DE102022133852A1 - Compressor control method for a piston compressor motor of a piston compressor and compressor control for carrying out the method as well as compressor system and vehicle therewith - Google Patents

Abstract

The invention relates to a compressor control method (100) for a piston compressor motor (26) of a piston compressor (24). To start the piston compressor motor (26), the piston compressor motor (26) is initially operated at a predefined starting rotation frequency (114) during a measuring phase (118). A performance parameter (122) of the piston compressor is measured for at least one full revolution (61) of the piston compressor motor (26) to obtain a performance parameter curve (130) of the piston compressor (24) during. This is followed by determining a performance parameter characteristic (140) in the measured performance parameter curve (130) and continuing or re-operating the piston compressor motor (26) at the starting rotation frequency (114) and continuing or re-measuring the performance parameter (122) in an identification phase (148) until the determined performance parameter characteristic (140) of the measured performance parameter (11) is recognized. When or after the performance parameter characteristic (140) is recognized, the piston compressor motor (26) continues to operate at an operating rotation frequency (174) in an operating phase (171) or the piston compressor motor (26) is stopped and the piston compressor motor (26) is operated again at the operating rotation frequency (174) in the operating phase (171) after stopping. The operating rotation frequency (174) is greater than the starting rotation frequency (114).
The invention further relates to a compressor control (27), a compressor system (10) with a piston compressor motor (26) and a compressor control (28) and a vehicle (16) with a compressor control (28).

Description

The present invention relates to a compressor control method for a reciprocating compressor motor of a reciprocating compressor. Furthermore, the invention relates to a compressor controller for carrying out the compressor control method, a compressor system with the compressor controller and a vehicle with the compressor system.

In general, the invention relates to piston compressors of vehicles that are designed as commercial vehicles or passenger cars. The piston compressors considered here, in particular as part of a compressor system, are used to supply compressed air to a pneumatic system of the vehicle. Such a compressed air supply is required in a vehicle, for example, to supply a braking system in order to actuate friction brakes of the braking system using compressed air. Furthermore, compressed air is required in a vehicle with an air suspension system to supply air springs in order to enable a spring function of the vehicle and in some cases also a level control or level adjustment of the vehicle using compressed air.

The known piston compressors are designed for their use in accordance with the state of the art. This includes, for example, that a piston compressor motor is designed in such a way that it can generate a corresponding torque for operation within an application area of the piston compressor to generate a predefined operating compression power or target pressure power. Since it is known that the torque of electric motors is dependent on the speed, a piston compressor motor must be designed in such a way that it enables the piston compressor to start at a low speed. In some positions of a piston of the piston compressor, a high power is required for the piston compressor motor in order to reliably guarantee the torque for starting.

However, for reasons of cost or space, piston compressor motors are usually designed in such a way that under certain operating conditions a pressure is built up in a piston-cylinder arrangement of the piston compressor during the start-up process, which, given the prevailing torque, leads to the piston compressor motor coming to a standstill during the start-up process with a low starting speed. In such a situation, the piston compressor motor is then switched off briefly and restarted after a transition period in which the pressure conditions have changed for another start-up process. The piston compressor can then start successfully on the second start attempt.

Switching off the piston compressor motor often leads to a banging noise, which is caused by the piston hitting back when it is switched off. This noise is undesirable and can make a driver uncertain about the vehicle's roadworthiness, especially if it only occurs occasionally due to certain circumstances. In addition, briefly switching off the piston compressor motor can also lead to an error entry in an error log, which is also undesirable.

As a measure to avoid such noises, if necessary, electric motors are used as piston compressor motors, which actually provide too much power for the required operation, i.e. are oversized. As already mentioned above, these piston compressor motors are comparatively more expensive and require a comparatively larger installation space.

The object of the present invention is therefore to address the problems of the prior art. In particular, the use of an oversized electric piston compressor motor in a piston compressor is to be avoided and at the same time noises that occur in certain situations due to an unsuccessful start of the piston compressor are to be counteracted. In any case, an alternative to what is known from the prior art is to be found.

To this end, the invention relates to a compressor control method for a piston compressor motor of a piston compressor which can be used in a vehicle, in particular in a commercial vehicle or a passenger car.

The compressor control method according to the invention for a reciprocating compressor motor of a reciprocating compressor comprises the following steps for starting the reciprocating compressor motor.

