RU2388865C1 - Portable device to measure coefficient of wheel-to-road coating adhesion - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: proposed device comprises first and second torque transducers, electromagnetic brake, angular velocity transducer, time pickup with display and storage unit. First mechanical output of the wheel is connected to first torque transducer with its first and second outputs connected to first and second inputs of registration unit, respectively. Second mechanical output of measuring wheel if connected via second torque transducer with electromagnetic brake rotor. Power supply is connected via controlled power supply with electromagnetic brake. Angular velocity pickup, time pickup and second torque transducer are connected to third, fourth and fifth inputs of registration unit with its second and third outputs connected to display and storage unit. Sixth free input of registration unit makes the input of dynamometre of roller-type brake stand. First torque transducer measures moment of force (Mg) of measuring wheel adhesion to artificial coating surface, while second torque transducer measures moment of force (M) of measuring wheel braking. Device hardware is arranged on the frame that rests on measuring wheel to act on artificial coating as normal load force P. Adhesion coefficient is determined when M-Mg=ΔM and calculated from the formula Kadh=F/P; F=Mg/r; Kadh max=Kadh×k; k=Mg*/Mg where Kadh, is adhesion factor; Kadh max is maximum adhesion factor; F is adhesion of measuring wheel with artifical coat surface, N; P is normal load of measuring wheel on artificial coat surface, N; Mg is moment of adhesion force of measuring wheel, Nm; M is moment of braking generated by electromagnetic brake, Nm; ΔM is increment of the moment of force that ensures start of measuring wheel slippage, Nm; r is measuring wheel radius, m k is slippage factor calculated in device calibration; Mg* is maximum moment of wheel-to-coat adhesion force, Nm.

EFFECT: higher accuracy of measurements.

1 cl, 1 dwg

Description

The invention relates to a device for determining the coefficient of adhesion of the wheel on the constructed and operated roads, as well as at airfields and can be used in the investigation of traffic accidents.

Known portable meter coefficient of adhesion IKSp, which is used in the construction, repair and routine monitoring of the condition of road surfaces. The device contains: a vertical bar, a shoe simulator of a car tire and cargo

The principle of operation of the device is based on determining the magnitude of the horizontal movement on the wetted surface of the shoe - a car tire simulator. The car tire simulator is pressed against the road surface at an angle of 45 degrees. The kinetic energy of a load freely falling along a vertical bar is used as a source for moving a shoe - a simulator. The horizontal movement of the shoe pressed against the moistened road surface - the simulator - depends on the coefficient of adhesion, in the proportions of which the reading scale of the device is graduated.

The disadvantages of the known portable device include: low accuracy of the measurements, measurements are carried out only in the summer period of time and low productivity in the work when measuring the coefficient of adhesion.

Another well-known measure of the coefficient of adhesion of road surfaces is the portable device PPK-MADI-VNIIBD (TU 78.1.004-87, state register number 10912-87). The device contains:

car tire simulators, push rods, clutch, guide rod, humidifier, load, reference scale and measuring washer.

The device is installed on the road surface so that tire simulators rise 10-12 mm above the surface of the road surface. Then the road surface under the simulators is moistened. Dump the load, which slides along the guide rod and hits the clutch. Through the push rods and hinges, the shock pulse is transmitted to tire simulators that interact with the road surface. The adhesion coefficient is determined on a reference scale using a measuring washer.

However, this device also has a number of significant disadvantages:

- a large limit of permissible basic reduced measurement error;

- insufficient limits for measuring the coefficient of adhesion (0.05-0.65);

- significant duration of one measurement cycle;

- measurements are taken only in the summer.

Closest to the claimed invention in technical essence is a "Device for measuring the coefficient of adhesion of the wheel with the road surface" having the maximum number of similar significant features with the features of the claimed device and therefore adopted as a prototype (patent of the Russian Federation RU 2244057 C1, 7 Е01С 23/07) .

The known device is a prototype (figure 1) contains: a measuring wheel 1, an auxiliary wheel 2, a frame 3, bearing bearings 4, a speed sensor 5 connected to a recording unit 6, a load device 7, a rotating electromagnetic powder clutch 8 with a control winding 9 , drive 10, power supply 11, controllable power supply 12. In this case, the load device 7 is mounted on the frame 3. The leading part of the electromagnetic clutch 8 is connected to the drive 10, and the slave to the measuring wheel 1. The drive 10 is connected to the power supply 11. Winding control phenomenon 9 is connected to a controllable power supply unit 12.

