2559 results about "Tractive force" patented technology

To provide a braking control device of a vehicle that can execute starting-assist control of suppressing a vehicle from moving backward on an uphill road, which can improve hill-climbing performance.SOLUTION: A braking control device comprises an actuator that can individually adjust braking torque applied to a plurality of wheels, and a controller that holds the braking torque so as to prevent a vehicle from moving backward on an uphill road through the actuator and then executes starting-assist control of gradually reducing the braking torque. The controller can execute traction control by which the braking torque is increased in a slip wheel in which an acceleration slip of the wheel becomes larger than a predetermined slip to reduce the acceleration slip. Further, the controller determines a final control amount Qt on the basis of a first control amount Qa of the braking torque relating to the starting-assist control and a second control amount Qb of the braking torque relating to the traction control, and controls the braking torque on the basis of the final control amount Qt.SELECTED DRAWING: Figure 5

The invention relates to the technical field of ship control, in particular to a fishing boat control system based on data analysis, which comprises a traction load analysis module, a fluctuation condition division module, an attitude disturbance estimation module, a propulsion power regulation module and a rudder angle correction output module. According to the method, by analyzing the traction force load sequence value and the moment arm length of the fishing net traction point, calculating the left and right side offset torque and marking the action direction, the attitude adjustment precision of the ship is optimized, the operation sea condition level is adjusted according to data, and the ship can be subjected to more reasonable attitude estimation and adjustment under the dynamic working condition; the wind pressure change rate and the pitch angle rate are combined to judge the direction resultant force trend, and the navigation attitude is adjusted according to the sea condition grade, so that the ship can more accurately resist the influence of sea surface storm waves and maintain the course stability, and the rudder angle is corrected by adjusting the propulsion power in real time, limiting the adjustment amplitude of the propulsion power and correcting the rudder angle according to the real-time data of the navigation attitude. And the propulsive efficiency and the navigation precision are optimized.

The invention relates to the technical field of electric vehicle control, and discloses a stability control method and system for an electric vehicle, and the method comprises the steps: collecting vehicle driving data in real time, and dynamically estimating the state parameters of the vehicle through an unscented Kalman filtering algorithm; according to the state parameters of the vehicle, combined with the kinematic model and the foresight trajectory, the expected yawing moment in a short time in the future is calculated, and the longitudinal traction requirement of the vehicle is obtained; and according to the state parameters of the vehicle and the longitudinal traction requirement of the vehicle, the yawing moment and the traction force are decoupled and distributed to the four electric driving wheel ends, and stable control over the electric vehicle is achieved. Compared with a traditional stable control system only based on closed-loop feedback, the stable control system has the advantages that the control response is faster, the yawing intervention is more accurate, and better control performance and vehicle safety are shown under the low-adhesion road surface and high-load working conditions.

Footpad assemblies of the present disclosure include a footpad configured to be coupled to a frame of an electric vehicle and a foot engagement structure coupled to the footpad. The foot engagement structure is configured to contact the rider's foot to prevent undesired movement of the rider's foot during use of the electric vehicle. The footpad includes a recess defined in an upper surface of the footpad and an insert is disposed in the recess and coupled to the footpad. The insert is operatively coupled to the foot engagement structure. The foot engagement structure may comprise a foot stop extending above the footpad and configured to abut a side portion of the rider's foot and / or a traction insert configured to contact a bottom of the user's foot to provide grip or traction. The position and rotational orientation of the foot stop relative to the footpad is configured to be adjustable by a user.

The invention provides a train ATO (automatic train operation) energy-saving method, device and equipment, a medium and a program product, and belongs to the technical field of rail transit. Constructing a constraint function in the train operation process; and under the condition of the constraint function, solving the optimal solution of the target function by adopting a dynamic programming algorithm to obtain the lowest traction energy consumption. According to the train ATO energy-saving method provided by the invention, the target function taking the lowest traction energy consumption as the target is constructed, the constraint function is formed by combining the specific constraint conditions in the train operation, and the dynamic programming algorithm is used for solving the target function, so that the optimal solution under the constraint conditions can be accurately found, and the lowest traction energy consumption can be obtained; the traction energy consumption is reduced by optimizing the operation curve in the ATO operation process, the energy efficiency of train operation is improved, and the operation cost of urban rail transit can be greatly reduced.