First, the piston compressor motor is operated with a predefined starting rotation frequency during a measuring phase. Accordingly, a measuring phase is defined and the piston compressor motor, in particular after a standstill of the piston compressor motor, is operated with a certain speed, namely the predefined starting rotation frequency. While the piston compressor motor is operated with the predefined starting rotation frequency in the measuring phase, a performance parameter of the piston compressor, in particular of the Piston compressor motor, measured for at least one full revolution of the piston compressor motor. One full revolution corresponds to one revolution of a drive shaft of the piston compressor motor by 360°.

By measuring the performance parameter, a performance parameter curve is obtained or determined. The performance parameter curve therefore includes the curve, in particular the temporal curve, of the performance parameter during at least one full revolution of the piston compressor motor. The performance parameter curve corresponds in particular to a current curve or a voltage curve of the piston compressor motor.

In the next step, after obtaining the performance parameter curve, a performance parameter characteristic is determined in the performance parameter curve. The performance parameter characteristic is determined during the measurement phase or after the measurement phase in an identification phase.

Furthermore, the operation of the piston compressor motor is continued at the starting rotation frequency and the measurement of the performance parameter is continued in an identification phase following the measurement phase. Alternatively, the identification phase can also begin after an interim stop of the piston compressor motor at the end of the measurement phase. The operation of the piston compressor motor is then resumed according to the alternative at the starting rotation frequency and the performance parameter is measured again. In the identification phase, the piston compressor motor is then operated in the identification phase until the specific performance parameter characteristic of the measured performance parameter is recognized.

After or, in particular, exactly when the performance parameter characteristics are recognized, the piston compressor motor is then either continued to operate at an operating rotation frequency or the piston compressor motor is stopped and, after stopping, operated again at the operating rotation frequency.

The operating rotation frequency is greater than the starting rotation frequency. The operating rotation frequency therefore corresponds to a speed of the piston compressor motor that is greater than a speed that corresponds to the starting rotation frequency.

The invention is based on the finding that a position of a piston of the piston compressor can be identified using a performance parameter of the piston compressor motor. By measuring the performance parameter during at least one full revolution, characteristic points of the performance parameter can be identified using the performance parameter curve, which correspond to a position, namely a specific angle of rotation of the piston compressor motor. The characteristic points appear periodically in the performance parameter curve with the period of a full revolution.

The performance parameter characteristic is determined and the performance parameter characteristic is recognized using a starting rotation frequency that is predefined in such a way that the piston compressor motor is prevented from stopping due to insufficient torque. However, the starting rotation frequency is preferably constant during the at least one full revolution for determining the performance parameter curve, so that a changing starting rotation frequency is not reflected in values of the performance parameter.

Now that the performance parameter characteristic has been determined, it is possible to determine exactly the point in time or angle of rotation at which the previously determined performance parameter characteristic reappears in the measured performance parameter by continuing to operate the piston compressor motor at the starting rotation frequency and simultaneously measuring the performance parameter.

If the performance parameter characteristic is selected or identified as the exact point in time or angle of rotation at which the piston has a certain position that promises a successful start of the piston compressor motor, the piston compressor motor can continue to operate at the normal operating rotation frequency from exactly this point in time or angle of rotation. Successful starting of the piston compressor without multiple start attempts is thus possible, so that the piston compressor then delivers an operating compression output.

If the performance parameter characteristic is selected or identified as a point in time or angle of rotation at which the piston does not yet have a certain position that promises a successful start of the piston compressor motor, the piston compressor motor can initially continue to operate at the starting rotation frequency for a predefined angle of rotation or a predefined period of time until another point in time or another angle of rotation is reached that promises a successful start of the piston compressor motor. From this further point in time or from this further angle of rotation, which is after the performance parameter characteristic has been identified, the piston compressor motor can then continue to operate at the normal operating rotation frequency. This also makes it possible to start the piston compressor successfully without having to make multiple start attempts.

Alternatively, when or after the performance parameter characteristics are detected, the piston compressor motor can initially be stopped and, if required, continued to operate directly from this position at the operating rotation frequency.

This prevents the piston compressor motor from failing to start, i.e. stopping during the start-up process. At the same time, it is preferable to avoid over-dimensioning the piston compressor motor to ensure a successful start-up process.

According to a first embodiment, the operating rotation frequency or an operating rotation frequency range in which the operating rotation frequency lies is defined as a speed or speed range with which or in which the piston compressor generates a predefined operating compression power. The predefined operating compression power corresponds, for example, to compressed air with a relative pressure in the range from 5 bar to 20 bar or in the range from 6 bar to 12 bar.