The known device operates as follows.

Before taking measurements, the surface of the road surface is moistened. The drive 10 is supplied with power from the power supply 11. The torque from the drive 10 will be transmitted through a gear transmission to a rotating electromagnetic powder clutch 8. The moment of the measuring wheel 1 depends on the magnitude of the control signal of the controlled power supply 12. From the recording unit 6, a control signal is supplied, which smoothly increases the power of the controlled power supply 12 from 0 to a maximum value. The start of slipping of the measuring wheel 1 is detected by the speed sensor 5. The signal from the speed sensor 5 is transmitted to the registration unit 6, in which the start of slipping and the value of the control signal corresponding to the moment, which is transmitted to the measuring wheel 1 through a rotating electromagnetic powder clutch 8, are recorded. The moment transmitted by the rotating electromagnetic powder clutch 8 is directly proportional to control signal of the registration unit 6. The clutch coefficient is determined by the moment required to bring the measuring wheel 1 from a standstill to axle box mode education. To obtain reliable data on the magnitude of the coefficient of adhesion before using the device, it is necessary to obtain experimentally the dependence of the magnitude of the control signal on the magnitude of the coefficient of adhesion. To do this, measure in areas with a known coefficient of adhesion and record the magnitude of the signal going to the control winding 9 of the rotating electromagnetic powder clutch 8.

A disadvantage of the known device prototype is:

- a significant limit of permissible absolute measurement error, which is explained by the complexity of determining the beginning of the slipping of the measuring wheel;

- operating temperature range + 1 ... + 50 degrees. Measurements are carried out only in the summer, since the investigated surface of the pavement requires moisture.

The aim of the proposed device (figure 2) is to increase the accuracy of measuring the coefficient of adhesion by introducing two torque sensors: a sensor for measuring the moment of force (Mg) of the adhesion of the measuring wheel to the surface of the artificial coating and a sensor for measuring the moment of force (M) of braking of the measuring wheel with an electromagnetic brake. Direct measurement and then comparison of the moments of adhesion force (Mg) and braking force (M) allows you to more accurately determine the start of slipping of the measuring wheel and the range of the specified slip, which increases the accuracy of measuring the coefficient of adhesion.

The goal in the "Portable device for measuring the coefficient of adhesion of the wheel with artificial turf" is achieved by the fact that it, as in the prototype, contains: a measuring wheel, a frame, a registration unit, a power supply and a controllable power supply. In this case, the first output of the registration unit is connected to the first input of the controlled power supply,

Additionally, the device includes: first and second torque sensors, electromagnetic brake, angular velocity sensor, time sensor with display and memory unit. In this case, the first mechanical output of the measuring wheel is connected to the first torque sensor, the first and second outputs of which are respectively connected to the first and second inputs of the registration unit. The second mechanical output of the measuring wheel through the second torque sensor is connected to the rotor of the electromagnetic brake. The power supply through a controllable power supply is connected to an electromagnetic brake. The angular velocity, time and second torque sensors are connected respectively to the third, fourth and fifth inputs of the registration unit, the second and third outputs of which are respectively connected to the display and the memory unit. The sixth free input of the registration unit is the input of the dynamometer of the roller brake stand. In this case, the first torque sensor measures the moment of force (Mg) of adhesion of the measuring wheel with the surface of the artificial coating, and the second torque sensor measures the moment of force (M) of braking of the measuring wheel. The equipment of the device is placed on a frame that rests on the measuring wheel and acts on the surface of the artificial coating as a normal load force P. The adhesion coefficient is determined provided that M-Mg = ΔM, and is calculated by the formula

KSCP. = F / P; F = Mg / r;

Kstsp.maks. = Kstsp × k; k = Mg * / Mg;

where is KSCP. - the value of the coefficient of adhesion;

Kstsp.maks. - the maximum value of the coefficient of adhesion;

F is the adhesion force of the measuring wheel to the surface of the artificial coating, N;

P is the normal load force of the measuring wheel on the surface of the artificial turf, N;

Mg is the moment of adhesion of the measuring wheel to the surface of the artificial coating, Nm;

M is the moment of braking force of the measuring wheel with an electromagnetic brake, Nm;

ΔМ - discrete moment of force, providing the beginning of the slipping of the measuring wheel, Nm;

r is the radius of the measuring wheel, m;

k is the slip coefficient, calculated by taring the device;

Mg * - maximum moment of adhesion force of the measuring wheel with the surface of the artificial coating, Nm.