The invention relates to the field of locomotive power battery electric quantity control, and particularly discloses a locomotive power battery electric quantity hysteresis equalization control method, which comprises the following steps that: a traction force exerting mode is reset into an axle load transfer mode, and the initial value of an electric quantity equalization compensation coefficient K is a rack axle load transfer coefficient corresponding to zero speed; judging whether the current mode is a power battery power supply mode; if yes, the TCU receives the electric quantity of a front power battery and the electric quantity of a rear power battery in real time according to the current locomotive working mode, calculates the electric quantity average value difference value, monitors the auxiliary load power and the traction motor power and calculates the power difference value; entering a hysteresis control logic process; calculating a dynamic traction force compensation coefficient, ensuring that the traction force compensation amount is matched with the actual load characteristic of the system, correcting the traction characteristic curve in real time, and dynamically compensating the electric quantity difference of the battery; and performing traction distribution control according to the locomotive speed and outputting corresponding traction.

Slip target adjustment based on an accelerator pedal is provided. A system can detect an amount of torque requested for a vehicle. The system can determine a friction level associated with a surface on which the vehicle traverses. The system can select a slip target modifier. The selection can be based on the amount of torque requested for the vehicle and the friction level. The system can adjust a slip target used by a traction control system of the vehicle. The adjustment can be based on the slip target modifier.

Tire traction is dynamically increased in a vehicle by performing a sequence of steps. The vehicle includes a controllable suspension having a damper, a spring, and an active element, a suspension controller, and a controllable aerodynamic element. The body of the vehicle is positioned at a level which allows for a predetermined amount of upward suspension travel. The suspension controller receives a trigger after the body of the vehicle is positioned at a level which allows for a predetermined amount of upward suspension travel. The suspension controller generates a first control signal upon receipt of the trigger. The first control signal is sent to the active element to generate the positive impulse. The positive impulse causes application of force to the wheel of the vehicle in a downward direction, thereby dynamically increasing tire traction. Oscillation of the body of the vehicle is inhibited using the damper as the body of the vehicle oscillates as a result of the spring, thereby inhibiting oscillation of tire traction. The rise of the body of the vehicle is limited by modulating the variable downforce on the body of the vehicle generated by the controllable aerodynamic element.

The invention relates to the technical field of conveying belts, in particular to a cutting-resistant rubber conveying belt which comprises two side plates, two roller shafts are rotationally connected between the two side plates, belt rollers are fixed to the outer sides of the two roller shafts, and the outer sides of the two belt rollers are in transmission connection with a rubber conveying belt body. Two traction mechanisms are symmetrically arranged between the two ends of the two roll shafts and the two side plates, and a plurality of buffer supporting mechanisms are further arranged between the two roll shafts. The multiple clamping mechanisms are driven by the traction mechanism to synchronously move along with the rubber conveying belt, and in the moving process, each clamping mechanism can apply certain traction force to multiple point positions of the side edge of the rubber conveying belt, so that the traction force acting on the rubber conveying belt is distributed more uniformly, and the conveying efficiency is improved. The rubber conveying belt is prevented from being broken or cracks are formed in the side edges due to the fact that traction force of the two belt rollers is excessively concentrated at the two ends of the rubber conveying belt, and the service life of the rubber conveying belt can be effectively prolonged.

The invention relates to the technical field of automatic driving, in particular to a driving control method and system for an unmanned electric tractor, and the method comprises the following steps: obtaining humidity data to generate a state diagram, judging slip to trigger traction adjustment based on the state diagram, analyzing a slope recognition risk to generate a slope parameter, and reading a braking force to judge, coordinate and generate a distribution instruction. According to the method, the humidity difference is obtained through multi-point soil humidity monitoring, distribution characteristics are extracted, accurate sensing of the state of an operation area is achieved, the wheel rotating speed and traction force signals are combined, slipping is recognized in advance, the traction force is dynamically adjusted, and the driving force is kept stable; based on joint analysis of gradient change and vehicle state, slope risk is recognized in advance, optimization control is performed, braking force of front and rear wheels is dynamically distributed, slippage caused by unbalance is avoided, safety of complex terrains is improved, and vehicle stability, path control precision and energy utilization efficiency are improved through cooperation of multi-dimensional data perception and dynamic prediction.

