45 results about "Liquid density" patented technology

The application belongs to the technical field of liquid density detection, and discloses a base liquor density detection method for an automatic blending system and related equipment. The method comprises the following steps: acquiring a solvent capacity identifier of current base liquor to be delivered and a residual risk identifier of the last batch of delivered base liquor, judging whether a preset pollution risk time sequence combination exists in a delivery sequence; if the pollution risk time sequence combination exists, delivering the current base liquor to be delivered at a preset flow rate, and collecting a first density measurement value in a first measurement period; then, making the liquid in the delivery pipeline stand still for a preset length of time; then, delivering the current base liquor to be delivered at the preset flow rate again, and collecting a second density measurement value in a second measurement period; calculating a density difference value according to the first density measurement value and the second density measurement value; according to a comparison result of the density difference value and a preset dissolution effect determination threshold, confirming the true intrinsic density of the current base liquor to be delivered; and thus the accuracy and reliability of density detection are improved.

An acoustic wave sensor (1) for waves propagating in a liquid is optically sensitive to variations in the liquid's density caused by pressure changes associated with the passage of an acoustic wave. The sensor is designed to be threaded through a wall (102) of a pipe, for example, in a water distribution network. The sensor is useful for detecting liquid leaks at a distance from its installation location, or for adjusting the intensity of an acoustic wave used to unclog a deposit on a surface in contact with the liquid. (Abstract figure: Figure 2)

The application discloses a kind of water bottom waste liquid self-adaptive collection device and waste liquid collection method, belong to environmental protection technical field.The application includes with the cover opening device and cover closing device of waste liquid recovery barrel cover connection;Utilize the pressure and density variation of water to start cover opening device and cover closing device, realize the automatic opening and closing of waste liquid recovery barrel cover.The application is realized automatic control by spring mechanism and float action in working box.The application utilizes the pressure and waste liquid density variation of water, automatically adjusts spring pressure, to drive gear system to perform cover opening and closing operation, the design of eccentric hole ensures the unidirectionality and stability of gear movement, avoids the possibility of reverse movement or misoperation, enhances the reliability of device in complex underwater environment.

Methods, apparatus, and systems for determining a level of a liquid in a liquid-containing vessel are disclosed. The liquid-containing vessel may be fluidically connected to a displacer cage. The method may include obtaining, with a load measurement device, a weight force of a displacer suspended from the load measurement device and disposed within the displacer cage. The method may also include submerging the displacer into the liquid and obtaining, with the load measurement device, a net force acting on the displacer. The method may further include obtaining, with a liquid density measurement sensor disposed within the displacer cage, a liquid density at a first location of the liquid. The method may still further include determining, using, at least, the net force and the liquid density at the first location of the liquid, the level of the liquid in the vessel.

The invention discloses a chemical liquid density measuring and preparing device and method. The device comprises a measuring assembly and a liquid feeding assembly. The measuring assembly comprises a density measuring container and a weighing sensor, the weighing sensor is configured to be capable of measuring the weight of the density measuring bottle, and a lowest liquid level sensor is arranged on the density measuring container; the liquid feeding assembly comprises a first rotary valve and at least two kinds of chemical liquid, the first rotary valve is connected with the density measuring container through a connecting pipeline, the first rotary valve comprises a first closing valve port and at least two liquid feeding valve ports, and the chemical liquid is connected to the corresponding liquid feeding valve ports through respective pipelines; a liquid flowmeter and a switch valve are arranged on the connecting pipeline, and at least one end, close to the density measuring container, of the connecting pipeline is fixedly arranged, so that the weight measurement of the density measuring container is not influenced by the connecting pipeline. According to the scheme, mixed liquid preparation and density measurement are integrated, high efficiency and convenience are achieved, and potential safety hazards do not exist.

An apparatus and method are provided for optimizing the use of gas hydrate inhibitors by combining real-time "dew point" measurement with quantum-chemical phase-change analysis. A gas hydrate inhibitor reduces gas moisture; by measuring gas humidity and identifying the "dew type" using two chilled-mirror sensors each equipped with an imaging camera, a "dew coefficient" (0–1) is calculated via quantum chemistry analysis of inhibitor solvation. This mesoscale coefficient is used to monitor fluid phase changes. A general relationship for the water / hydrocarbon "dew coefficient" is derived as a function of changes in Gibbs free energy of dew evaporation (inhibitor solvation), gas temperature and pressure, and gas / liquid density. By combining measured "dew point" and "dew type" with quantum chemistry data of phase transformations "dew coefficient", the optimal inhibitor injection rate is determined, minimizing inhibitor consumption while preventing hydrate formation.