In the known technical solutions, features similar to the distinguishing features of the claimed device are not found, as a result of which it can be considered that the proposed device corresponds to the inventive step.

The use of this device in its implementation will improve the accuracy of determining the coefficient of adhesion on artificial turf, create portable devices that can be used in the operation and repair of road surfaces, in the investigation of road traffic accidents, and also monitor the condition of artificial surfaces of roads and airfields.

The essence of the proposed "Portable device for measuring the coefficient of adhesion of the wheel with artificial turf" is illustrated by drawings, which show:

figure 1 is a structural diagram of a prototype;

figure 2 is a structural diagram of the proposed device;

figure 3 - algorithm for measuring the coefficient of adhesion of the wheel with artificial turf;

figure 4 explains the operation of the first 13 and second 14 torque sensors.

The proposed "Portable device for measuring the coefficient of adhesion of the wheel with artificial turf", as a prototype, contains: measuring wheel 1, frame 3, registration unit 6, power supply 11 and a controlled power supply 12. In this case, the first output of the registration unit 6 is connected to the first input of the controlled power supply 12,

Additionally, the device includes: first 13 and second 14 torque sensors, electromagnetic brake 15, angular velocity sensor 16, time sensor 17 with a display 18 and a memory unit 19. In this case, the first mechanical output of the measuring wheel 1 is connected to the first 13 torque sensor, the first and second outputs of which are respectively connected to the first and second inputs of the registration unit 6. The second mechanical output of the measuring wheel 1 is connected to the rotor of the electromagnetic brake 15 through a second torque sensor 14. 11 through a controlled power supply 12 is connected to an electromagnetic brake 15. The angular velocity sensors 16, time 17 and the second torque sensor 14 are connected respectively to the third, fourth and fifth inputs of the recording unit 6, the second and third outputs of which are respectively connected to the display 18 and the memory unit 19. The sixth free input of the registration unit 6 is the input of the dynamometer of the roller brake stand. In this case, the first torque sensor 13 measures the moment of force (Mg) of adhesion of the measuring wheel 1 to the surface of the artificial turf. The second torque sensor 14 is the braking torque (M) of the measuring wheel 1. The device’s equipment is placed on the frame 3, which rests on the measuring wheel 1 and acts on the surface of the artificial coating as a normal load force R. The adhesion coefficient is determined under the condition that M- Mg = ΔM, and is calculated by the formula

KSCP. = F / P; F = Mg / r;

Kstsp.maks. = Kstsp × k; k = Mg * / Mg;

where is KSCP. - the value of the coefficient of adhesion;

Kstsp.maks. - the maximum value of the coefficient of adhesion;

F is the adhesion force of the measuring wheel to the surface of the artificial coating, N;

P is the normal load force of the measuring wheel on the surface of the artificial turf, N;

Mg is the moment of adhesion of the measuring wheel to the surface of the artificial coating. Nm;

M is the moment of braking force of the measuring wheel with an electromagnetic brake, Nm;

ΔМ - discrete moment of force, providing the beginning of the slipping of the measuring wheel, Nm;

r is the radius of the measuring wheel, m;

k is the slip coefficient, calculated by taring the device;

Mg * - maximum moment of adhesion force of the measuring wheel with the surface of the artificial coating, Nm.

The design of the proposed device

The claimed portable device is made on one measuring wheel 1, on which the frame 3 is mounted. The measuring wheel 1, frame 3 and the device equipment located on it make up the normal force (P) of the load of the measuring wheel 1 on the surface of the artificial coating. The normal force P is known and remains constant during operation of the device. The normal force P is stored in the memory of the registration unit 6 to calculate the coefficient of adhesion.

- Measuring wheel 1 - aircraft or automobile chassis through a second sensor 14 is connected to the rotor of the electromagnetic brake 15.

- The first torque sensor 13 is located on the measuring wheel 1 and is used to measure the moment of force (Mg) of adhesion of the measuring wheel 1 with the surface of the artificial turf. The sensor 13 is equipped with a telemetric system for transmitting a useful signal. The sensor 13 has two outputs, the first output transmits a moment of force (Mg), the second - the frequency of rotation of the measuring wheel 1. The first and second outputs of the torque sensor 13 are connected respectively to the first and second inputs of the recording unit 6.