The invention discloses a wide crawler walking device suitable for seabed thin and soft geology, which realizes stable walking of a deep-sea heavy-load mining operation platform on a thin and soft substrate through a high-tooth large-width composite material crawler walking mechanism, and provides a power driving guarantee for later operation of a heavy and heavy collection device. The crawler walking module is used for providing enough traction force for the mining vehicle, so that the mining vehicle can normally run on the complex bottom surface of the seabed. A crawler walking device is located in a chassis, the overall width of a vehicle body is reduced, a main beam of the chassis penetrates through trolley frames on the two sides, chassis secondary beams are welded to outer side panels of the trolley frames, the bearing capacity of the chassis is improved, the trolley frames are of a simple frame structure, and through holes and open grooves are machined in left and right outer side plates of the trolley frames and used for installing driving wheels, guide wheels and bearing wheels. Welding or bolt connection of other wheel train installation type structural parts is omitted, the lightweight design is met, and the structural strength is enhanced.

The invention relates to the technical field of mechanical arms, and discloses a high-degree-of-freedom mechanical arm which comprises a supporting arm mechanism and a grabbing mechanism, the grabbing mechanism comprises a telescopic assembly and two clamping jaw assemblies, the telescopic assembly is connected with the supporting arm mechanism, and the two clamping jaw assemblies are symmetrically arranged on the two sides of the telescopic assembly; the telescopic assembly is used for driving the two clamping jaw assemblies to conduct clamping action. By means of the grabbing mechanism, when the pipeline is installed in an inserted mode, the middle position of the pipeline can be grabbed and transferred firstly, so that the stability of the pipeline transferred to the preset installation position is guaranteed, and after the pipeline is transferred to the preset position, the pipeline is fixed. And the grabbing width of the grabbing mechanism, the pipeline contact structure and the mode of generating traction force on the pipeline are actively changed through the grabbing mechanism, the manual pushing effect is matched, the pipeline is stably pushed to the preset installation position, the operation of manually using a rope to assist traction is omitted, and the pipeline installation difficulty is reduced.

The invention belongs to the technical field of mechanical transmission, and discloses a conductor ring and magnetic resistance array composite permanent magnet thrust bearing and a damping force calculation method. The conductor ring and magnetic resistance array combined type permanent magnet thrust bearing realizes the bearing of non-contact magnetic thrust through the combination of the eddy current ring and the magnetic group array. When thrust from a propeller at the stern end of a propulsion shafting acts, the rotor magnetic group array axially moves, axial traction force is generated between the rotor magnetic group array and the stator magnetic resistance array to counteract the thrust action from the axial direction, meanwhile, the magnetic group array cuts the vortex ring, induction damping is generated on the surface of the vortex ring, damping force is formed, and the vortex ring is driven to rotate. And therefore, the longitudinal vibration during transmission of the propulsion shafting is reduced, and the propulsion shafting system is more silent and stable during operation. In addition, the damping force calculation method does not need complex three-dimensional structure modeling and grid division, is simple in solution, high in universality and short in calculation time consumption, and has high engineering application practical value.

An electrified vehicle includes a human-machine interface to enable a towed vehicle mode to enable electric pumps to lubricate and / or cool vehicle components and to disable driver assistance features while the electrified vehicle is being towed by another vehicle. The electrified vehicle includes a drivetrain having an electric machine configured to provide propulsive torque to vehicle wheels, a high-voltage traction battery selectively connected to the electric machine, a battery powered fluid pump configured to pump fluid to the drivetrain, and a controller programmed to, after receiving a signal enabling towed vehicle operation of the electrified vehicle, control operation of the battery powered fluid pump while the electrified vehicle is being towed. The controller may disable one or more driver assistance features and alerts such as automatic emergency braking, automatic shifting of the drivetrain, automatic parking brake operation, automatic headlights, automatic steering, cruise control, parking assistance, and external object distance detection.