Accordingly, the operating rotation frequency corresponds to a speed at which the piston compressor is operated during operation, in particular in an application for which the piston compressor motor is designed. The operating rotation frequency can also be in an operating rotation frequency range that corresponds to a speed range in which the piston compressor delivers an operating compression power range, for example in a target range. The operating rotation frequency can also be referred to as the target rotation frequency or target speed. With this speed, the piston compressor generates a predefined operating compression power. The operating compression power can accordingly be referred to as the target compression power of the piston compressor and is preferably predefinable.

The target compression power is preferably used to provide compressed air with a relative pressure in the range of 5 bar to 20 bar. This pressure is particularly suitable for supplying an air suspension system. Alternatively, operating the piston compressor motor at the operating rotation frequency provides an operating compression power that corresponds to providing compressed air with a relative pressure in the range of 6 bar to 12 bar. The compressed air is used to supply a pneumatic system, which can also be called a compressed air system and in particular corresponds to or is part of a compressed air brake system or an air suspension system of a vehicle.

According to a further embodiment, the starting rotation frequency is set by specifying a frequency for commutation of the piston compressor motor with a compressor control. Setting the frequency for commutation with a compressor control serves to precisely determine and in particular to keep the starting rotation frequency constant, so that it can be ensured that a changing starting rotation frequency has no influence on the performance parameter.

According to a further embodiment, the invention comprises that the piston compressor motor is a brushless DC motor, namely a so-called BLDC motor, or a controlled DC motor. The compression control method is used especially for these types of piston compressor motors to ensure a safe start, while at the same time performance parameters of the piston compressor motors are particularly suitable for identifying a performance parameter characteristic that corresponds to a defined position of a piston of the piston compressor and to ensure a predefined, preferably constant, starting rotation frequency.

According to a further embodiment, the piston compressor is of the sleeve compressor type. This means that at least one sealing element in a piston-cylinder arrangement of the piston compressor is designed as a sleeve. The seal of a sleeve compressor preferably has an asymmetrical sectional shape at least in the area outside a groove in which the seal is connected to the piston. A sleeve is preferably a seal that has a geometric design in which a coefficient of friction between a cylinder of the piston-cylinder arrangement and a piston of the piston-cylinder arrangement in a lifting phase of the cylinder differs from a coefficient of friction in a lowering phase of the cylinder. A sleeve is designed, for example, as a funnel-shaped ring, so that a movement of the piston in the direction in which the funnel tapers has less resistance on the cylinder than when the piston moves in the opposite direction.

In the case that the piston compressor is of the sleeve compressor type, the starting rotation frequency is predetermined as a speed at which an air pressure in the cylinder of the piston-cylinder arrangement of the piston compressor remains substantially constant during at least one full revolution of the piston compressor motor. Preferably, a substantially constant air pressure is assumed when the air pressure or relative pressure of the air remains below 1% of the relative pressure of the operating compression capacity.

Due to the seal designed as a sleeve of a sleeve compressor, even at essentially constant air pressure, which prevails at a very low speed of the piston compressor motor, a performance parameter curve, namely, for example, a current curve or a voltage curve, can be measured on the piston compressor motor, which differs at least in the time range of a lifting phase from the performance parameter curve in a time range of a lowering phase. The lowering phase corresponds, for example, to a movement of the piston in which the piston moves from one dead center, for example the top dead center, to the other dead center, for example the bottom dead center. The lifting phase corresponds, for example, to a movement of the piston in which the piston moves in the other direction.

This means that the dead points in the performance parameter curve can be clearly identified as characteristic values of the performance parameter and the position of the piston can be determined based on the performance parameter curve. Likewise, by defining the performance parameter characteristics, for example as a characteristic curve or value of the performance parameter in one of the dead points, a suitable starting position for the piston compressor can be determined in order to enable a safe start of the piston compressor.

According to a further embodiment, the piston compressor is of the type of a sleeve compressor or a piston ring compressor. In contrast to a sleeve compressor, the piston ring compressor is a compressor in which at least one seal is designed such that in both possible directions of movement of the piston-cylinder arrangement there are essentially the same coefficients of friction between the piston and cylinder of the piston-cylinder arrangement. The seal of a piston ring compressor preferably has a symmetrical sectional shape at least in the area outside a groove in which the seal is connected to the piston.