- A second torque sensor 14 is located between the measuring wheel 1 and the electromagnetic brake 15 and is used to measure the braking force (M) of the braking of the measuring wheel 1. The force moment (M) applied between the ends of the shaft of the torque sensor 14 (between the measuring wheel 1 and the rotor electromagnetic brake 15), creates a mechanical deformation, which is measured by the bridge tensometric system. The moment of force (M), proportional to the torque of the electromagnetic brake 15, is fed to the fifth input of the registration unit 6.

- The electromagnetic brake 15 has two coaxial elements: a housing containing an electromagnet coil and an internal rotor separated from the housing by an annular gap. The annular gap contains ferromagnetic powder, which becomes active when an electromagnet is excited. An excited coil of an electromagnet creates a drive bundle between the rotor and the housing. The power of the drive ligament depends on the value of the direct current supplied to the coil of the electromagnetic brake 15 from the power supply 11. The moment of force (M) transmitted by the electromagnetic brake 15 is directly proportional to the excitation current and is changed by a steplessly controlled power supply 12 in accordance with the control signals of the registration unit 6 The rotation speed of the measuring wheel 1 does not affect the moment of force (M) transmitted by the electromagnetic brake 15. The moment of force (M) for the portable device is selected within 30 ... 50 Nm. For devices that determine the condition of the road surface or the runway of the aerodrome, the moment of the braking type of the electromagnetic brake is selected in accordance with the normal load on the measuring wheel.

- Angular velocity sensor 16 - piezoceramic gyroscope - designed to determine rotation angles and the presence of vibration of the device, has a high response speed, compact. The information of the angular velocity sensor 16 is fed to the third input of the registration unit 6, and then, in accordance with the software of the registration unit 6, supplements information about the state of the artificial coating and the memory unit 19 is recorded.

- The time sensor 17 with a display 18 has its own power source, which provides operational work with the device when the portable device is often turned off and on. Information from the time sensor 17 enters the registration unit 6. The display 18 shows the real time and information about the technical condition of the device coming from the second output of the registration unit 6.

- The memory block 19 is made on a non-volatile memory chip. In the memory block 19 is recorded: date, time, KSPP., KSPP.maks., Speed V, distance S, rotation angles, the presence of vibration. For a detailed analysis of the measurements, the memory unit 19 is removed and connected to a personal computer.

- The registration unit 6 is made on a microcontroller of the PIC18 family. The microcontroller has programmable memory, random access memory, analog-to-digital converters, built-in interfaces, timers, real-time timer, inputs and outputs for input and output of information.

- Managed power supply 12 is a power unit, which, according to the control signals of the registration unit 6 generates a field current of the winding of the electromagnet of the electromagnetic brake 15.

Device taring

Calibration of the device is carried out during its manufacture, and then with a frequency determined by the operating instructions for this device. Calibration of the device is carried out in order to verify the correct operation of the device - compliance with the technical parameters laid down, the accuracy of determining the coefficient of adhesion (KSCP.), Determine the slip coefficient (k) to calculate the maximum value of the coefficient of adhesion (KSCP.max.). For taring use a roller brake stand. The roller brake stand contains: a frame on which the roller unit, an electric motor, a balanced gearbox and force sensors are placed. The measurement results are sent to a dynamometer. The force sensors determine the normal force (P) of the pressure of the measuring wheel 1 on the roller unit. The rollers of the roller assembly are coated with friction material with a known coefficient of adhesion. The rollers of the roller unit are driven by an electric motor through a balanced gearbox. The frame of the balanced gearbox under the action of a reactive moment proportional to the braking force moment (M) of the measuring wheel 1 rotates and acts on the dynamometer. According to the testimony of the brake stand dynamometer, a conclusion is drawn on the traction force (F) of the measuring wheel coated with a roller assembly.

Device calibration method

The measuring wheel is mounted on a roller assembly. Turn on the device taring mode. To the free input 6 of the registration unit 6 connect the dynamometer of the roller brake stand. The force sensors determine the normal pressure force P of the measuring wheel 1 on the roller unit. Turn on the electric motor of the brake stand. The rollers of the roller unit begin to rotate, the measuring wheel 1 also starts to rotate, while the translational speed of the measuring wheel 2 ... 2.5 km / h.

The excitation current of the electromagnet of the electromagnetic brake 15 is increased, respectively, the braking force of the measuring wheel 1 increases. The torque sensor 13 determines the torque (Mg) of the clutch of the measuring wheel 1 with the roller surface of the roller assembly. Under the condition M-Mg = ΔM, a further increase in the excitation current of the electromagnet of the electromagnetic brake 15 stops. ΔМ is the moment of force corresponding to the initial slip of the measuring wheel 1. The adhesion force (F) of the measuring wheel 1 to the roller surface of the roller assembly F = Mg / r is determined (r is the radius of the measuring wheel). If the adhesion force (F) is equal to the readings of the brake stand dynamometer, the torque sensors 13 and 14 are serviceable and correspond to the technical conditions. Therefore, the coefficient of adhesion calculated by the formula (KSCP. = F / P) has a reliable value.

