118 results about "Chassis dynamometer" patented technology

The invention provides a method for testing the cooling performance of a vehicle retarder, and the method comprises the steps: placing a vehicle on a chassis dynamometer in an environment cabin, and adjusting the temperature parameter and humidity parameter of the environment cabin to simulate an outdoor environment; setting a gear of a retarder of the vehicle as a constant speed gear, adjusting a gradient parameter of a chassis dynamometer to a first preset gradient so as to simulate a driving gradient of the vehicle, and controlling the vehicle to run at a first preset vehicle speed; in the process that the vehicle runs at the first preset vehicle speed, the vehicle speed, the vehicle running time, the vehicle running mileage and the inlet and outlet temperature difference of retarder cooling liquid are recorded; an analysis result is generated according to the speed of the vehicle, the driving time of the vehicle, the driving mileage of the vehicle and the inlet and outlet temperature difference of the retarder, and the analysis result is used for representing whether the cooling performance of the retarder meets the design index or not. The environment working condition and the road working condition are adjusted according to test requirements, test variables are accurately controlled, and the test result is prevented from being influenced by the external environment and the road working condition.

A steering model controller in a chassis dynamometer of the disclosure executes a turning determination process of determining whether a driving state of a vehicle is a steering / turning state or a driving straight state based on comparison results between a turning radius for determination and turning radii for comparison calculated based on left steering angle information and right steering angle information. Then, the steering model controller executes a turning control process as a roller control process to be executed in determining that the vehicle is in the steering / turning state. The turning control process is a process of outputting, to a roller driving mechanism, four roller driving commands at which four rollers adapt to the steering / turning state of the vehicle and are rotationally driven.

The invention relates to a vehicle speed control method and device for a vehicle hub rotating experiment, electronic equipment and a vehicle, and relates to the technical field of vehicles, and the method comprises the steps: obtaining a vehicle dynamic model of a tested vehicle; the vehicle dynamic model is used for reflecting the corresponding relation between the motion parameters of the tested vehicle and the state parameters of the power control pedal; under the condition that the tested vehicle placed on the rotating hub test bench is started, according to the rotating hub vehicle speed of the tested vehicle at the current moment and the target vehicle speed that the tested vehicle wants to reach at the next moment, state parameters of a power control pedal of the tested vehicle are determined; and controlling the rotating hub speed of the tested vehicle based on the state parameters of the power control pedal. Therefore, the state parameters of the pedal are controlled through unrated power, the rotating hub speed of the tested vehicle can be more accurately controlled, and the accuracy of vehicle speed control is improved.

The invention relates to the technical field of automobile testing, in particular to a method for testing long braking attenuation of an automobile by using an environmental wind tunnel. Comprising the following steps: installing a chassis dynamometer in an environment wind tunnel, and installing data acquisition equipment on a tested vehicle; setting a tested vehicle in the environment wind tunnel, setting environment parameters in the environment wind tunnel as target working condition parameters, and setting a chassis dynamometer as downhill working condition parameters; after the environment state and the dynamometer are stable, the vehicle is controlled to run continuously within the speed precision range required by the speed spectrum through continuous braking, or when the vehicle is controlled to run continuously to a set emergency deceleration point, emergency braking operation is executed, and experimental data are collected synchronously until a preset test ending condition is met; and after filtering and noise reduction, abnormal value elimination and altitude-slope conversion processing are carried out on the acquired experimental data, the performance attenuation law and the emergency efficiency of the braking system are analyzed. According to the technical scheme, the test precision of the long-braking attenuation of the automobile can be improved, and the test cost is reduced.

The invention provides a pure electric drive wheel fixing device of a new energy automobile chassis dynamometer, and relates to the technical field of new energy automobiles, the pure electric drive wheel fixing device comprises a mounting seat, a self-adaptive driving mechanism, a clamping and fixing mechanism, a sliding seat, a sliding groove and a supporting seat; the wheel fixing device has the advantages of being reasonable and simple in structure, low in production cost and convenient to install, through cooperative action of the telescopic mechanism and the clamping mechanism, lifting of the connecting base and moving of the clamping block can be achieved, wheel fixing can be completed without complex manual operation, the operation process is greatly simplified, the labor cost is reduced, and meanwhile equipment installation and later maintenance are facilitated; by means of cooperation of a driving assembly in the self-adaptive driving mechanism, a sliding base and a sliding groove, the clamping and fixing mechanism can be driven to flexibly adjust the transverse position, the fixing requirements of non-driving wheels of new energy automobiles with different axle distances can be met, frequent replacement of accessories or manual calibration is not needed, the adaptation capacity of diversified automobile types is effectively improved, and the practicability is high. And the large-scale detection operation requirements are met.

