device and includes: to acquire an original phase of the feed antenna; rotate the turntable to obtain a first scattering parameter of the device under test; input the first distance to a phase compensation model to obtain a compensation phase; adjust the original phase of the feed antenna to the adjusted phase; rotate the turntable to obtain a second scattering parameter of the device under test; move the feed antenna along the first straight line repeatedly to different positions to obtain a plurality of the second scattering parameters. The wireless performance testing method can increase the size of the test quiet zone under the condition that the reflecting surface size is certain.

An H-type molecular sieve having the CHA framework type is directly prepared through hydrothermal synthesis by using the compounds with the chemical formulas (C 4 H 8 NO) 3 PO and/or (C 4 H 8 NO) 2 PO(C 4 H 10 N) as structure-directing agents. The structure-directing agent has a molecular topological structure, which is conducive to quickly and efficiently building a molecular sieve having the CHA framework type, so that the prepared product has a regular morphology and high relative crystallinity. The synthesis method can directly synthesize the H-type molecular sieve having the CHA framework type with a relative crystallinity greater than 95%. The molecular sieve product can be obtained by direct drying and calcination without an ammonium exchange process, so the synthesis method is simple, easy to perform, and suitable for large-scale production. The samarium-based CHA molecular sieve catalyst shows excellent ammonia adsorption capacity, low-temperature activity, active temperature window, N 2 selectivity, and structural stability in the NH 3 -SCR technology.

The present disclosure provides a design method and device for a high polarization isolation fence which includes the following steps: Setting the material, application environment, and initial structural parameters of the high polarization isolation fence to form an initialized high polarization isolation fence and performing it to obtain antenna performance parameters with the initialized high polarization isolation fence and without the high polarization isolation fence loaded; Debugging the initial structural parameters to determine the optimization range corresponding to each structural parameter; and obtaining the target high polarization isolation fence based on the optimization range corresponding to each structural parameter and the current antenna performance parameters of the initialized high polarization isolation fence. Based on the optimization range, this design method can quickly select the structural parameters of the target high polarization isolation fence with excellent performance, and effectively reduce the design difficulties.

A method for measuring deformation of dummy rib, includes: controlling a plurality of laser device groups to slide along corresponding curve segments respectively, and executing the following steps when the laser device groups slide to each sampling point, to obtain a degree of deformation at a position, corresponding to the sampling point, on to-be-measured dummy rib, the following steps including: controlling a laser range finder to emit a laser beam in a normal vector direction of a tangent corresponding to a position on a slide rail; determining whether the laser range finder receives corresponding reflected laser. This embodiment can have advantages of simple operation, low cost, and high accuracy.