The present invention relates to the field of crane equipment, and in particular to a sway reduction and stabilization device for a crane hoist. In view of the problem in the prior art that a steel wire rope will inevitably shake during the speed regulation of a trolley, a sway reduction and stabilization device for a crane hoist is provided. Two first auxiliary ropes that are cross-arranged with each other are respectively arranged on the front and rear sides between a stabilization plate and a mounting plate. The lower ends of the first auxiliary ropes are respectively fixedly connected to fixed plates. When the crane trolley drives the hoist to move, the fixed plates are pulled mutually by the first auxiliary ropes that are cross-arranged with each other. Under the action of a two-way ratchet self-locking structure, while ensuring that the first auxiliary rope can be retracted and released by a first winding wheel, the pulling force from the first auxiliary rope cannot drive the first winding wheel to rotate, so that the first auxiliary rope can effectively maintain traction, reduce the shaking of the hoist during movement, and enhance the stability of the hoist during movement.

The invention relates to a four-motor traction control method, device and equipment and a readable storage medium, and belongs to the field of control over vehicle transmission systems.The method comprises the steps that the target wheel speed of each wheel is calculated by obtaining the actual vehicle speed of a target vehicle at the current moment and the actual wheel speed and the wheel acceleration of each wheel; calculating the wheel speed change rate correction amount of each wheel based on the wheel acceleration of each wheel at the current moment and a plurality of historical wheel accelerations of each wheel at a set historical moment; determining the slippage control adjustment amount of each wheel and judging whether slippage occurs or not; if the wheels slip, target motor torque of the wheels is calculated based on the wheel speed change rate correction amount of the wheels and a preset motor torque calculation rule, and traction force of the wheels is controlled based on the target motor torque. According to the method, the effects of improving the traction force control precision and stability of the vehicle under different road conditions, reducing the slipping phenomenon and improving the driving safety and comfort are achieved.

The invention relates to the technical field of traction wheels, in particular to an antiskid traction device for a steel wire rope on an elevator traction wheel. An anti-skid traction device for a steel wire rope on an elevator traction wheel comprises a fixing frame and further comprises a traction large wheel rotationally connected to the fixing frame, a transmission module is arranged on the fixing frame, the traction large wheel is driven through the transmission module, an inner bevel gear ring is in transmission connection with the transmission module, and a set of steel wire ropes are arranged on the outer side of the traction large wheel. And the group of traction modules are distributed in a circumferential array and are mounted in the traction bull wheel. The synchronous multi-point multi-power traction structure for the steel wire rope through the traction large wheel and the traction small wheel has the beneficial effects that on one hand, the traction force borne by the steel wire rope can be effectively improved, and on the other hand, the friction contact area and the friction strength of the steel wire rope and the traction large wheel and the traction small wheel can be effectively improved; the anti-skid effect of the steel wire rope is effectively improved.

The invention relates to an electric traction machine (10) for a motor vehicle, comprising a stator (16), a rotor (18) which can be rotated relative to the stator (16) about an axis of rotation (22), a hollow rotor shaft (20) on which the rotor (18) sits for conjoint rotation and within which oil (28) can be conducted, and a housing (12) surrounding the stator (16) and the rotor (18), wherein: the rotor shaft (20) is supported on the housing (12) by means of at least one rotor shaft bearing (24); for lubrication of the rotor shaft bearing (24), an outlet opening (42) associated with the rotor shaft bearing (24) is provided in the rotor shaft (20), through which outlet opening oil (28) can exit the rotor shaft (20); a deflection element (44) is provided, by means of which the oil (28) that has exited the rotor shaft (20) can be deflected to the rotor shaft bearing (24).

The invention belongs to the field of rail traffic control, and provides a heavy-load group train wheel-rail adhesion cooperative control method which comprises the following steps: respectively establishing a heavy-load double-compiled group train dynamic model, a rail surface recognition model, a wheel-rail adhesion control model and a group operation control model; inputting the equivalent braking force or traction force of the wheel and the normal force of the wheel rail into the rail surface recognition model, calculating an estimated value of an adhesion coefficient, and inputting the estimated value into the group operation control model; and inputting the estimated value of the adhesion coefficient, the speed, time and wheel pair angular velocity of the pilot train and the speed, time and wheel pair angular velocity of the following train into a wheel-rail adhesion control model, calculating motor torque of the pilot train and the following train and an output logic decision value of the following train, inputting the motor torque and the output logic decision value into a group operation control model, and performing adjustment control to obtain the wheel-rail adhesion coefficient. The motor torques of the pilot train and the following train after adjustment and control are obtained; and inputting the adjusted and controlled motor torques of the pilot train and the following train into the heavy-load double-compiled group train dynamical model.