The present application relates to the technical field of vehicle performance detection, and particularly relates to a coasting time detection system and method. The system comprises: establishing a data link between a main control unit and a speed sampling device, automatically identifying the speed sampling device and completing communication initialization configuration; adjusting the sampling roller to make it abut against the surface of the chassis dynamometer roller and locking the spatial pose through a multi-stage adjusting mechanism; setting a starting speed threshold and an ending speed threshold based on the measured speed interval and configuring a conversion reference; controlling the main control unit to enter a monitoring state, receiving an original pulse signal based on a preset clock frequency and converting it into a real-time linear speed, automatically triggering timing and latching the effective coasting time according to the real-time linear speed; and associating and storing the effective coasting time with test attribute information. The present application realizes self-adaptive and accurate positioning of the sampling roller through the multi-stage adjusting mechanism, and automatically triggers timing based on a one-way continuous downward trend, thereby improving the precision and efficiency of the coasting time detection.

The utility model belongs to the technical field of whole vehicle data acquisition, and particularly relates to a variable inertia chassis dynamometer, which comprises a bottom rod and a baffle plate, the baffle plate is fixedly connected to the upper side of the bottom rod, the left end and the right end of the lower side of the bottom rod are fixedly connected with universal wheels, and the upper end of the bottom rod is connected with an acquisition mechanism. When the chassis dynamometer with the variable inertia is used, a rotating handle is rotated to drive a threaded rod to rotate in a threaded hole, so that the threaded rod moves relative to a bottom rod and drives a supporting plate at the lower end to move to make contact with the ground, the whole device is supported and fixed, and then an output shaft of a motor is started to rotate to drive a gear at the right end to rotate; the gear rotates along the upper end of the toothed bar and moves at the same time, so that the motor and the moving rod at the lower end of the motor are driven to move together, and the infrared distance measuring sensor at the upper end of the moving rod passes through the lower portion of the automobile chassis to detect the distance between each automobile part in the chassis and the ground.

The objective of the present invention is to provide a chassis dynamometer that suppresses resonance and vibration phenomena, without changing the mechanical structure of the chassis dynamometer. An inverter (4) of a chassis dynamometer (1) according to the present disclosure includes: a notch filter (40) that attenuates a signal in an attenuation target frequency band including the mechanical natural frequency of the chassis dynamometer 1, from a rotation command signal (S3), and outputs a rotation command signal (S3A); a secondary HPF (45) that passes signals in a high-frequency band including the mechanical natural frequency, among an encode signal (S7), to obtain an encode signal (S7A); a subtractor (47B) that subtracts the encode signal (S7A) from the rotation command signal (S3A) to obtain a rotation command signal (S3B); and a roller drive control unit (RC) that generates a drive control signal (S4) on the basis of the rotation command signal (S3B).

The present invention relates to the field of passenger vehicle energy-saving technology, and discloses a system and method for evaluating the energy-saving effect of a hybrid vehicle intelligent energy management strategy. The system comprises a map navigation simulation module, a non-intelligent hub fuel consumption test module, an intelligent hub fuel consumption test module, an oil-to-electricity energy conversion and wheel-side energy normalization module, and an energy-saving effect evaluation module. The present invention activates / deactivates the intelligent energy management strategy of a test vehicle by simulating navigation map information, and uses a chassis dynamometer for testing, eliminating the influence of factors such as the road environment, traffic conditions, and weather conditions to obtain the energy-saving effect of the intelligent energy management strategy. This method has the characteristics of high accuracy, short test cycle, and strong practicality, and can also reversely support the calibration and optimization of the intelligent energy management strategy.

