FI118975B - Control of the engine and propulsion transmission speed - Google Patents

Description

FIELD OF THE INVENTION The invention relates to a method for controlling a hydrostatic transmission of a machine and a primary power source. The present invention relates to a method for controlling a hydrostatic traction transmission of a work machine. The invention relates to a system for controlling a hydrostatic traction transmission and a primary power source of a work machine.

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Background of the Invention

According to the prior art, diesel-15 engine 1, the mechanical power of which is utilized, for example, in the transmission of the driving machine of a machine, is used as a power source for working machines and forest machines moving in the field. Diesel engine 1 acts as the primary source of power for the work machine, which may have other alternatives. Typically an internal combustion engine is used. The mechanical power obtained from the shaft 2 of the diesel engine 1 is proportional to the 20 torques and the rotational speed provided by the diesel engine 1. In the case of diesel engine 1, the controlled variable is the speed at which the diesel engine produces mechanical power and torque. Diesel Engine Operation • · ·: Based on a number of torque curves with torque dependent * "·: speed. The torque curves are automatically selected by the" t ": ECU. It is clear that the efficiency varies and: at high speeds, fuel consumption increases. Speed- · »«. · * ·. The control value given by the driver and the driving speed of the implement, typically provided by the pedal 3. The pedal generates a signal 5 (ref), which is dependent on the position of the pedal 3, and supplied to the control system 6. By means of the -..... 4, other ways can be used to provide the control value - **: · *. Typically, the larger the pedal-

The higher the speed and the travel speed is achieved, the position or the control value or the change in the position is.

* • · • · 35 The diesel engine delivers the power it needs at any given moment, such as moving the machine and driving it in different situations and terrain 2 118975. It is clear that driving on a flat surface and on difficult terrain requires different traction control.

Figure 2 illustrates the operation of the control in a normal situation where the speed 21 (vertical axis, in rpm) of the diesel engine is linearly dependent on the control value (ref), i.e. the position of the pedal. The horizontal axis represents the position of the pedal between the neutral position and the maximum position, i.e., maximum movement. The horizontal axis thus represents the value of the control value given by the driver, which is scaled from 0 to 1 in the figure. The same figure also shows the machine speed 22 (vertical axis, in rpm), which in this case is depicted by the drive 7 engine speed. The engine has a maximum speed of 24 and the machine has a maximum speed of 23.

15 The use of a diesel engine significantly influences the fuel economy of the machine and the noise level experienced by the driver. Machines typically have an inching function which limits the maximum working speed of the machine. The gear is necessary, for example, when traveling on difficult terrain, where slower and more demanding driving is required, where a change in pedal position does not imply a major change in travel speed. The speed behavior of the diesel engine is not really affected by the gearbox, but solely by the operation of the hydro lX · static transaxle, since the traction pump *: **: revolution volume is greatly limited.

25 The reduced flow rate of the motor guides the machine to slow running.

: Maximum pedal position means slower travel speed but die. · * ·. the selector motor has a maximum speed (2200 rpm). Figure 4 illustrates the operation of the gear in question, noting that the curve (engine speed) for travel speed t v> has been significantly reduced and *: V 30 is now about 0 to max 400 rpm. The maximum speed 43 is reduced • * * ·; · but the maximum 44 speed is not changed.

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In the prior art, in the implement control system, the deceleration gear is a user selectable mode involving either a fixed 35 or an adjustable parameter. In the example of Figure 4, the parameter has to be set to, for example, 10% (or 0.1), so that the maximum speed 43 in slow mode is about one-tenth of the maximum speed 23 of the normal 11897575. This adjustability allows a variety of slower and faster gears 0-100%. For normal driving, the control system is defined as an equivalence or dependence between the control value and the speed.

5 The control system requests the desired engine speed from the diesel engine via the control unit. The steering system is defined as the maximum and minimum speeds that can be used. The torque curves are automatically selected by the ECU unit, but the maximum RPM is controlled by a parameter. In normal driving, the maximum position of the pe-10 daal (maximum control value) is typically matched by a certain maximum speed and rotation speed.

The problem with slow driving, however, is that the deceleration gear will continue to be used when moving into terrain or on a road that is clearly easy to drive and that the speed could be increased. However, this situation results in the pedal being moved to its maximum position and, at the same time, a significant increase in diesel engine RPM. However, it is not necessary to increase the speed because the power requirement has not increased. As a result, with high rpm, the fuel economy of the machine 20 is reduced and noise levels increase.

··· v: Summary of the Invention ··· The purpose of the invention is to eliminate the above problems, to improve the fuel economy of the machine and to reduce unnecessary noise and, at the same time, vibration affecting the driver. With the invention, the die ···. and high engine speeds can be avoided, reducing fuel consumption while improving component durability and reducing maintenance.

The method according to the invention for controlling the hydrostatic traction transmission and the primary power source of a working machine is disclosed in claim 1. The method of the invention in controlling the hydrostatic traction transmission of a working machine is disclosed in the patent claim 35. 13. The system of the invention for controlling the hydrostatic traction transmission and primary power source of a working machine is disclosed in claims 18 and 19.

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The principle of the invention is to limit the maximum speed of the diesel engine while limiting the maximum working speed of the implement. As a result, at the maximum position set by the pedal or other corresponding driver, a revolution is achieved that is less than 5 revs above the previous maximum revolution that was used during normal driving.