According to this embodiment, the starting rotation frequency is predetermined as the speed at which the air pressure in the piston-cylinder arrangement generates at least 1% and a maximum of 5% to 20% of the operating compression power during at least one full revolution of the piston compressor motor. Accordingly, the piston compressor is operated in such a way that a low relative pressure builds up in the piston-cylinder arrangement while the piston moves in its compression direction. The compression direction corresponds, for example, to a stroke phase. By building up the pressure, it is ensured that a load on the piston compressor motor increases as the pressure increases. A performance parameter reflects this. At least the point at which the maximum pressure is built up in the piston-cylinder arrangement and the direction of movement of the piston of the piston-cylinder arrangement is reversed in order to increase the volume in the piston-cylinder arrangement again, for example in a lowering phase.

In this way, even in reciprocating compressors of the sleeve compressor type or the piston ring compressor type, the position of the piston can be detected using the performance parameter to find a suitable starting position for continuing to operate the reciprocating compressor motor at the operating rotation frequency or stopping the reciprocating compressor motor to continue to operate the reciprocating compressor motor at the operating rotation frequency.

According to a further embodiment, the power parameter corresponds to a current consumed by the piston compressor motor or a voltage drop across the piston compressor motor.

According to this embodiment, in the case where the power parameter is a current consumed by the reciprocating compressor motor, the power parameter characteristic is a current characteristic of the consumed current. The power parameter characteristic corresponds to a maximum or minimum current value in the current characteristic or a current characteristic in the range of the maximum or minimum current value in the current characteristic.

According to the alternative that the performance parameter corresponds to a voltage drop across the piston compressor motor, the performance parameter curve is the voltage curve of the voltage drop across the piston compressor motor. The performance parameter characteristic then corresponds to a minimum or maximum voltage value in the voltage curve or a voltage curve characteristic in the range of the minimum or maximum voltage value.

By considering the current consumed by the reciprocating compressor motor during operation at the starting rotation frequency or the voltage dropped across the reciprocating compressor motor during operation at the starting rotation frequency, one can determine the torque that the reciprocating compressor motor must provide during rotation.

By realizing that certain positions are characteristic of corresponding positions of the piston, the position of the piston can be determined in a simple manner. For example, shortly before a position, such as shortly before reaching top dead center, of the piston-cylinder arrangement in which the volume in the piston-cylinder arrangement is essentially at its lowest, a comparatively high torque is required. This torque is characteristically distinguished from other positions in the current curve or the voltage curve. A position of the piston for a successful start can thus be recognized without additional effort, since the performance parameters current and voltage of the piston compressor motor are preferably available for evaluation in a compressor control system anyway.

According to a further embodiment, the performance parameter corresponds to a relative pressure generated by the piston-cylinder arrangement. The relative pressure is measured, for example, at a pressure output or pressure outlet of the piston-cylinder arrangement. The performance parameter curve then corresponds to a pressure curve of the generated relative pressure and the performance parameter characteristic corresponds to a maximum, minimum or constant relative pressure in the pressure curve or a pressure curve characteristic in the range of the maximum, minimum or constant relative pressure.

By monitoring the relative pressure, it is possible to clearly identify an area in which the pressure is increasing, whereby this area can be referred to as the area in which the piston reduces a volume in the piston-cylinder arrangement. This in turn makes it possible to determine the position of the piston without having to take current and voltage curves into account. The disadvantage of this embodiment is that an additional pressure sensor must be arranged in the pressure path of the piston compressor motor or at the pressure outlet of the piston-cylinder arrangement. This enables a particularly clear determination of the performance parameter characteristics.

According to a further embodiment, the performance parameter characteristic corresponds to a slope. In particular, the performance parameter characteristic corresponds to the longest slope in time before a maximum or a minimum of the performance parameter curve. The performance parameter characteristic indicates through the slope an increase in the current consumed or the falling voltage after each commutation step when a relative pressure in the piston-cylinder arrangement increases in order to continue the rotation of the piston compressor motor. Likewise, a characteristic curve of the voltage or current can thus be determined which, depending on the type of compressor, corresponds to certain positions of the piston of the piston-cylinder arrangement. By considering the slope of a performance parameter characteristic, an exact position of the piston of the piston-cylinder arrangement and/or the angle of rotation of the piston compressor motor can also be determined.

According to a further embodiment, the piston of the piston-cylinder arrangement of the piston compressor has a first position. This first position can preferably be referred to as bottom dead center. In the first position, the volume in the cylinder of the piston-cylinder arrangement of the piston compressor corresponds to a maximum. In addition, the piston of the piston-cylinder arrangement has a second position. The second position can also be defined as top dead center. In the second position, the volume in the cylinder of the piston-cylinder arrangement of the piston compressor corresponds to a minimum. Accordingly, the angle of rotation of the piston compressor motor between the first position and the second position corresponds essentially to 180°. A full revolution of the piston compressor motor therefore comprises an angle of rotation of 360°. The performance parameter characteristic also corresponds to the position of the piston at which the compressor motor assumes a predefined angle of rotation. The predefined angle of rotation preferably corresponds to an angle of rotation in the range of 5° to 0° before reaching or when reaching the second position.

