661 results about "Vertical force" patented technology

An example payload for an inspection robot having a mounting rail to inspect an inspection surface, the payload including a wedge element; and a probe holder, including: a mounting rail connection member structured to connect to the mounting rail; a wedge element holder structured to hold the wedge element; a spring-loaded member structured to connect to the mounting rail connection member and to provide a selected vertical force on the wedge element holder; and an extended member structured to connect to the spring-loaded member between a first end and a second end, and to connect to the wedge element holder at the second end.

The invention discloses an elevator operation fault early warning method and system, relates to the technical field of intelligent elevator control, and aims to improve the operation safety and fault response capability of an elevator in a potential abnormal state. By constructing a load critical drift test working condition, a sudden non-vertical stress test working condition and a weak power supply fluctuation interference test working condition, abnormal behaviors which are difficult to appear but have potential safety hazards in the normal operation process of an elevator are induced; the method comprises the following steps: acquiring operation data under various working conditions, respectively calculating a drift overload response coefficient, a guide rail non-vertical interference coefficient and a power supply induced instability coefficient, respectively comparing the coefficients with preset thresholds, and judging whether operation faults such as brake response mismatching, asynchronous action of safety tongs and door lock control interference exist or not; and if the judgment result is abnormal, a targeted strategy is automatically generated and early warning is given out. According to the method, active recognition and classified response of elevator faults can be achieved, and the maintenance efficiency and the operation reliability are effectively improved.

The invention relates to the technical field of machine tool cross beams, in particular to a numerical control gantry machine tool cross beam anti-deformation device which comprises a cross beam, two symmetrically-distributed top connecting pieces are rotationally installed at the top of an inner cavity of the cross beam, and two symmetrically-distributed bottom connecting pieces are rotationally installed at the bottom of the inner cavity of the cross beam. The distance between the two bottom connecting pieces is smaller than that between the two top connecting pieces, tensioning assemblies with adjustable tightness are installed between the bottom connecting pieces and the adjacent top connecting pieces, the two top connecting pieces are located at the two ends of the cross beam, and the two bottom connecting pieces are located in the middle of the cross beam. According to the invention, through the top connecting piece, the bottom connecting piece and the tensioning assembly, an obliquely upward pulling force is applied to the cross beam, the pulling force is decomposed into a vertically upward force and a horizontal force, and the vertical force can offset the gravity of the middle part of the cross beam, so that the downward bending deformation of the cross beam is reduced, and the purpose of reversible deformation is achieved.

The method comprises the following steps: judging whether each wheel clamping force sensor works normally, if so, directly obtaining a brake clamping force as a final brake clamping force, if not, obtaining a first brake clamping force through a motor model, and if not, obtaining a second brake clamping force through a motor model; second brake clamping force is obtained through the brake friction plate model, and fusion is conducted through the fuzzy logic weight algorithm to obtain final brake clamping force; judging whether the wheel has a locking risk or not, if not, calculating the current ground longitudinal force of the wheel according to a kinetic model of the wheel, if so, triggering longitudinal force locking logic, and acquiring the current locking ground longitudinal force as the current ground longitudinal force of the wheel; calculating the current utilization adhesion coefficient of each wheel in combination with the vertical force; and determining the road surface type of the vehicle by using a fuzzy rule based on the adhesion coefficient of each wheel. According to the invention, the problem of low identification precision is solved.

Disclosed in the invention is an off-road vehicle path tracking stability control method for a complex terrain. The method comprises the following steps: step 1, constructing a wheel-ground interaction model to obtain a longitudinal force Fx, a lateral force Fy and a vertical force Fz of the wheel-ground interaction; step 2, by means of the wheel-ground interaction model, constructing a side-tilting evaluation index J1 and a sideslip evaluation index J2, and carrying out weighted processing on the two indexes to obtain a comprehensive stability evaluation index RSS; step 3, training the comprehensive stability evaluation index, and adjusting the weight coefficient of J1 and J2 in the comprehensive stability evaluation index RSS; step 4, by means of the comprehensive stability evaluation index, constructing an MPC controller; step 5, by means of the MPC controller, carrying out stability control on a vehicle. In the invention, a comprehensive lateral stability evaluation index is provided, and the evaluation index is continuously optimized by means of a reinforcement learning algorithm, so that the evaluation index can more accurately represent the lateral stability.