The invention discloses a liquid density monitoring method and device, electronic equipment and a storage medium, and relates to the technical field of control, slurry differential pressure signals are collected by means of a preset differential pressure measurement assembly, the density is calculated, and meanwhile measurement, flushing and pollution discharge execution assemblies are connected into an automatic control system to form a closed-loop control process. Sediment accumulation caused by slurry solid content change in long-term operation can be reduced through flushing and pollution discharge, and differential pressure signal fluctuation is avoided; the density value can be dynamically corrected based on historical data and working condition parameters to improve the measurement accuracy, fault self-diagnosis and alarm prompting are achieved by setting fault judgment conditions, manual inspection and experience judgment are replaced, the response speed is increased, and the measurement accuracy is improved. The technical effects of reducing slurry sediments, stabilizing differential pressure signals, reducing the maintenance cost, improving the desulfurization efficiency, avoiding the non-planned shutdown of the system and enhancing the operation stability of the desulfurization absorption tower are achieved.

1. The name of the design product: table type density meter. 2. The use of the design product: for measuring liquid density, alcohol content, sugar content, salinity. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view 1.

The invention provides a float type liquid level monitoring method and device, a medium and a product. According to the method, a control processing unit firstly obtains preset parameters of a floater, initial liquid density and a real-time height value of a height sensor, and a basic data system is constructed for subsequent calculation. And the control processing unit generates a reaction rate curve by using the initial liquid density and the chemical reaction rate equation, and deduces a curve of the mixed liquid density along with the time change through the reaction rate curve, so that the pre-judgment of the dynamic change of the liquid density is realized. Then, the control processing unit calculates the immersion depth in combination with the current density and floater parameters, the liquid level distance is obtained through the distance difference between the height sensor and the bottom of a floater, and finally the actual liquid level is calculated based on the real-time height of the sensor and the liquid level distance. According to the method, the density change is dynamically tracked, errors caused by the immersion depth of the floater are corrected in a targeted mode, the problem of monitoring deviation caused by the density dynamic change is effectively solved, and the accuracy of liquid level monitoring is improved.

The invention discloses an MVR evaporator system which comprises an evaporator, a compressor, a liquid separation unit and a control unit. Wherein the bottom of a liquid separation cylinder of the liquid separation unit is provided with a liquid separation cylinder conveying port, the liquid separation cylinder conveying port is communicated with a bottom discharge port of the evaporator through a first branch, and the first branch is provided with a first bottom valve; the delivery port of the liquid separation cylinder is further connected with a second branch communicated with the outside of the system, and a second bottom valve is arranged on the second branch; the first density sensor is used for measuring the liquid density rho 2b at the bottom of the liquid separation cylinder in real time; the control unit is configured to control the opening and closing states of the first bottom valve and the second bottom valve at least based on rho 2b after liquid in the liquid separation cylinder is subjected to standing layering, so that heavy-component pollutants located on the lower layer and light-component pollutants located on the upper layer after standing layering are discharged to the outside of the system through the second branch, and the heavy-component pollutants located on the lower layer and the light-component pollutants located on the upper layer are discharged to the outside of the system through the third branch. And the liquid in the middle layer is conveyed back to the evaporator through the first branch. According to the evaporator system, the evaporator can still continuously evaporate under the condition of high concentration of wastewater, and the treatment efficiency of the system is greatly improved.

The present application relates to the technical field of ore pulp processing, and particularly relates to a kind of ore pulp and reagent mixing and settling device and working method thereof, device includes mixing reaction mechanism, screen mechanism, settling mechanism and mud outlet mechanism, mixing reaction mechanism includes reaction bucket and vortex guide plate in it, bucket cover and reaction bucket side wall are respectively provided with medicine inlet and feed inlet;Reaction bucket bottom is communicated with settling barrel by spiral discharge pipe;Settling mechanism includes settling barrel and water suction port, and water suction port inlet is arranged in settling barrel, and located above screen;Mud outlet mechanism includes spiral blade, mud outlet and mud pump.The present application is provided with spiral vortex guide plate and staggered side baffle, combined with spiral discharge pipe and discharge baffle, so that ore pulp and reagent complete sufficient mixing, stirring and reaction in conveying process;By setting multiple densitometers, the liquid density at each position in the settling barrel is monitored in real time, so as to automatically adjust according to the actual settling condition, thereby improving the settling efficiency and effect.