Accordingly, a performance parameter characteristic is predefined that describes a position of the piston shortly before top dead center or at top dead center. This performance parameter characteristic corresponds, for example, to the maximum current value in the current curve. Detecting top dead center is advantageous because shortly after top dead center is reached, namely as soon as the piston compressor motor moves the piston-cylinder arrangement towards bottom dead center, the torque required is comparatively lower. During this movement, the piston compressor motor can be accelerated until the next top dead center is reached in order to generate a torque with the piston compressor motor that ensures safe starting.

According to a further embodiment, the continued operation or stopping of the piston compressor motor after the performance parameter characteristic has been detected is carried out by waiting for a predefined period of time after the time of detection of the performance parameter characteristic. After the expiration of the predefined period of time after the time of detection of the performance parameter characteristic, the Piston compressor motor continues to operate at the operating rotation frequency or is stopped. The predefined period of time is particularly dependent on the starting rotation frequency. According to an alternative, at the time the performance parameter characteristic is recognized, the piston compressor motor continues to rotate for a predefined rotation angle range, i.e. a value of a rotation angle. The piston compressor motor then continues to operate at the operating rotation frequency or is stopped in order to be operated at the operating rotation frequency after stopping. A suitable starting position of the piston can thus be determined, independently of a position that can be easily defined by the performance parameter characteristic.

The invention also relates to a compressor control for controlling a piston compressor motor. The compressor control is designed to carry out a method according to one of the embodiments mentioned.

The invention also relates to a compressor system with a piston compressor motor and a compressor control according to the invention. The piston compressor motor is preferably a brushless DC motor or a controlled DC motor.

According to one embodiment of the compressor system, the compressor system is a braking system or an air suspension system for a vehicle. The piston compressor motor is configured to provide compressed air for a compressed air reservoir of the compressor system.

The invention also includes a vehicle with a compressor control according to the invention or a compressor system according to one of the aforementioned embodiments. The vehicle is preferably designed to carry out a compressor control method according to one of the aforementioned embodiments.

• 1 ein Ausführungsbeispiel eines Kompressorsystems,
• 2 ein weiteres Ausführungsbeispiel eines Kompressorsystems,
• 3 einen Leistungsparameterverlauf und
• 4 die Schritte eines Kompressorsteuerungsverfahrens.

Further embodiments are shown in the following examples.

• 1 an embodiment of a compressor system,
• 2 another embodiment of a compressor system,
• 3 a performance parameter curve and
• 4 the steps of a compressor control process.

1 shows a compressor system 10, which is, for example, a braking system 12 or an air suspension system 14 of a vehicle 16. The compressor system comprises a compressed air reservoir 18 to which several consumers 20 of the compressor system 10 can be connected and supplied with compressed air 22. The reservoir 18 is supplied with compressed air 22 via a piston compressor 24 to supply the consumers 20.

The piston compressor 24 comprises a piston compressor motor 26, which can be controlled via a compressor control 28. The piston compressor motor 26 is, for example, a brushless DC motor 30 or a controlled DC motor 32. The piston compressor motor 26 drives a piston 34 of a piston-cylinder arrangement 36. Ambient air 43 is sucked into a cylinder 42 of the piston-cylinder arrangement 36 through an inlet valve 38, which corresponds to a check valve 40, when the piston compressor motor 26 moves the piston 34 out of the cylinder 42.

A volume 44 of the piston-cylinder arrangement 36 is sealed from the environment in an airtight or essentially airtight manner, apart from the inlet valve 38, by piston rings 46 attached to the piston 34, which run circumferentially around the piston 34. The piston compressor 24 therefore corresponds to a piston ring compressor 45.

Once the piston 34 has been fully extended from the cylinder 42, the piston 34 moves back into the cylinder 42 and, through the piston rings 46 and the inlet valve 38, which is designed as a check valve 40 and closes during this movement, ensures that a relative pressure 48 is built up in relation to the environment in the volume 44 of the piston 34. An outlet valve 50, which is also a check valve 52, is opened by the pressure 48 and allows air to flow into the reservoir 18. The outlet valve 50, designed as a check valve 52, is therefore installed in a fluid path formed with the inlet valve 38 in the opposite closing direction. As soon as the piston 34 is pulled out of the cylinder 42 again, the outlet valve 50 closes due to the pressure of the compressed air in the compressed air reservoir 18.