An energy return device for a midsole of a shoe comprises a resilient foam or matrix structure, such as a domed disk, around a cavity. The resilient structure is arranged to collapse into the cavity under foot strike pressure. The structure may initially resist the pressure primarily by compression forces directed around the cavity. As the cavity collapses these forces may provide decreasing vertical spring rate as the structure bends or as the forces become less vertical, causing the structure to stay more compressed through the midstride and energy return to be delayed until the user has moved further forward in their stance. At full collapse the material of the structure may resist further downward force of the user by direct compression. A lateral expansion limiter may resist lateral expansion to increase vertical force supplied by the compression forces around the cavity and reduce interference with other components. A support structure may help guide the collapse and increase spring force.

The invention discloses a method for evaluating the performance of a friction pendulum type seismic mitigation and isolation support in a service state. The method comprises the following steps: S1, carrying out horizontal sliding displacement and vertical force detection on the friction pendulum type seismic mitigation and isolation support in service; s2, according to the detected data, the sliding interface friction coefficient mu of the service friction pendulum type seismic mitigation and isolation support is calculated; s3, according to the obtained sliding interface friction coefficient mu of the in-service friction pendulum type seismic mitigation and isolation support, anti-seismic performance indexes of the friction pendulum type seismic mitigation and isolation support are calculated, and the anti-seismic performance indexes comprise the horizontal rigidity and the effective damping ratio coefficient; and S4, according to the influence of the sliding interface state change and the horizontal rigidity change on the seismic damage state of the bridge structure, the anti-seismic safety risk of the friction pendulum type seismic mitigation and isolation support in the sliding interface state is graded. By means of the method, the sliding interface state and the specific friction characteristic of the friction pendulum type seismic mitigation and isolation support in the service state can be obtained, and therefore the anti-seismic performance of the friction pendulum type seismic mitigation and isolation support can be evaluated.

The invention belongs to the technical field of wind driven generator main bearing test equipment, and discloses a five-degree-of-freedom wind driven generator main bearing test bench for simulating real working conditions, which comprises a loading system, a test system and a driving system. The loading system adopts a sliding bearing loading disc to simulate a hub of the wind driven generator, and adopts a hydraulic cylinder array to simulate five-degree-of-freedom hub loads of three-direction forces including axial force, radial force and vertical force and two-direction moments including pitching moment and yawing moment. The test system adopts a two-point supported tapered roller bearing main shaft system to simulate the main shaft configuration of the wind driven generator, and can be independently disassembled to replace the model of a test bearing. The driving system adopts a variable-frequency and variable-speed motor, the rotating speed range is 0-200 rpm, and the requirements of various working conditions such as frequent start and stop, performance tests and strengthening tests can be met. According to the invention, through multi-dimensional load loading and multi-working-condition simulation, a key platform is provided for reliability test and failure mechanism research of the wind power main bearing.

The invention belongs to the technical field of flight mechanics, and particularly relates to a V-shaped empennage control surface course control extension control method which comprises the steps that a left control surface deflection angle reaches an upper limit, a right control surface deflection angle continues to deflect leftwards, and a right empennage generates right lower lift increment perpendicular to the incoming flow direction; the right empennage can simultaneously generate a vertically downward force and a head-up torque relative to the gravity center of the whole aircraft; a downward head lowering moment is generated through the longitudinal periodic pitch change of the rotor wings and the tilt angle of the rotor wings, so that the pitching moment is balanced; the vertical force balance of the whole aircraft is achieved by adjusting the attack angle of the aircraft body.

The invention relates to the technical field of robots, and discloses a quadruped robot anti-sliding control method, which comprises a sliding detector for estimating the foot end contact condition, and a sliding compensation controller activated after the occurrence of sliding is recognized. The sliding detector judges whether sliding occurs or not by estimating the position and the speed of the contact feet of the quadruped robot in a world coordinate system; realizing a sliding compensation controller of the quadruped robot based on model predictive control, and constructing a model predictive control problem according to a kinetic model of the quadruped robot; and solving the model prediction control problem to obtain the optimal ground control force. According to the method, the speed and displacement errors of the end effector are introduced into the detection model, so that accurate detection of foot end sliding in different gait modes is realized. Meanwhile, the hybrid controller provided by the invention decomposes a control task of stabilizing the sliding leg into horizontal plane position control and vertical force control.