The present invention discloses a support mechanism of a self-adaptive traction robot for a complex wellbore and a control method thereof, and relates to the technical field of oil and gas field development. Each support link assembly in a support mechanism is controlled by an independent hydraulic cylinder and hydraulic valve. When a well wall that each support link assembly contacts in a circumferential direction is irregular, the support mechanism contact effect is not ideal, which leads to a decrease in traction force. In this case, a displacement sensor in a telescopic mechanism detects that a displacement of a traction cylinder piston is small, which is fed back to a ground control system, and then a fluid inflow size of support cylinders corresponding to different support link assemblies is adjusted until the displacement sensor in the telescopic mechanism detects an effective traction distance.

The invention discloses a material fatigue crack propagation prediction method based on a cyclic cohesion model of a random vibration load. The method comprises the following steps: building a crack propagation analysis finite element model based on the cyclic cohesion model; based on the established crack propagation analysis finite element model, calculating the strain of the whole non-cohesion region unit and the separation displacement of the cohesion unit under the current time increment step; according to the separation displacement and the frequency and the amplitude of the current vibration load, the traction force increment in the current time increment step is calculated, and the cohesion strength, the critical separation displacement and the accumulated separation displacement in the traction separation criterion after the fatigue damage increment is loaded are updated; and unit failure judgment is carried out according to the fatigue damage, and if the fatigue damage is reduced to 0 and the cohesive unit rigidity value is reduced to 0, it is judged that macroscopic expansion of fatigue cracks occurs. According to the method, reasonable prediction of fatigue crack growth under the random vibration condition is realized, and the method has wide adaptability.

The invention relates to the technical field of heavy-load trains, in particular to a simulation system, method, equipment, medium and product for a long marshalling heavy-load train, and the system comprises a traction simulation subsystem which is used for inputting train operation data into a preset traction characteristic curve to obtain a train traction force; the braking simulation subsystem is used for inputting the train operation data into a pre-constructed braking establishment process simulation model to obtain a train braking force; the longitudinal simulation subsystem is used for inputting the marshalling conditions into a pre-constructed buffer simulation model to obtain train coupler force; the decision optimization subsystem is used for obtaining a control command of the train based on the train operation data, the marshalling condition, the train traction force, the train braking force, the train coupler force and an optimization strategy; and the operation of the long and large marshalling heavy haul train can be simulated.

A gear system is provided for a wheel of a tractor. The gear system includes a plurality of planet gears and a plurality of rollers. The planet gears are operable to rotate to provide tractive force to the wheel. The rollers are operable to abut against an inner ring of the wheel to reduce a contact force from the wheel contacting a channel on the plurality of planet gears.

The utility model provides an automatic turning plate device of a car roof tent. The automatic turning plate device comprises a first bottom frame, a top frame, a first shear fork type lifting frame, a turning plate, a driving device, a pull rope and a torsional spring. The side portion of the first bottom frame is rotationally connected with a turning plate, a first shear fork type lifting frame is arranged between the first bottom frame and the top frame, the upper end of a first fork and the lower end of a second fork in the first shear fork type lifting frame are sliding ends located on the same side, and the two sliding ends are arranged on the top frame and the first bottom frame in a sliding mode respectively. The driving device is connected to at least one fork so as to drive the two forks to rotate, open and close around the crossed hinged position; a torsional spring is arranged between the turning plate and the first bottom frame, one end of the pull rope is connected with the sliding end, and the other end of the pull rope is connected with the turning plate. Through the cooperation of the traction force of the pull rope and the torsion force of the torsion spring, when the tent is lifted to be unfolded and folded, the turning plate is linked to be automatically unfolded and folded, the use is convenient, time and labor are saved, and the structure is simple and stable.

The invention relates to the technical field of textile machinery processing, and discloses a bearing inner ring grinding device and method suitable for textile machinery, the bearing inner ring grinding device comprises a mounting bottom plate, a supporting seat is fixedly connected to one side of the top end of the mounting bottom plate, a rotating cylinder is mounted on the outer side of the supporting seat, and a plurality of inserting holes are formed in the inner side of the rotating cylinder; a moving block is slidably connected to the inner wall of the rotating cylinder, a threaded rod is in threaded connection to a through hole in the outer side of the moving block, a driving plate is in threaded connection to the outer side of the threaded rod, and a rotating rod is rotationally connected to the outer side of the driving plate. A movable block is moved upwards or downwards to drive a hinge rod to swing, and a grinding disc is driven to move outwards under the action of traction force of the hinge rod until the grinding disc can be in close contact with the inner wall of the bearing inner ring, so that the polishing effect on the bearing inner ring is improved, and the polishing precision is improved; and meanwhile, inner rings of bearings of different specifications can be polished, and the use flexibility of the device is greatly improved.