In 1 the piston 34 of the piston-cylinder arrangement 36 is positioned at a bottom dead center 54, i.e. a first position 56.

2 shows a piston compressor 24, which here corresponds to a sleeve compressor 58 and whose piston 34 is positioned in a second position 60. The piston compressor motor 26 is therefore rotated here by an angle of rotation 59 of 180°. A full revolution 61 thus corresponds to an angle of rotation of 360°. This second position 60 corresponds to a top dead center 62. Compared to the 1 The piston ring compressor 45 shown is the Sleeve compressor 58 is designed with a sleeve seal 64.

3 shows a performance parameter curve 130 of the piston compressor motor 26 during a measurement phase 118. Accordingly, a performance parameter 122 is plotted on the vertical axis and time 66 on the horizontal axis. At time 70, a maximum 72 can be seen, which can also be referred to as performance parameter characteristic 140. The steps for recording the performance parameter curve 130 are described in 4 described.

4 shows the steps of an embodiment of the method 100. According to the method 100, in a step 102 a rotational speed 106 is predetermined at which the air pressure, i.e. the relative pressure 107, in a cylinder 42 of the piston-cylinder arrangement 36 of a piston compressor 24 remains essentially constant during at least one full revolution 61. Alternatively, in step 102 a rotational speed 109 is predetermined at which the air pressure, i.e. the relative pressure 111, in the cylinder 42 of the piston-cylinder arrangement 36 of the piston compressor 24 is in the range of at least 1% and a maximum of 5% to 20% of an operating compression power 104 during at least one full revolution 61. The relative pressure 107, 111 is predefined or determined in step 103 depending on the predefined operating compression power 104. The operating compression power 104 is preferably predefined as a relative pressure 105 in the range from 5 bar to 20 bar or in the range from 6 bar to 12 bar. The rotational speed 106, 109 is converted in step 108 to determine a frequency 110 for commutation of the piston compressor motor 24 of the piston compressor 26. In step 112, the piston compressor motor 24 is then commutationally performed so that a starting rotation frequency 114 is output, with which the piston compressor motor 24 is operated in step 116, which is a step of a measuring phase 118.

In step 120, which is also part of the measuring phase 118, a performance parameter 122 is measured, which corresponds, for example, to a current 124 consumed by the piston compressor motor 24, a voltage drop 126 across the piston compressor motor 24 or a pressure 128 generated by the piston-cylinder arrangement 36, namely a relative pressure 129. This outputs a performance parameter curve 130 which corresponds either to a current curve 132, a voltage curve 134 or a pressure curve 136. In step 138, a performance parameter characteristic 140 is then determined, wherein the performance parameter characteristic corresponds, for example, to a maximum value 142 or a minimum value 144 of a gradient 146 or another characteristic 147 in the performance parameter curve 130. Step 138 is also to be regarded as step 118 of the measuring phase 118.

This is followed by a further phase, referred to as the identification phase 148, in which the piston compressor motor 24 is continued or operated again at the starting rotation frequency 114 in a step 150. In step 152, which is also part of the identification phase 148, the performance parameter 122 is monitored in order to recognize the performance parameter characteristic 140. In step 154, the performance parameter characteristic 140 and a point in time 156 or an angle of rotation 158 for it are recognized. In step 159, the piston compressor motor 24 is continued to operate at the starting rotation frequency from the point in time 156 for a specific period of time 160 or from the angular position 158 by a predefined angle of rotation 162. The identification phase 148 is then completed and the piston of the piston-cylinder arrangement 36 is in a predefined position.

For this reason, in step 164, either the piston compressor motor 24 is stopped and in step 166, the system waits for a predefined period of time 168 or until an event 170 is triggered. Then, in an operating phase 171, the piston compressor motor 24 is operated in step 172 with an operating rotation frequency 174 that lies in an operating rotation frequency range 176. The operating rotation frequency 174 corresponds to a speed 175 of the piston compressor motor 26 with which the piston compressor 24 generates a predefined operating compression power 104 with a predefined relative pressure 105. The operating rotation frequency range 176 corresponds to a speed range 177 of the piston compressor motor 26, for example a target range in which the piston compressor 24 generates a predefined operating compression power 104. Alternatively, after step 159, instead of stopping 164, the piston compressor motor continues to operate directly at the operating rotation frequency 174 in step 178. In both cases, the piston compressor 24 produces the operating compression power 104.