Systems, methods, and other embodiments described herein relate to a vehicle tire guard that retracts in response to a force. In one embodiment, the vehicle tire guard device includes a tire guard extending downward from a vehicle frame and a retraction system attached to the vehicle frame. The retraction system includes a spring-loaded wheel with circumferential interface elements to engage with and retract the tire guard responsive to a vertical force applied to the tire guard, a curved cam affixed to a planar surface of the spring-loaded wheel, and a spring-loaded rod biased against the planar surface. The spring-loaded rod and cam interact to prevent rotation of the spring-loaded wheel to retract the tire guard until the vertical force exceeds a threshold.

The invention discloses a large shield hob layout modeling method and system based on an improved CSM model, and belongs to the technical field of shield tunneling. Selecting corresponding basic parameters based on the project condition and the target cutter; analyzing the generation mechanism of the stress of the target cutter and the mutual relation to obtain the stress characteristics of the target cutter; an improved CSM model is established, and the actual stress of the target tool is obtained through calculation; taking the minimum total radial resultant force of the cutter head and the minimum overturning moment as objective functions, proposing a resultant force constraint condition, an overturning force constraint condition, a stress constraint condition, a mass center position constraint condition and a cutter spacing constraint condition, and constructing a hobbing cutter layout optimization mathematical model; and obtaining a hob layout scheme by using the hob layout optimization mathematical model. According to the method, the improved CSM model is introduced, the vertical force and the rolling force of the hob are considered, and the lateral force is innovatively brought into an analysis framework, so that the comprehensive stress characteristics of the hob in actual tunneling are reflected more accurately.

The invention relates to the field of modular buildings, in particular to a bearing-enclosure integrated wallboard connecting structure which comprises wallboards, force bearing parts and connecting assemblies. The connecting assembly is used for detachably connecting a plurality of force bearing parts; the force bearing piece comprises a horizontal force bearing piece and a vertical force bearing piece; the number of the vertical force-bearing pieces is four, and the vertical force-bearing pieces are arranged in a rectangular shape. The horizontal force bearing parts are arranged between the vertical force bearing parts; the force bearing pieces are connected through the connecting assemblies to form a frame module; when the upper frame module and the lower frame module or the left frame module and the right frame module are connected, the horizontal force bearing pieces or the vertical force bearing pieces arranged side by side are connected through connecting assemblies. The problems that no connection exists between adjacent beams and columns between traditional steel modules, and cooperative work cannot be achieved are solved; the problems that due to the fact that adjacent beams and columns between steel modules cannot work cooperatively, the structural rigidity is low, the anti-seismic performance is poor, the steel consumption is large, and the applicable height of the structure is low are solved.

The invention discloses a suspension pitching cooperative control system and method combining dynamic vertical force distribution and multi-mode braking, and particularly relates to the field of vehicle suspensions. Meanwhile, the braking torque distribution unit and the suspension system are controlled in real time by defining a state machine; vehicle low-speed target braking torque and tire vertical force are calculated through the expected deceleration and correspondingly input into a braking torque distribution unit and a four-degree-of-freedom suspension model; converting the four-degree-of-freedom suspension model into a state-space equation and discretizing the state-space equation to obtain a prediction model, and further deriving a state prediction equation of the future N steps; designing a cost function comprising a state quantity weight matrix Q, an input quantity weight matrix R and a state final value weight matrix F, substituting a prediction state into the cost function to obtain an optimal input sequence, dynamically adjusting suspension rigidity, damping and a braking force distribution strategy, and correcting a control instruction in real time by using closed-loop feedback of a vehicle body attitude sensor, so as to improve the stability of a vehicle body. And the suspension pitching control is realized.

An example payload for an inspection robot having a mounting rail to inspect an inspection surface, the payload including a wedge element; and a probe holder, including: a mounting rail connection member structured to connect to the mounting rail; a wedge element holder structured to hold the wedge element; a spring-loaded member structured to connect to the mounting rail connection member and to provide a selected vertical force on the wedge element holder; and an extended member structured to connect to the spring-loaded member between a first end and a second end, and to connect to the wedge element holder at the second end.