The invention provides a driving structure of a crawler belt of a stretcher crawler, and belongs to the technical field of the stretcher crawler, the driving structure of the crawler belt of the stretcher crawler is provided with a dual-driving system, and a crawler belt assembly surrounds two driving wheels and a supporting wheel to form a complete transmission path. Crawler tension changes can be detected in real time, and the rotating speed of the second driving motor can be automatically adjusted. When the front-section resistance of the track is increased, the tension detection device senses the change, and the mechanical speed regulator reduces the rotating speed of the second driving wheel through the centrifugal block and the transmission gear set to form a rotating speed difference to increase the front-section tension of the track so as to provide larger traction force. The whole system follows the constraint relation that delta n = n1-n2 = k * delta T + C, it is ensured that the rotating speed difference linearly corresponds to the tension change, and accurate dynamic adjustment of the crawler tension is achieved through coordinated operation of the double driving wheels.

The invention provides a laying construction system and method for a long-distance large-diameter cable in a cable trench. The laying construction system for the long-distance large-diameter cable in the cable trench comprises a traction device which is used for providing stable and adjustable pulling force in the cable laying process and ensuring that the cable stably moves along a preset path, and a guide device which is arranged at a key position in the cable laying path and prevents the cable from being twisted, deformed or damaged in the moving process. According to the laying construction system and construction method for the long-distance large-diameter cable in the cable trench, the problem is successfully solved by introducing a multi-segment traction device and a tension control system, and a segment traction unit in the traction device can independently adjust traction force according to actual conditions of different path segments; and the traction force of each section is ensured to be uniformly distributed through a real-time feedback system, so that the cable is prevented from bearing non-uniform tension in the moving process.

There is disclosed a device for use with a continuous track of a tracked vehicle. The device has a first component and a second component. Each component has an elongate body having first and second slots at one end, a third slot at the other end, ground engaging features, and a U-shaped bracket. The device has a first configuration in which a first fastener extends through the first slot of the first component and the third slot of the second component and a second fastener extends through the first slot of the second component and the third slot of the first component. The device has a second configuration in which the first fastener extends through the second slot of the first component and the third slot of the second component and the second fastener extends through the second slot of the second component and the third slot of the first component.

The invention discloses a casting device and method for producing a high-quality valve casting, relates to the technical field of metal casting devices, and solves the problems that when the cast casting is demoulded, the casting is cooled, and the traction force between the casting and a material in a lower mould base is relatively large, so that the casting is not easy to deform. The lifting rod can be moved out from the interior of the lower die base only through large extrusion force, and damage to a driving source and a casting is large. The casting device for producing the high-quality valve casting comprises a device support and a casting box, an upper support is installed at the top of the device support through screws, the casting box is arranged in the center of the top of the upper support, and the casting device comprises a vibration demolding mechanism installed in the upper support; and the casting mold is arranged in the casting box. According to the demolding device, through forward and reverse rotation of the driving source, the castings under different conditions can be ejected and demolded, the demolding effect is improved while the demolding efficiency is improved, and the quality of the demolded valve castings is guaranteed.

The invention relates to the technical field of vehicle control, and discloses a method and system for adjusting control parameters of a traction control system and related equipment.The method comprises the steps that current road condition information of a vehicle is obtained, and the current working condition corresponding to the vehicle is determined; all driving data of the vehicle from beginning to end under the current working condition are obtained, and the corresponding traction force control condition of the vehicle under the current working condition is determined; driving behavior parameters of a driver are obtained, and the weight of each control parameter of the traction force control system is determined; according to the current working condition, the traction force control condition and the weight, control parameters of a traction force control system are adjusted, and target control parameters are determined. The driving environment and the driving habit are considered when the control parameters of the traction control system are adjusted, so that the adjustment of the traction control system on the control parameters is more in line with the current use scene, and the efficiency of calibration matching work of the traction control system is improved.