To determine the maximum value of the coefficient of adhesion (Kstsp.maks.) Determine the coefficient of slipping (k). Why, with the initial slip (ΔM) of the measuring wheel 1, the value of the moment of force (Mg) is stored. Then, increase the braking moment of force (M) by the electromagnetic brake 15, determine the maximum value of the moment of force (Mg *) of the clutch of the measuring wheel 1. The maximum value of the moment of force (Mg *) is stored. (The maximum value of the moment of force (Mg *) is determined at a translational speed of rotation of the measuring wheel 1 equal to 65 km / h.) The slip coefficient (k) is equal to the ratio of the maximum value of the moment of force (Mg *) to the moment of force (Mg)

k = Mg * / Mg.

The maximum value of the coefficient of adhesion is calculated by the formula

Kstsp.maks. = Kstsp × k.

The speed of the device is determined, according to the speed obtained, taking into account the speed of movement of the device, the adhesion coefficient determination period (T) is set.

Device operation

Before determining the coefficient of adhesion, preparatory work is carried out: the date, time of the measurement are set, the "measurement" mode is turned on (Figure 3).

The speed of the device when measuring the coefficient of adhesion is determined arbitrarily and can be set from 0.5 to 65 km / h, a change in speed at the time of measurement does not affect the quality of determination of the coefficient of adhesion. During the measurements, stops are possible, while the information about the state of the road surface obtained before the stop is stored. With the resumption of movement, the cohesion coefficient counting continues from previously recorded information. With the beginning of movement in each measurement period (T), the current of the electromagnetic coil excitation coil increases in accordance with the control signals of the recording unit 6. With increasing the excitation current, the braking torque (M) of the electromagnetic brake 15 proportionally increases. The braking torque (M) has a braking effect on the measuring wheel 1.

The torque of the braking force (M) acting on the measuring wheel 1 is measured by the torque sensor 14. The measured braking force moment (M) enters the registration unit 6. At the same time, the torque sensor 13 measures the moment of force (Mg) of the adhesion of the measuring wheel 1 to the surface of the artificial turf. The moment of adhesion force (Mg) enters the registration unit 6. In the registration unit 6, the moment of adhesion force (Mg) is compared with the moment of braking force (M). If the moment of adhesion force (Mg) is greater than the moment of braking force (M) (Mg> M), then the slipping of the measuring wheel 1 is absent. In this case, the influence of the control signals of the recording unit 6 on the controlled power supply 12 increases the excitation current of the electromagnet of the electromagnetic brake 15. The braking torque (M) of the measuring wheel 1 increases. When the braking force (M) is greater than the clutch torque (Mg) (Mg) <M), the increase in the excitation current of the electromagnet stops. This ensures the start of slipping of the measuring wheel 1 when М-Mg = ΔМ, ΔМ is the moment of force of the specified start of slipping, which is supported by the control signals of the registration unit 6. When the condition M-Mg = ΔМ is fulfilled, the adhesion force (F) of the measuring wheel is calculated for 1 s artificial coating surface F = Mg / r (r is the radius of the measuring wheel 1). The normal pressure force (P) of the measuring wheel 1 on the coating surface is known. The coefficient of adhesion is calculated. Kstsp. = F / R.

When determining the condition of the runway in accordance with the requirements of ICAO (International Civil Aviation Organization), the maximum coefficient of adhesion is determined, which is calculated by the formula Ksst.max. = Ksts. × k,

where k is the slip coefficient determined during calibration of the device.

From the second output of the torque sensor 13 in the registration unit 6 receives a signal of the frequency of rotation of the measuring wheel, which determines the speed (V) and the distance traveled (S). The speed of the device is determined by the formula V = ω × r,

where V is the speed of movement, m / s;

ω is the angular speed of rotation of the measuring wheel 1, rad / s;

r is the radius of the measuring wheel 1, m

The distance traveled is determined by the formula S = Vt,

where S is the distance traveled when determining the state of artificial turf, m;

V is the speed of movement, m / s;

t is the measurement time, sec.