The invention discloses a multi-axial force sensor with force measuring beams with high lateral force sensitivity and strong bending resistance, the multi-axial force sensor comprises a first table body, a second table body and a plurality of force measuring beams, the force measuring beams comprise a transverse force measuring beam and a vertical force measuring beam, the vertical force measuring beam comprises two sheet-shaped vertical beam arms which are parallel to each other, and the two sheet-shaped vertical beam arms are parallel to each other. The orientation of the larger side faces of the two thin-sheet-shaped vertical beam arms is consistent with the extending direction of the two ends of the transverse force measuring beam, and the two vertical beam arms are located on the two sides of the center line of the transverse force measuring beam respectively. The thin vertical beam arms are adopted, when the thin vertical beam arms are subjected to lateral force, deformation of the vertical beam arms is large, high sensitivity of the lateral force can be obtained, meanwhile, the vertical force measuring beam adopts a double-beam form of a thin-wall structure, the two vertical beam arms are separated by a certain distance, and the two vertical beam arms bear bending moment together, so that the force measuring beam can bear large bending moment. That is to say, the force measuring beam can maintain strong bending resistance on the basis of realizing high lateral force sensitivity.

An apparatus for reducing wearer fatigue for use in a wearable safety harness system includes a dorsal chassis capable of engagement with one or more shoulder safety straps and one or more lower torso webbing straps, an attachment subassembly comprising of a D-ring, a self-retracting lifeline attachment point, lower torso webbing strap attachment point, and a force-reduction mechanism. The attachment subassembly is attached to the dorsal chassis via the force-reduction mechanism such that force-reduction mechanism absorbs vertical forces produced by the weight of a self-retracting lifeline. The force-reduction mechanism absorbs vertical forces produced by the lower torso webbing strap resulting from the attachment of tools or equipment to the lower torso webbing strap. The arrangement of the apparatus also promotes increased flexibility between the shoulder safety straps and the lower torso webbing straps torso safety strap, thereby reducing wearer fatigue.

The invention provides valve steel casting strength detection equipment, and relates to the technical field of valve strength detection.The valve steel casting strength detection equipment comprises a transverse sliding rod, a U-shaped vertical supporting frame is welded to the top end of the transverse sliding rod, and a transverse force distribution plate is fixedly arranged below the transverse sliding rod; two L-shaped mounting plates are symmetrically and fixedly connected to the top ends of the square driving block and the vertical force transmission plate, U-shaped mounting frames are fixedly connected to the L-shaped mounting plates, and I-shaped driving parts are slidably mounted on the two U-shaped mounting frames; and two longitudinal limiting shafts are symmetrically and fixedly connected to the bottom end part of the transverse sliding rod, transverse sliding plates are slidably installed on the two longitudinal limiting shafts in a spring pushing mode, positioning insertion shafts are fixedly connected to the inner sides of the transverse sliding plates, and the I-shaped driving part is in penetrating sliding fit with the U-shaped transmission frame. According to the device, the switching and adjusting operation of the use states of the vertical supporting and jacking plate and the jacking swing plate can be driven and executed through one-time sliding of the vertical force transmission plate, the operation steps are simplified, and the operation and use efficiency of the detection equipment can be indirectly improved.

The invention relates to a track top friction regulator roadside coating device and a coating adjusting method thereof, and the track top friction regulator roadside coating device comprises an outer track coating plate, an inner track coating plate, a friction regulator storage module, a transverse force strain gauge, a vertical force strain gauge and a wheel-rail force remote monitoring control system, the friction regulator storage module is connected to the wheel-rail force remote monitoring control system through a storage module signal control line, the transverse force strain gauges are pasted to the top faces of rail feet of the outer rail and the inner rail, and the vertical force strain gauges are pasted to the rail webs of the outer rail and the inner rail. The transverse force strain gauges and the vertical force strain gauges are connected to a wheel-rail force remote monitoring control system through wheel-rail force signal control lines. The method has the beneficial effects that parameters such as the coating amount or the coating frequency of the friction modifier can be dynamically adjusted according to the wheel-rail force, differential coating of the friction modifier of the inner rail and the outer rail can be achieved, the optimal antifriction effect is achieved, meanwhile, the coating amount of the friction modifier is further reduced, and environmental pollution is reduced.

The invention relates to the technical field of elevator assembly performance testing, and particularly provides an elevator component safety automatic detection device. Comprising a detection table, a linkage rack horizontally installed on the detection table in a sliding mode, a vertical test piece assembled on the linkage rack and a horizontal test piece assembled on the linkage rack. The vertical test piece comprises two test assemblies which are vertically and oppositely arranged and a transposition assembly which is assembled between the two test assemblies; the device provided by the invention can be used for detecting the safety strength of the elevator landing door, the elevator landing door to be detected can be fixedly mounted through the arranged detection table, comprehensive detection including a plurality of single tests in two force application directions of vertical force application and horizontal force application can be performed on the elevator landing door, the test comprehensiveness and convenience in operability are improved, and the detection efficiency is improved. And the standardization and uniformity of the test are improved, and the accuracy and reliability of the test result are ensured.