The invention discloses a crystal elutriation leg system and a crystal elutriation process. The crystal elutriation leg system comprises an elutriation water distribution section, a crystal mush elutriation discharging section and an elutriation settling separation section which are connected in sequence. And the elutriation water distribution section is provided with a distribution disc with special pore diameter distribution, so that elutriation water is uniformly distributed. The ascending velocity of elutriation water is designed to be larger than the maximum free settling velocity of crystals, so that the distribution disc is prevented from being blocked. In the elutriation settling separation section, the upward flow velocity of clear liquid is controlled to be smaller than the minimum free settling velocity of crystals, so that fine crystals and impurity mother liquor are elutriated, replaced and floated, and target large-particle crystals are settled and enriched in the discharging section. Through cooperative control of the three-section type structure and the key flow velocity, mother liquor impurity entrainment in a crystal product is greatly reduced, the crystal purity and granularity uniformity are improved, and the device is suitable for various crystal separation and purification systems with the solid density larger than the liquid density and has the advantages of being scientific in design, low in cost and high in automation degree.

The invention relates to the technical field of liquid density measurement, in particular to a closed density sensor which comprises a pipe body, a first connecting pipe and a second connecting pipe, the first connecting pipe and the second connecting pipe are fixedly installed on the two sides of the pipe body, and a backpressure adjusting assembly and a second detection assembly are fixedly arranged on the side face of the second connecting pipe. A rectification one-way assembly and a first detection assembly are fixedly arranged on the side face of the first connecting pipe, the second detection assembly and the first detection assembly are the same in structure, the backpressure adjusting assembly comprises a valve body, and a mounting cavity, a matching cavity and a guiding cavity are formed in the valve body. By arranging the back pressure adjusting assembly, the fluid pressure in the whole measuring pipe section is actively maintained to be a set value higher than the liquid saturated vapor pressure and the gas precipitation critical pressure, precipitation of dissolved gas is prevented from the physical source, it is ensured that pure single-phase liquid exists in the measuring cavity all the time, and the measuring accuracy is improved. Therefore, signal fluctuation caused by bubbles is eliminated, and a stable differential pressure signal of real liquid density is reflected.

An apparatus and method are provided for optimizing the use of gas hydrate inhibitors by combining real-time "dew point" measurement with quantum-chemical phase-change analysis. A gas hydrate inhibitor reduces gas moisture; by measuring gas humidity and identifying the "dew type" using two chilled-mirror sensors each equipped with an imaging camera, a "dew coefficient" (0–1) is calculated via quantum chemistry analysis of inhibitor solvation. This mesoscale coefficient is used to monitor fluid phase changes. A general relationship for the water / hydrocarbon "dew coefficient" is derived as a function of changes in Gibbs free energy of dew evaporation (inhibitor solvation), gas temperature and pressure, and gas / liquid density. By combining measured "dew point" and "dew type" with quantum chemistry data of phase transformations "dew coefficient", the optimal inhibitor injection rate is determined, minimizing inhibitor consumption while preventing hydrate formation.

The invention relates to the technical field of desulfurization process control, in particular to a cross-tower coupling stability control system and method for viscose fiber spinning bath desulfurization. Wherein the feed flow, the tower top pressure and the absorption liquid density and temperature are obtained in real time to calculate the absorption liquid saturation degree, the feed flow change rate and the tower top pressure change rate, so that the gas change trend is judged, and the source sink sensing module is awakened in response to the judgment result of the gas sudden increase trend; gas propagation time and concentration load increment are calculated according to the gas concentration at the outlet of the reaction tower and the inlet of the absorption tower so as to determine the gas mass impact state, and a cross-tower cooperative control strategy is formulated based on the gas mass impact state. According to the invention, control islands of the reaction tower and the absorption tower are broken, accurate identification and grading regulation of impact air mass are realized, energy consumption and maintenance cost of instruments are greatly reduced while the absorption tower is not broken down and environmental protection emission continuously reaches the standard, and system safety, economy and operation stability are considered.