To provide a fuel efficiency evaluation system applicable to vehicle testing that uses camera images to acquire illuminance and solar radiation amount.SOLUTION: A fuel efficiency evaluation system which evaluates the fuel efficiency of a vehicle comprises: a transition unit which transitions the vehicle state to a test mode in which a fuel efficiency evaluation test is performed using a chassis dynamo device; a derivation unit which derives a test solar radiation amount corresponding to the air conditioning settings of an air conditioner in the test mode; a control unit which controls the air conditioning of the air conditioner based on the test solar radiation amount; and a fuel efficiency evaluation unit which evaluates the vehicle's fuel efficiency in a state where the air conditioning of the air conditioner is controlled.SELECTED DRAWING: Figure 1

On a premise that a longitudinal direction of an automobile is defined as an x-axis direction and a width direction of the automobile is defined as a y-axis direction, a supporting mechanism S includes a tilting support 2 which is disposed below a load motor M and tiltably supports the load motor M in an axis line direction of a rotational axis M1 of the load motor M with respect to a top-down direction, a rotary support 3 which is disposed below the load motor M and rotatably supports the load motor M in an x-y plane, a mounting frame 4 connected to the load motor M through the tilting support 2, a movable table 1 which is positioned just below the mounting frame 4 and connected to the mounting frame 4 through the rotary support 3, and a sliding portion 5 which is disposed just below each of end portions in the x-axis direction of the movable table 1 and is capable of causing the movable table 1 to slide in both the x-axis direction and the y-axis direction.

The invention relates to a tire steering detection device for a chassis dynamometer, a synchronous steering correction mechanism and application thereof, and belongs to the technical field of automobile chassis testing. On one hand, the tire steering detection device is arranged to detect the steering data of the wheels in real time, and after the tire steering detection device communicates with the second driving assembly, the second driving assembly controls and corrects the rotation condition of the rotary drum according to the steering data, so that the rotation condition is synchronous and consistent with the steering of the wheels; the testing and correcting mode is high in measurement accuracy and fast in response and correction, and the defect that a traditional dynamometer cannot rotate along with the tire can be thoroughly overcome. And on the other hand, the speed and the drum surface force of the rotary drum can be controlled and calculated through the first driving assembly, so that various driving scenes of the automobile tire arranged on the rotary hub are simulated and adapted, and the adaptability is wide.

The invention relates to a chassis dynamometer shafting system with a shielding function for testing a whole three-axle heavy vehicle, and belongs to the technical field of chassis dynamometers. According to the chassis dynamometer shafting system, the two sections of rails are arranged on the underframe, and the three shaft assemblies are matched on the rails to form the chassis dynamometer shafting system suitable for testing the whole three-shaft heavy vehicle, so that the problem that an existing dynamometer cannot meet the requirements of the three-shaft heavy commercial vehicle and the variable wheelbase is solved. The system comprises three test shafts corresponding to six hubs of a three-shaft vehicle. According to the design, independent road load simulation is provided for each wheel, and it is ensured that all axles, especially third axles, can be tested under the real road load. Besides, the second axle and the third axle are provided with an adjustable axle distance mechanism, relative movement can be achieved through a push rod assembly, the axle distance adjusting range covers 1300-1600 mm, and the axle distance requirement of an existing three-axle heavy truck on the market is met.

To restrain tires pivotably without giving breakage and damage to a vehicle body or tires of a test vehicle and the like.SOLUTION: One end parts 6a of a plate 6 are arranged in front of and behind a front wheel tire 1a of a test vehicle 1 loaded in a roller device 19 of a chassis dynamometer system 2. In the one end part 6a of the plate 6, an arcuate-like free roller 8 group is arrayed so as to clamp the front wheel tire 1a. Each of the free rollers 8 is pivoted pivotably to a bracket 7 on the one end part 6a.SELECTED DRAWING: Figure 5

The invention relates to the technical field of vehicle testing, in particular to a whole vehicle braking wear particulate matter testing system under laboratory conditions. The system comprises a chassis dynamometer, a vehicle head fan, a tested vehicle, a connection system, a collection system, a test system and a verification system. The chassis dynamometer is used for providing various resistances in the normal driving process of the automobile; the automobile head fan provides cooling airflow in the automobile driving process; in the running process of the tested vehicle, braking wear particles are generated by a braking system; the connecting system connects the tested vehicle with the collecting system; the collecting system is used for capturing brake wear particles generated by the brake assembly; the test system is used for acquiring emission characteristics of brake wear particles of the tested vehicle; and the verification system is used for obtaining the test efficiency of the brake wear particles in the test scheme and correcting a final result.