The invention discloses a barrel type foundation structure causeway closure opening sealing structure and a construction method thereof.The barrel type foundation structure causeway closure opening sealing structure comprises a barrel type foundation structure, a plurality of guide frames and a heightening barrel body, the guide frames are installed at the bottom of the heightening barrel body, and the lower portions of the guide frames are of an isosceles trapezoid structure and extend out of the bottom of the heightening barrel body; the lower part of the guide frame is matched with the cavity of the barrel type foundation structure; when the heightening barrel body is installed on the barrel type foundation structure, the guide frame can be clamped into a cavity of the barrel type foundation structure, the heightening barrel body and the barrel type foundation structure are connected into a whole through pouring concrete, the design is reasonable, the structure is compact, it is ensured that the heightening part and the foundation structure are accurately aligned, deviation is avoided, and the construction efficiency is improved. And displacement of the heightening barrel body in the specific direction is limited, shaking caused by water flow force is prevented, the heightening barrel body and the barrel type foundation structure are connected into a whole through concrete pouring, horizontal force and vertical force can be resisted, and the overall stability of the causeway closure opening sealing structure is improved.

The invention relates to the technical field of experimental testing equipment, and discloses a space node multi-dimensional universal loading device which comprises an axial loading and restraining module, a horizontal loading and restraining module and a vertical loading and restraining module. The spatial node multi-dimensional universal loading device is characterized in that the axial loading and restraining module is composed of an axial bottom beam, a restraining check block, a restraining sliding block and axial loading equipment so as to apply axial force and resist torque. According to the invention, axial force, horizontal force and vertical force can be applied to the node test piece at the same time, so that the test of the node test piece under the simultaneous action of multi-dimensional loads is realized; a restraining sliding block and a restraining check block in the axial loading and restraining module are connected with a bottom beam through foundation bolts, and the positions of the sliding block and the check block can be adjusted through tightness of the bolts so as to adapt to node test pieces with different chord member (main pipe) lengths.

The invention discloses a tire three-way force prediction method based on a piezoelectric type intelligent tire technology and a BKA-GPR. A finite element model of a tire and a PVDF (polyvinylidene fluoride) sensor is constructed, and a piezoelectric type intelligent tire model is established in combination with an Inp fusion method; through global sensitivity analysis, sensitivity of changes of a longitudinal force (Fx), a lateral force (Fy) and a vertical force (Fz) to voltage output of the PVDF sensor at different positions in the tire is evaluated, and the optimal installation position of the sensor is determined. A Sobol method is used for collecting a voltage-tire force data set, and extraction and normalization processing are carried out on signals of the ground mark area; the method comprises the following steps of: designing a tire force Gaussian process regression (GPR) model according to data characteristics, and optimizing hyper-parameters of the model through a black-wing kite algorithm (BKA); the optimal input features and the data scale are determined through a random forest (RF) algorithm, and a tire three-way force prediction model which is low in cost, high in precision and good in stability and generalization performance can be obtained by retraining the model.

The invention relates to the technical field of robots, and discloses a jewelry selling robot based on intelligent interaction, which comprises a machine body, and further comprises a frame body fixedly connected to the bottom of the machine body, a driving base fixedly connected to the bottom of the frame body, and a plurality of guide frames which are arranged at equal angles and are horizontally connected to the interior of the frame body in a sliding manner, the multiple pressed parts fixedly connected with the guide frame are arranged, secondary buffering stabilization is conducted through the stability maintaining part, and the stability maintaining part keeps stable continuously when the transmission part does not return to the initial state at the moment. Through the multi-layer structure, accurate coping with collisions with different strengths is achieved, buffer springs directly absorb energy during slight collision, frequent action of a transmission part is avoided, inclined grooves of guide grooves convert horizontal force into vertical force during large collision, all the buffer springs are compressed together, a magnetic ring and an adsorption ring are adsorbed stably, deviation of the robot is avoided, and the service life of the robot is prolonged. And the customer is prevented from being injured when being collided.