Reference symbol (part of the description)

10

Compressor system

12

Braking system

14

Air suspension system

16

vehicle

18

Compressed air reservoir

20

consumer

22

Compressed air

24

Piston compressor

26

Piston compressor engine

28

Compressor control

30

brushless DC motor

32

controlled DC motor

34

Pistons

36

Piston-cylinder arrangement

38

Inlet valve

40

check valve

42

cylinder

43

Ambient air

44

volume

45

Piston ring compressor

46

Piston rings

48

Pressure

50

outlet valve

52

check valve

54

bottom dead center

56

first position

58

Sleeve compressor

59

Angle of rotation

60

second position

61

full rotation

62

Top Dead Center

64

Cuff seal

66

Time

70

time

72

maximum

100

Compressor control method

102

Step Predetermine speed

104

Operating compression power

105

Relative pressure

106

number of revolutions

107

Relative pressure

108

Step Convert

109

number of revolutions

110

frequency

111

Relative pressure

112

Step

114

Starting rotation frequency

116

Step

118

Measuring phase

120

Step

122

Performance parameters

124

Electricity

126

Tension

128

Pressure

129

Relative pressure

130

Performance parameter history

132

Current flow

134

Voltage curve

136

Pressure curve

138

Step

140

Performance parameter characteristics

142

Maximum value

144

Minimum value

146

pitch

147

Characteristics

148

Identification phase

150

Step

152

Step

154

Step

156

time

158

Angular position

159

Step

160

Length of time

162

angle

164

Step Stop piston compressor motor

166

Wait step

168

Duration

170

Event

171

Operational phase

172

Step

174

Operating rotation frequency

175

number of revolutions

176

Operating frequency range

177

Speed range

178

Step

Claims (15)