The application belongs to the technical field of gas flow measurement, and discloses a hydrogenation machine hydrogenation quantity calibration system, a calibration method and a hydrogenation quantity determination method. According to the scheme, the liquid surfaces in the cavities of the communicating vessel are kept in the same horizontal plane, and the buoyancy principle is used. A floating body is fixed with a gas storage container and placed in the containing cavity of the communicating vessel. The floating body floats in the containing cavity and can freely rise and fall in the containing cavity. The gas storage container is below the liquid surface in the containing cavity, and a liquid level detection unit is arranged in the test cavity communicating with the containing cavity to detect the liquid level height of the test cavity. According to the difference between the liquid level height of the liquid in the test cavity detected by the liquid level detection unit before and after the hydrogenation machine fills hydrogen into the gas storage container, the liquid surface cross-sectional area of the communicating vessel and the liquid density in the communicating vessel, the first hydrogen quantity filled into the gas storage container by the hydrogenation machine is determined, and the hydrogenation machine is calibrated according to the first hydrogen quantity and the hydrogen quantity measured by the hydrogenation machine, so that the accurate calibration of the correction coefficient of the hydrogen quantity measured by the hydrogenation machine is realized.

The invention discloses a method for measuring the evaporation rate of an exposed deck fuel cabin under complex full working conditions, which comprises the following steps: when the fuel cabin is in a full working condition state, respectively collecting the state data of the fuel cabin at the beginning of measurement and at the end of measurement through a sensor; according to the state data of the fuel cabin, an LNG liquid phase density value, a gasification latent heat value and an LNG steam specific heat value are calculated through an empirical formula; according to the fuel cabin state data and the LNG liquid phase density value, the evaporation gas flow is calculated; the evaporation rate is calculated and measured according to the fuel cabin state data, the evaporation gas flow and the LNG liquid phase density value; according to the boil-off gas flow, the gasification latent heat value and the LNG steam specific heat value, calculating through an energy conservation rule to obtain standard boil-off gas flow; and the measured evaporation rate is subjected to standardized correction through the standard evaporation gas flow and the LNG standard state data, and the standard evaporation rate of the full-working-condition fuel cabin is obtained. According to the method, the evaporation rate of the exposed deck fuel cabin can be accurately measured under complex full working conditions.

The utility model discloses a testboard, and relates to the field of flowmeter testboards. The test board comprises a water storage tank, a measuring cylinder unit, a transfer water tank, an electric appliance control cabinet, a control unit, a water pump and an electric fitting drain valve unit. According to the test board, the measuring cylinder water inlet pipeline adopts a shared pipeline for water inlet and adopts a same outlet for discharging air, so that the same pressure and liquid density in each measuring cylinder are ensured, and the increase of large and small flow reference errors caused by pressure and volume changes is avoided; the closing time of the double-valve electromagnetic valve is quantitatively controlled through the electric appliance control cabinet, after the volume reaches 95% of the designated volume, the large valve is automatically closed through the double-valve electromagnetic valve, small-flow water supply reaches 100% of the designated volume, and the situation that when large-flow water supply is carried out, due to the fact that the flow speed is high and the speed is high, the flow rate is large is avoided; instant cut-off easily causes damage to a pipeline valve.

The application discloses a device for monitoring the performance of a fracturing fluid, and the device is used for monitoring the performance of the fracturing fluid. The device comprises a proportional mixing module, a density measuring module, a viscosity measuring module, a resistance reduction rate measuring module and a control and communication module. The control and communication module specifically performs the following method: obtaining the liquid density of a liquid storage tank and the sand density of a sand mixing truck tank, and calculating the sand concentration of a target fracturing fluid sample based on the density, mass and volume of the target fracturing fluid sample, the liquid density and the sand density; obtaining the initial pressure difference of the resistance reduction rate measuring module before measurement, and calculating the resistance reduction rate of the target fracturing fluid sample according to the inlet pressure, the outlet pressure and the initial pressure difference; and monitoring the performance of the fracturing fluid in real time based on the viscosity, the resistance reduction rate, the sand concentration and the density.