The invention provides a coupler force calibration method and device, and the method comprises the steps: obtaining a three-point bending beam model which is used for representing a beam structure formed by the direct connection of a coupling end of a first coupler and a coupling end of a second coupler in a coupling state, and simplifying the tail part of the first coupler into a clamped constraint, the tail of the second car coupler is simplified to be clamped constraint, and the clamped constraint limits the vertical displacement and the rotation angle of the tail of the corresponding car coupler at the same time; applying a vertical load at a preset position on the first car coupler; the bearing reaction force borne by the tail of the target car coupler under the action of the vertical load is determined, so that the calibration relation between the vertical load and the bearing reaction force of the tail of the target car coupler is constructed, and the bearing reaction force of the tail of the target car coupler is the vertical force borne by the tail of the target car coupler and transmitted at the preset position on the first car coupler; the target coupler is one of the first coupler and the second coupler. According to the invention, the accuracy of vertical load transmission calculation is improved.

Systems, methods, and other embodiments described herein relate to a vehicle tire guard that retracts in response to a force. In one embodiment, the vehicle tire guard device includes a tire guard extending downward from a vehicle frame and a retraction system attached to the vehicle frame. The retraction system includes a spring-loaded wheel with circumferential interface elements to engage with and retract the tire guard responsive to a vertical force applied to the tire guard, a curved cam affixed to a planar surface of the spring-loaded wheel, and a spring-loaded rod biased against the planar surface. The spring-loaded rod and cam interact to prevent rotation of the spring-loaded wheel to retract the tire guard until the vertical force exceeds a threshold.

The invention provides a continuous force measurement and calculation method for a spoke type track wheel, and relates to the technical field of wheel-rail force measurement, and the method comprises the steps: uniformly arranging a plurality of strain gauges which are connected to form a bridge circuit on the spoke type track wheel; through a bridge circuit output signal, calculating strain distribution under the action of a unit vertical force, and obtaining an actual vertical force under an external acting force; through superposition and correction of bridge circuit output signals, a transverse force is obtained, and continuous force measurement and calculation of the spoke type track wheel are completed. According to the invention, through carrying out data acquisition on the track wheels and optimizing a resolving algorithm, the force measuring device can rapidly respond to the change of the wheel-rail force, realizes continuous measurement of the wheel-rail force, ensures the real-time performance and the accuracy of test data, and is suitable for various research scenes such as a railway vehicle dynamics test and the like.

An example implementation involves controlling robots with non-constant body pitch and height. The implementation involves obtaining a model of the robot that represents the robot as a first point mass rigidly coupled with a second point mass along a longitudinal axis. The implementation also involves determining a state of a first pair of legs, and determining a height of the first point mass based on the model and the state of the first pair of legs. The implementation further involves determining a first amount of vertical force for at least one leg of the first pair of legs to apply along a vertical axis against a surface while the at least one leg is in contact with the surface. Additionally, the implementation involves causing the at least one leg of the first pair of legs to begin applying the amount of vertical force against the surface.

The invention relates to multifunctional wheel-rail adhesion characteristic testing equipment under simulated extreme working conditions, which comprises a first steel rail pattern, a second steel rail pattern, a first wheel pattern, a second wheel pattern, a low-temperature environment simulation room, a low-pressure environment simulation room, a differential case, a slip adjusting mechanism, a driving mechanism, a vertical force loading mechanism and a torque sensor, the slip adjusting mechanism is connected to the first input end and the second input end of the differential box, the output end of the differential box is sequentially connected to the first steel rail pattern and the second steel rail pattern through a first output shaft, the output end of the driving mechanism is sequentially connected to the first wheel pattern and the second wheel pattern, and the third input end of the differential box is detachably connected to the driving mechanism. The vertical force loading mechanism acts on the first output shaft. The wheel-rail adhesion test device has the beneficial effects that the wheel-rail adhesion test simulation of conventional, closed transmission and braking under low-temperature and low-pressure environments can be realized, so that the requirements of wheel-rail rolling-braking behavior research under long and large ramps and complex extreme climate environments are met.

A control system (300) for controlling an active suspension system (104) of a vehicle (100), the active suspension system comprising suspension actuators (502), the control system comprising one or more controller (301), wherein the control system is configured to: in dependence on an activation signal (904), provide (908) a control signal to the active suspension system to cause the suspension actuators of the active suspension system to repetitively pulse vertical force through wheels (FR, FL, RR, RL) of the vehicle in a controlled pattern determined by the one or more controller, to vary wheel-to-surface contact patch forces, wherein the pattern comprises repetitively pulsing vertical force through at least one of the wheels at a first phase and through at least one other of the wheels at a second phase.