Compressor control method (100) for a piston compressor motor (26) of a piston compressor (24), comprising the steps for starting the piston compressor motor (26): a) operating the piston compressor motor (26) with a predefined starting rotation frequency (114) during a measuring phase (118), b) measuring a performance parameter (122) of the piston compressor (24) for at least one full revolution (61) of the piston compressor motor (26) to obtain a performance parameter curve (130), in particular a current curve (132) or a voltage curve (134), of the piston compressor (24) during the measuring phase (118), c) determining a performance parameter characteristic (140) in the measured performance parameter curve (130), d) continuing the operation or re-operating the piston compressor motor (26) with the starting rotation frequency (114) and continuing the measuring or re-measuring the performance parameter (122) in an identification phase (148) until the specific performance parameter characteristic (140) of the measured performance parameter (122) is recognized and e) upon or after the performance parameter characteristic (140) is recognized: - continuing to operate the piston compressor motor (26) at an operating rotation frequency (174) in an operating phase (171) or - stopping the piston compressor motor (26) and re-operating the piston compressor motor (26) at the operating rotation frequency (174) in the operating phase (171) after stopping, wherein the operating rotation frequency (174) is greater than the starting rotation frequency (114). Compressor control method (100) according to Claim 1 , wherein the operating rotation frequency (174) or an operating rotation frequency range (176) in which the operating rotation frequency (174) lies is defined as a speed (175) or speed range (177) of the piston compressor motor (26) with which or in which the piston compressor (24) generates a predefined operating compression power (104), for example compressed air (22) with a relative pressure (105) in the range from 5 bar to 20 bar or in the range from 6 bar to 12 bar. Compressor control method (100) according to Claim 1 or 2 , wherein the starting rotation frequency (114) is set by specifying a frequency (100) for a commutation (112) of the piston compressor motor (26) with a compressor control (28). A compressor control method (100) according to any preceding claim, wherein the reciprocating compressor motor (26) is a brushless DC motor (30) or a controlled DC motor (32). Compressor control method (100) according to one of the preceding claims, wherein the piston compressor (24) is of the type of a sleeve compressor (58), and wherein the starting rotation frequency (114) is predetermined as a speed (106) at which a relative pressure (107) in a cylinder (42) of a piston-cylinder arrangement (36) of the piston compressor (24) remains substantially constant, preferably below 1% of the operating compression power (104), during at least one full revolution (61) of the piston compressor motor (26). Compressor control method (100) according to one of the Claims 1 until 4 , wherein the piston compressor (24) is of the type of a sleeve compressor (58) or a piston ring compressor (45), and wherein the starting rotation frequency (114) is predetermined as a speed (109) at which a relative pressure (111) in a cylinder (42) of a piston-cylinder arrangement (36) of the piston compressor (24) remains at least 1% and a maximum of 5% to 20% of the operating compression power (104) during at least one full revolution (61) of the piston compressor motor (26). Compressor control method (100) according to one of the preceding claims, wherein - the power parameter (122) corresponds to a current (124) consumed by the piston compressor motor (26), the power parameter curve (130) corresponds to a current curve (132) of the consumed current (124) and the power parameter characteristic (140) corresponds to a maximum or minimum value (142, 144) of the current (124) in the current curve (132) or a characteristic (147) in the current curve (132) in the range of the maximum or minimum value (142, 144) of the current (124) in the current curve (132), or - the power parameter (122) corresponds to a voltage drop (126) across the piston compressor motor (26), the power parameter curve (130) corresponds to a voltage curve (134) of the consumed voltage (126) and the power parameter characteristic (140) corresponds to a minimum or maximum value (142, 144) of the voltage (126) in the voltage curve (134) or a characteristic (147) in the range of the minimum or maximum value (142, 144) of the voltage (126). Compressor control method (100) according to one of the Claims 1 until 6 , wherein the performance parameter (122) corresponds to a relative pressure (129) generated by the piston-cylinder arrangement (36) the performance parameter curve (130) corresponds to a pressure curve (136) of the generated relative pressure (129) and the performance parameter characteristic (140) corresponds to a maximum, minimum or constant relative pressure (129) in the pressure curve (136) or a characteristic (147) in the pressure curve (136) in the range of the maximum, minimum or constant relative pressure (129). Compressor control method (100) according to Claim 7 or 8th , wherein the performance parameter characteristic (140) corresponds to a characteristic (147) with a predefined slope (146) of the performance parameter curve (130). Compressor control method (100) according to one of the Claims 7 until 9 , wherein the piston (34) of the piston-cylinder arrangement (36) of the piston compressor (24) has a first position (56), in particular a bottom dead center (54), at which the volume (44) in a cylinder (42) of the piston-cylinder arrangement (36) of the piston compressor (24) corresponds to a maximum, and a second position (60), in particular a top dead center (62), at which the volume (44) in the cylinder (42) of the piston-cylinder arrangement (36) of the piston compressor (24) corresponds to a minimum, and the performance parameter characteristic (140) corresponds to the position (56, 60) of the piston (34) at which the compressor motor (26) has a predetermined angle of rotation (162), preferably in the range of 5° to 0° before reaching or substantially upon reaching the second position (60). Compressor control method (100) according to one of the preceding claims, wherein in step e) the continued operation of the piston compressor motor (26) with an operating rotation frequency (174) in an operating phase (171) or the stopping of the piston compressor motor (26) and re-operation of the piston compressor motor (26) with the operating rotation frequency (174) in the operating phase (171) after stopping after the recognition of the performance parameter characteristic (130) takes place by waiting after the time (156) of the recognition of the performance parameter characteristic (130) - a predefined period of time (170), which is in particular dependent on the starting rotation frequency (114), after which the continued operation of the piston compressor motor (26) with an operating rotation frequency (174) in an operating phase (171) or the stopping of the piston compressor motor (26) and re-operation of the piston compressor motor (26) with the operating rotation frequency (174) in the operating phase (171) after stopping or - the piston compressor motor (26) is further rotated for a predefined angle of rotation (162), after which the continued operation of the piston compressor motor (26) with an operating rotation frequency (174) in an operating phase (171) or the stopping of the piston compressor motor (26) and re-operation of the piston compressor motor (26) with the operating rotation frequency (174) in the operating phase (171) after stopping. Compressor control (28) for controlling a piston compressor motor (26), wherein the compressor control (28) is arranged to implement a compressor control method (100) according to one of the Claims 1 until 11 to execute. Compressor system (10) with a piston compressor motor (26) and a compressor control (28) according to Claim 12 , wherein the piston compressor motor (26) is preferably a brushless DC motor (30) or a controlled DC motor (32). Compressor system (10) according to Claim 13 , wherein the compressor system (10) is a braking system (12) or an air suspension system (14) for a vehicle (16), and the piston compressor (24) is arranged to provide compressed air (22) for a compressed air reservoir (18) of the compressor system (10). Vehicle (16) with a compressor control (28) according to Claim 12 or a compressor system (10) according to Claim 13 or 14 , which is preferably arranged to implement a compressor control method (100) according to one of the Claims 1 until 11 to execute.

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