1. The name of the design product: liquid density concentration meter. 2. The use of the design product: for density concentration detection. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.

The utility model relates to the technical field of evaporator related facilities, and one embodiment of the utility model provides an MVR horizontal gas-liquid separator which comprises a separation tank, supporting legs are arranged at the bottom of the separation tank, a driving separation assembly is arranged in the separation tank, and a filtering and discharging assembly is arranged at the inner bottom of the separation tank; a fan blade is arranged on the side wall of the stabilizing sleeve, a blowing blade is connected to the side wall of the driving main shaft, and a feeding port and a discharging port are formed in the side wall of the separating tank. According to the technical scheme, the problems that a traditional gravity type gas-liquid separator in the related technology / the prior art mainly depends on the gas-liquid density difference to achieve separation, the separation efficiency of the mode is low, the ideal separation effect is difficult to achieve under the conditions that the gas-liquid density difference is small or gas-liquid mixing is complex, and the separation efficiency is poor are solved. Although a centrifugal gas-liquid separator improves the separation efficiency to a certain extent, the centrifugal gas-liquid separator is relatively complex in structure and high in energy consumption, and the problems of abrasion and the like are easily caused in the long-term operation process.

The utility model relates to a magnetic float liquid level transmitter relates to liquid level transmitter technical field. Liquid level balance pipe left end sealed welding flange A, flange A and blind plate A are sealed through gasket and bolt sealed connection, liquid level balance pipe left side sealed welding liquid inlet pipe, liquid inlet pipe is welded on liquid level balance pipe upside, liquid inlet pipe extends to left side after horizontal arrangement, and gas balance pipe is established to liquid inlet pipe upside. The utility model has the advantages of: the upper portion of the measuring tube is in communication with the container to be measured through the gas balance pipe, the air pressure on both sides is the same, and the liquid level on both sides is in a horizontal state. The liquid in the liquid level balance pipe is separated by the balance piston, and the height of the magnetic float ball in the measuring tube is independent of the liquid density of the measured liquid level, thereby avoiding the problem of inaccurate measurement results caused by the different densities of the liquid.

The invention discloses a multi-parameter cooperative control method and device for double-prediction-mechanism dense medium coal separation. The method comprises the steps that multiple pieces of to-be-input data associated with the dense medium coal separation system at the current moment are obtained; inputting the plurality of to-be-input data into a pre-trained model prediction control mechanism model, and determining first prediction suspension density at a plurality of first moments in the future; and inputting a plurality of pieces of data to be input into a pre-trained long-short term memory network, and outputting second predicted suspension density at a plurality of second moments in the future, determining a target predicted suspension density at a third moment in the future through the two predicted suspension densities obtained through prediction; and adjusting at least one control parameter associated with the dense medium coal separation equipment based on the target predicted suspension density, wherein the control parameters comprise one or more of the opening degree of a water replenishing valve, the state of an underflow discharge valve, the frequency of a frequency converter, the opening degree of a pressure valve and the running state of a circulating pump. And the accuracy of multi-parameter cooperative control is improved.

An automatic liquid density measuring instrument comprises a plunger pump, a high-pressure air pump, a six-way valve, a cylindrical tube, a transparent glass tube, a constant-temperature water bath box, a peristaltic pump, an infrared transmitting tube, an infrared receiving tube, an optocoupler box and a cap. The problems that when the density of the viscous liquid is manually measured, a measuring cylinder is not easy to clean after measurement, and an automatic U-shaped oscillation tube method cannot be used for measuring the density of the viscous liquid are solved, the density of the viscous liquid can be conveniently and rapidly measured, and the measurement accuracy is improved. And the automatic density measuring instrument can be used for cleaning the measuring device without residues after the measurement is finished. The method is particularly suitable for popularization and application in the fields of petroleum, medicine and industrial production, and the market prospect is very wide.

The method according to the invention is used to determine a mixture density measurement value ρm of a gas-laden liquid by means of a Coriolis mass flowmeter having a measuring tube for guiding the gas-laden liquid. The method comprises: ascertaining (210) an initial mixture density value on the basis of at least one natural frequency of a bending vibration mode of the measuring tube; ascertaining (220) a mass flow measurement value; ascertaining (230) an initial gas volume fraction value αs on the basis of the initial mixture density value ρs and a liquid density value ρi; ascertaining (240) a final gas volume fraction value αf on the basis of the initial gas volume fraction value αs and the mass flow measurement value; and (250) ascertaining the mixture density measurement value on the basis of the liquid density value and the final gas volume fraction value αf.