The invention provides a whole vehicle braking comfort evaluation method for simulating a user use scene working condition. The whole vehicle braking comfort evaluation method comprises the following steps: establishing an acquisition vehicle database; establishing a climate database; establishing a user use scene working condition comprehensive database; establishing a whole vehicle braking comfort subjective evaluation system; and comprehensive evaluation of the whole vehicle braking comfort level is realized. The method has the beneficial effects that the two-dimensional envelope matrix climate database is established based on the typical characteristic city of the climate gradient zone in China, and the comprehensive database under the user use scene working condition is established by using the vehicle driving road working condition in China; a whole vehicle silencing environment cabin and a whole vehicle brake chassis dynamometer are combined to quickly and efficiently reproduce the working condition of a user use scene, and meanwhile, whole vehicle brake comfort level judgment work with low development cost, high development efficiency and short development period is carried out through a whole vehicle brake comfort subjective evaluation method; and the driving comfort quality of the whole vehicle is further effectively improved.

The invention provides a pure electric drive new energy automobile chassis dynamometer, which relates to the technical field of new energy automobiles, and comprises a fixed seat, a dynamometer device I, a placement walking device, a dynamometer device II and an adjustable mechanism, the device has the advantages of being reasonable and simple in structure, low in production cost, convenient to install and complete in function, the distance between the two power measuring devices can be adjusted through the displacement mechanism, the test requirements of new energy automobiles with different axle distances can be met, meanwhile, the stability of the power measuring devices in the moving process can be ensured through cooperation of the sliding bases and the supporting strip bodies, and the test efficiency is improved. The influence of position offset after adjustment on the test precision is avoided; the auxiliary walking device is arranged, the motor drives the transmission structure to drive the auxiliary walking plate to move transversely, temporary walking support can be provided for the vehicle, the vehicle can smoothly run to the designated position of the dynamometer conveniently, external hoisting equipment does not need to be additionally used, the vehicle loading operation process is simplified, and the test preparation efficiency is improved.

A chassis dynamometer for motorcycles with a combustion engine, having a mounting unit, at least one fastening unit, an operating unit, a control unit and a roller for recording the peripheral speed of a motorcycle rear wheel is disclosed. The chassis dynamometer has a flow unit a drive unit, a diffuser and an outflow unit arranged downstream of the diffuser in the direction of flow where the diffuser and outflow unit form a flow channel carrying gas in the operating state, wherein the diffuser can be driven by the drive unit, where the control unit controls the drive unit as a function of the peripheral speed of the roller in such a way that a speed of the gas emerging from the outflow unit in the operating state is substantially equal to the peripheral speed at least from a peripheral speed of 150 km / h.

1. Name of the designed product: road simulation machine for chassis of automobile (XS series). 2. Use of the designed product: for simulating and detecting abnormal sound of chassis vibration during automobile driving. 3. Design points of the designed product: in shape. 4. Picture or photo best showing the design points: perspective view.

The invention relates to an auxiliary tool for a chassis dynamometer. The chassis dynamometer auxiliary tool comprises a base; the connecting part comprises a rotating part and a supporting part, the rotating part is rotatably arranged on the supporting part, the rotating part is used for being detachably connected with a transmission shaft of a vehicle, the transmission shaft is used for being connected with a tire, and the transmission shaft can drive the rotating part to rotate relative to the supporting part when rotating; and the height adjusting mechanism is arranged on the base, the supporting piece is connected with the height adjusting mechanism, and the height adjusting mechanism is used for adjusting the height of the connecting part. According to the scheme provided by the invention, the multi-axle vehicle can be tested on a mainstream two-axle chassis dynamometer.

The invention discloses a second-hand automobile market price assessment method, and relates to the technical field of price assessment, and the method comprises the following steps: through a chassis dynamometer, an engine comprehensive detector, an oil consumption detector and a brake detection bench, detecting and obtaining the engine power, the oil consumption per hundred kilometers and the brake distance of a current to-be-assessed second-hand automobile; the method comprises the following steps: collecting reference parameter data of a current to-be-evaluated second-hand automobile, including automobile age and mileage, establishing a second-hand automobile database through MySQL, establishing a file by combining the collected data of the current to-be-evaluated second-hand automobile with engine power, fuel consumption per hundred kilometers and braking distance, and summarizing the file into the second-hand automobile database. According to the method, the evaluation value of the second-hand automobile is reasonably adjusted through basic automobile condition evaluation and regional value compensation and by comprehensively considering the market requirements of the brand and color of the current second-hand automobile and the influence of regional characteristics, so that the final second-hand automobile identification price is more accurate and fair.