Wetting artificial turf when determining the coefficient of adhesion is not required. By the control signals of the registration unit 6, in accordance with the software, the braking force moment (M) is changed by ΔM. Changing the braking force moment (M) is shown in FIG. Changing the braking torque (M) by a predetermined amount (ΔM), at which the initial slipping of the measuring wheel is ensured, allows you to constantly monitor the magnitude of the moment of force (Mg) of adhesion to the surface of the artificial turf. Changing the braking torque (M) by ΔM also slightly reduces the thermal effect on the measuring wheel 1.

When determining the coefficient of adhesion, the following is recorded in the memory unit: date, time of measurements, value of the coefficient of adhesion, speed, measured distance, the presence of turns and vibration.

The positive effect of the implementation of the proposed device is to increase the accuracy of determining the coefficient of adhesion. Measurement accuracy is enhanced by using two torque sensors simultaneously. The first sensor 13 measures the moment of adhesion force (Mg), and the second sensor 14 measures the braking moment (M) of the measuring wheel 1. The measurement results of the sensors are compared. According to the results of the comparison, the electromagnetic brake 15 is controlled. As a result, the electromagnetic brake 15 monitors the start of slipping of the measuring wheel 1 in a predetermined range (ΔM), increasing the accuracy of determining the coefficient of adhesion.

Implementation of the proposed structural diagram of the device allows you to create a portable device of small size, weighing 20 ... 25 kg, with a braking force of 30 ... 50 Nm, which can be used in the repair of road surfaces or in the investigation of traffic accidents. Or to create large-sized devices that move using a vehicle and are used to determine the condition of road or airfield coatings.

Structurally, the device can be made of the following parts:

- measuring wheel 1 - automobile or aircraft chassis;

- the first torque sensor 13 is a torque sensor M28;

- the second torque sensor 14 is a non-contact torque sensor, model 8651;

- electromagnetic brake 15 - magnetic powder brake with a hollow shaft, type FAT, FRAT, company Mobac GmbH, Germany;

- controlled power supply 12 - a typical power unit that converts control signals into the excitation current of the electromagnet winding;

- registration unit 6 - microcontroller family PIC18,

authors B.Ya. Prokhorenko et al. M. DODEKA, 1999;

- memory block 19 - non-volatile memory chip;

- angular velocity sensor 16 - piezoceramic gyroscope ENC-03J from Murata.

Claims (1)

A portable device for measuring the coefficient of adhesion of an artificial-coated wheel, comprising a measuring wheel, a frame, a registration unit, a power supply and a controllable power supply, the first output of the registration unit being connected to the first input of the controllable power supply, characterized in that the first and the second torque sensors, electromagnetic brake, angular velocity sensor, time sensor with display and memory unit, while the first mechanical output of the measuring wheel is connected with a first torque sensor, the first and second outputs of which are respectively connected to the first and second inputs of the registration unit, and the second mechanical output of the measuring wheel through the second torque sensor is connected to the electromagnetic brake rotor, the power supply is connected to the electromagnetic brake via a controlled power supply, sensors angular speed, time and a second torque sensor are connected respectively to the third, fourth and fifth inputs of the registration unit, the second and third outputs of the cat They are respectively connected to the display and the memory unit, the sixth free input of the registration unit is the input of the dynamometer of the brake brake stand, while the first torque sensor measures the moment of force (Mg) of adhesion of the measuring wheel to the surface of the artificial coating, and the second torque sensor measures the moment of force ( M) braking of the measuring wheel, the device equipment is placed on a frame that rests on the measuring wheel and acts on the surface of the artificial coating as normal forces load P, the friction coefficient is determined under the condition that M-Mg = ΔM and calculated by the formula
CSCP = F / P; F = Mg / r;
Kstsp.maks. = Kstsp · k; k = Mg * / Mg,
where is KSCP. - the value of the coefficient of adhesion;
Kstsp.maks. - the maximum value of the coefficient of adhesion;
F is the adhesion force of the measuring wheel to the surface of the artificial coating, N;
P is the normal load force of the measuring wheel on the surface of the artificial turf, N;
Mg is the moment of adhesion of the measuring wheel to the surface of the artificial coating, Nm;
M is the moment of braking force of the measuring wheel with an electromagnetic brake, Nm;
ΔM - discrete moment of force, providing the beginning of the slipping of the measuring wheel, Nm;
r is the radius of the measuring wheel, m;
k is the slip coefficient, calculated by taring the device;
Mg * - maximum moment of adhesion force of the measuring wheel with the surface of the artificial coating, Nm.

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