The application discloses a steam condensation experimental device for accurately measuring instantaneous flow of condensed water and belongs to the technical field of condensation heat transfer experimental measurement. The steam condensation experimental device for accurately measuring instantaneous flow of condensed water can solve the problem that most of the existing experimental devices cannot measure the flow of condensed water in real time, and comprises a condensed water collecting system, wherein the condensed water collecting system is connected with a steam-water separation system, the condensed water collecting system comprises a condensate tank for collecting condensed water, a liquid level detection mechanism for measuring the change of the liquid level in the condensate tank in real time and a temperature detection mechanism for detecting the temperature of the condensed liquid in real time are arranged in the condensate tank, and the liquid level detection mechanism is connected with a data acquisition system. The mass flow of the condensed liquid flowing into the condensate tank can be calculated in real time through the liquid level height and the liquid density of the condensed liquid, and the size of the condensation heat transfer amount and the condensation heat transfer coefficient of the experimental section at different moments can be obtained.

The invention belongs to the technical field of mineral liquid level measurement, and particularly relates to a mineral liquid level measurement method and system based on piezoresistive liquid level sensors, and the method comprises the steps: obtaining two liquid pressures measured by the two piezoresistive liquid level sensors with the fixed height difference in real time; according to the difference of the two liquid pressures, the mine liquid density is calculated by combining a first formula; according to the mine liquid density, the mine liquid level height is calculated by combining a second formula. Real-time acquisition of the liquid density is achieved by synchronously monitoring the pressure of the ore liquid at different heights, data is provided for correction of the liquid level height, and the problem that liquid level measurement is inaccurate due to the fact that the liquid density in a mine is unknown or changes along with time is solved.

The object of the present invention is to provide a method for producing a PHA having a low water content. The object is attained by providing a method for producing a PHA, including a filtration step of filtering an aqueous PHA suspension having a pH of 2.5 to 5.5, by filter-pressing with use of a filter medium having an air permeability of 0.1 cm3 / cm2 / min to 2.5 cm3 / cm2 / min, the aqueous PHA suspension having a liquid density of 0.50 g / mL to 1.08 g / mL in the filtration step, the filtration step including a compression step and an air blow step.

A device for dispensing a fluid product comprises a metering valve mounted on a reservoir (1) containing at least one active ingredient suspended in a pressurized propulsion gas, the pressurized propulsion gas having a liquid density of less than or equal to 1.20 g / cm3 at 21 DEG C, the metering valve comprises a valve body (10) containing a metering chamber (20) and a valve closing member (30) axially sliding in the valve body (10) between a reset position and a dispensing position for dispensing the contents of the metering chamber (20), the metering chamber (20) being substantially isolated from the reservoir (1) when the valve closing member (30) is in the reset position, the valve body (10) comprises at least one fluid passage opening (11), the metering valve defines a settling volume V arranged below the at least one passage opening (11) in an inverted use position in which the metering chamber (20) is arranged below the reservoir (1), the settling volume V being greater than or equal to 500 mm3 and less than or equal to 1000 mm3.

The invention discloses a transportation liquid profit and loss acquisition method, device and equipment and a storage medium. When the method provided by the embodiment of the invention is executed, the calculation of the final mass of the target liquid is realized by firstly acquiring the primary quantity and the first liquid identifier of each target liquid and acquiring the state parameters of each transport vehicle at the destination by using the state parameter measuring equipment. And then, determining a transport vehicle according to the matching of the first liquid identifier and the second liquid identifier, and calculating the profit and loss amount of each target liquid according to the primary amount corresponding to the first liquid identifier and the final mass of the matched vehicle, thereby ensuring the mutual corresponding relationship between the mass of the target liquid and the vehicle. Besides, parameters such as liquid density, temperature and liquid level are obtained by using state parameter measuring equipment, so that real-time monitoring of the liquid state is realized, a data foundation is laid for accurate calculation of profit and loss, and meanwhile, the conditions of data errors and disordered summarization are effectively avoided through a clear mass-vehicle corresponding relation.