The utility model belongs to the technical field of dynamometers, and provides a four-wheel drive chassis dynamometer, which comprises a dynamometer frame assembly, four mounting grooves distributed in an array are arranged on the dynamometer frame assembly, and a unit dynamometer is correspondingly mounted in each mounting groove; the unit dynamometer comprises a unit dynamometer main body and a weight regulator; the weight adjuster comprises a limiting piece and a weight adjusting base, and the limiting piece is assembled on the weight adjusting base; the weight adjusting base comprises an air cylinder, the air cylinder is fixed to the limiting piece, the pressure between one automobile wheel and the unit dynamometer body is correspondingly adjusted through telescopic adjustment of the air cylinder, and adjustment of the pressure between one or more automobile wheels and the unit dynamometer body is completed. The situation that the gravity center of the vehicle-mounted heavy object is not always at the parallel point and one or more automobile wheels may exist is accurately dealt with, and the test reasonability and precision are improved.

The present application relates to a kind of automobile automatic driving function dynamic verification system and method, including millimeter wave radar target simulator, wave-absorbing box, chassis dynamometer system, virtual scene simulation system, test management and automatic test module, linear motor and rack, the front of wave-absorbing box is provided with the open box mouth, the front of box mouth is directly opposite the front radar of the car, the back of wave-absorbing box is installed with the radio frequency head antenna of millimeter wave radar target simulator, and the inner wall of wave-absorbing box is provided with wave-absorbing cotton layer.The ADAS function test of automatic driving vehicle is changed from the actual road of outdoor test field to indoor laboratory environment, and the problems such as limited outdoor test site, higher test risk and inability to test without automatic driving test license are solved.The present application has the advantages of low test cost, good repeatability, reliable test verification system environment, saving vehicle road test time and cost.

A hub directly driven by a motor and used for a heavy-duty chassis dynamometer includes a hub body, wherein a mounting surface is arranged on an inner circumference of the hub body and is disposed around a transmission shaft coaxial with the hub body, the transmission shaft is sleeved with a driving assembly, and bearing assemblies are disposed on two sides of the driving assembly in an axial direction respectively; a plurality of axial mounting plates are disposed on an outer circumference of the driving assembly, and tension sensor assemblies are connected to the axial mounting plates located outside the hub body and are mounted on the support frame; and an end, away from the mounting surface, of the transmission shaft, is sleeved with an end flange plate, and a plurality of brake assemblies are disposed on the end flange plate and are mounted on the support frame.

The utility model relates to the technical field of automobile detection, in particular to a new energy chassis dynamometer working face safety detection device which comprises a bottom plate, a fixed plate and a sliding plate are arranged on the bottom plate, the fixed plate is fixedly connected with the bottom plate, and the sliding plate is in sliding fit with the bottom plate in the length direction of an automobile. The bottom plate is further provided with a first driving mechanism used for driving the sliding plate to act. A front vehicle-feeding vehicle-guiding plate is arranged on the bottom plate and located above the fixed plate, a rear vehicle-discharging vehicle-guiding plate is arranged on the sliding plate, the front vehicle-feeding vehicle-guiding plate and the rear vehicle-discharging vehicle-guiding plate are located on the same horizontal plane, and supporting rods are arranged on the opposite side faces between the front vehicle-feeding vehicle-guiding plate and the rear vehicle-discharging vehicle-guiding plate in a crossed mode; telescopic stand columns are arranged at the two corners of the front side of the front bicycle guiding plate and the two corners of the rear side of the rear bicycle guiding plate correspondingly, and correlation switches are arranged on the opposite side faces of the adjacent telescopic stand columns. Through the correlation switches arranged at different heights, an electronic fence function is formed, and an alarm can be given out in time for the mistaken entering situation in the detection process.

The utility model discloses a chassis dynamometer centering mechanism, and relates to the technical field of chassis dynamometers. The device comprises a measuring plate table, the right side of the measuring plate table is provided with a slope block, the right side of the slope block is provided with a rotating roller, the right side of the rotating roller is provided with a protection box, the left side of the measuring plate table is fixedly connected with a first motor, the top of the measuring plate table is provided with a moving groove, and the output end of the right side of the first motor is fixedly connected with a threaded rod. The right side of the threaded rod is rotationally connected with the right side of the inner wall of the moving groove. According to the utility model, the first moving plate, particularly the two electric push rods, is arranged, and the two electric push rods are started at the same time; a sliding barrel, a sliding rod and a second connecting lug which are located on the back face synchronously slide on the surface of a first rail, so that two clamping plates on the front face and the back face clamp a front wheel of a motorcycle, the motorcycle is fixed, and a stable environment is provided for detection so that detection data can be accurate.

This disclosure aims to provide a chassis dynamometer that generates a steering wheel restoring force when the vehicle is in a steering turn state to perform a vehicle driving test. The turning model controller (21) in the chassis dynamometer (1) of this disclosure performs a turning determination process and a turning command angle calculation process based on left turning information (S1L) and right steering angle information (S1R). The turning determination process is a process that determines whether the vehicle (60) is in a steering turn state or a straight-ahead state. The turning command angle calculation process is a process that calculates the left turning command angle (θlv) and the right turning command angle (θrv) for controlling the roller turning mechanism (DM1) when the vehicle is in a steering turn state. The left turning command angle (θlv) is smaller than the left steering angle (θl) indicated by the left steering angle information (S1L), and the right turning command angle (θrv) is smaller than the right steering angle (θr) indicated by the right steering angle information (S1R).

The application discloses an adjustable easy-centering transmission chassis dynamometer device and a dynamometer method, which comprise a base, a dynamometer hub, a sinking space, a sliding groove, an axial translation support and front and rear adjusting supports; a pair of the front and rear adjusting supports in the front and rear directions are provided with an adjusting interval on the dynamometer hub; a plurality of liftable support seats are further arranged on the middle part of the base; auxiliary positioning brackets are respectively arranged on the outer sides of the axial translation supports; the auxiliary positioning brackets are arranged in positive correspondence with the central axis of the dynamometer hub; and a centering sensor is arranged on the auxiliary positioning bracket. The adjustable easy-centering transmission chassis dynamometer device is convenient for the centering adjustment between a pair of wheels of a heavy-load vehicle, has high centering accuracy and high flexibility.

The invention discloses a wind tunnel test method for dynamic waterproof sealing performance of a passenger vehicle. The method comprises the following steps: checking and servicing a target vehicle to be tested; setting a chassis dynamometer and an automobile environment wind tunnel; putting the target vehicle into a chassis dynamometer, and starting to heat the vehicle; after the vehicle heating is completed, the target vehicles are tested in sequence according to the set test working conditions; and after each test working condition is completed, performing waterproof inspection recording on a power assembly system, a chassis component, a high-voltage electrical component, a low-voltage electrical component, a vehicle body component and an air conditioning system of the target vehicle, and then entering the next test working condition until all the test working conditions are completed. The dynamic environment of wind and rain coupling in the driving process of the vehicle is simulated through the vehicle environment wind tunnel, the waterproof sealing performance of the passenger vehicle is comprehensively tested, and the problem that the test comprehensiveness of the waterproof sealing performance is insufficient in the prior art is solved. The invention is mainly used in the technical field of vehicles.

The application discloses a heavy vehicle carbon emission and oil consumption partition reconstruction evaluation method suitable for remote monitoring and actual road test, which is characterized in that: remote monitoring data or actual road test data of a target vehicle model are taken as vehicle real-time data input, vehicle real-time data per second and engine speed and net output torque of the drum data are partitioned and data correlated, average oil consumption level of the target vehicle model is obtained through data clustering of the partitioned data, reconstruction data of carbon emission or oil consumption level of each partition is obtained based on drum data prediction and average oil consumption level of the target vehicle model, different partition reconstruction data are spliced according to engine cycle process of the target vehicle model during oil consumption authentication on a chassis dynamometer, carbon emission or oil consumption level of the target vehicle model during use is obtained, and conformity or compliance of the carbon emission or oil consumption level is compared with an authentication result. The application improves the use efficiency of remote monitoring and actual road test data, and is simple in calculation, high in accuracy and strong in adaptability.