A further principle of the invention is to utilize the parameter used in selecting the slow drive also for controlling the primary power source. The Mo-10 lemmas, both maximum speed and maximum speed of the diesel engine, now depend on the value of one of the above parameters. Typically, the aforementioned speeds are substantially linearly dependent on the position of the pedal, a signal representing the position of the pedal, or other control value provided by the driver, which may be given, for example, by changing the position of the 15 joysticks.

With the invention, the desired driving speed is achieved at a lower speed, provided that the power requirement is not increased and no higher speed is required.

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The invention also utilizes the extended normal mode of operation, whereby the maximum speed of the diesel engine is not affected, i.e., it is not * · · restricted, and the maximum speed, i.e., is not limited, by limiting the pump flow rate. Instead, the behavior of the pedal is influenced so that the desired travel speed is achieved by a lower movement of the pedal, i.e., the offset of the pedal from the neutral position is smaller than during the normal driving mode. The same applies to; ***: change of control value.

λ m m . ·. 30 Extended mode shown, which can also be called high-speed mode ···. mode, is especially useful when driving a machine, for example, · ·: * Load machine on flat surfaces when power is not high, ie.

: V when driving on roads or other flat surfaces. It is typical of the invention that the desired travel speed is achieved with a lower pedal: ·! 35 movements compared to the previous one. The travel speed is no longer linearly dependent on the position of the pedal, although the maximum pedal position ***** still achieves maximum rev and maximum travel speeds.

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The high-speed mode can also be used alone, controlled by its own parameter that can be set and entered by the driver into the control system. A particular advantage is obtained when it is used to complement the drive transmission operation in combination with a slow drive which limits the maximum engine speed of the diesel engine.

The high-speed mode utilizes a fixed or adjustable parameter that affects the transmission's performance. High speed mode is enabled when slow mode is off, ie its parameter is set to 100% (or 1.0). The machine control system automatically takes care of the change of modes, depending on the value that the user and the machine operator select for the parameter and input it into the control system.

The principle of the invention is, moreover, to utilize the parameter used in selecting the slow-speed mode for controlling the diesel engine as well as for controlling the traction transmission so that the same parameter also determines the use of the 20-speed mode mentioned above. The maximum speed and maximum speed of the diesel engine, as well as the speed of the pedal, now depend on the value of one of the parameters to be set. An example is a parameter that is adjustable between 0% and 200% or between - ··: 100% and + 100%, or by using any other suitable minimum and maximum ** · **: 25 values. In the example shown, the range 0% to 99% is reserved for slow driving, 100% is reserved for normal driving, and 101% to 200% is reserved for fast driving.

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DESCRIPTION OF THE DRAWINGS 30 * · · ::: The invention will now be described in more detail by way of example and with reference to the accompanying drawings, in which: Figure 1 shows the components and basic features of the system according to the invention. Figures 2 and 3 illustrate prior art operation during normal driving, Figures 4 and 5 illustrate prior art operation during slow travel 5, Figures 6 and 7 illustrate the control components of the system of the invention, 10 figures 8 and 9 illustrate the operation of the invention during slow driving, Figures 10 and 11 illustrate the operation of the invention during fast driving, and

DETAILED DESCRIPTION OF THE INVENTION As illustrated in Figure 1, forestry machines typically use a hydrostatic drive transmission 7 which converts the mechanical power provided by the diesel engine 1 into hydraulic power at pump 8, whereby power is v? Pump 8: is generally adjustable, allowing volume flow to be varied. Hydraulic power is utilized in the engine 9, which in turn provides the output shaft with torque and rotation speed. Engine 9: The speed depends on the volume flow and the setting of the engine 9.

; ***: The motor 9, in turn, is coupled to gear 10, by means of which * ·· mechanical power is transmitted to the wheels of the machine, e.g. . ·. 30 by means of the coupling 11 and the differential shafts 12 to the bogies 13 having • · · the wheels of the implement mounted on the rotating hubs. The Hydro - **: * 'static traction transmission 7 is controlled by the electronic control system V of the implement, and the diesel engine 1 can be controlled by an electronic control unit 14 (ECU).

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Figure 1 shows a solution for a closed circuit and a 1-silicon - ** "* system, in particular a 1-motor system.

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7 Transmission provides infinitely variable machine travel speed as pump and motor are infinitely variable. In addition, even at low engine speeds, high wheel traction is available.

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The pump 8 is, for example, an inclined-plate type axial piston pump, which is adjustable in rotation volume (Vg), in which the direction of the volume flow and, at the same time, the driving direction of the implement can be reversed by rotating the pump Thus, the controllable mouth-10 Reina is the pump revolution volume, and thus the volume flow it produces. The motor is, for example, an axial piston engine of the type oblique plate or oblique shaft, or a radial piston engine, which may also have a fixed volume, in which case the motor is not adjustable. The controllable quantities are thus the engine speed (Vg) and the rotation speed.

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Known control systems have been used to control forest machines. The control system monitors eg. forestry machine diesel engine, hydrostatic drive transmission, and all related ancillary functions. The control system in question operates, for example, in a PC environment. The Oh-20 sensing system display and central unit are located in the driver's cab. The control system's control automation is based on the state-of-the-art CAN bus solution in the control bus • • ♦, where data is transmitted digitally.

Figure 6 illustrates in more detail what are the control system accessories C *: which are placed in the implement cab near the driver.

The control system accessories include a display module 62, a PC key "*: a keyboard 63, a touchpad mouse 64, a central processing unit (HPC-CPU) with processors and memory 65, and a printer 66, a hub module and a seat. ·. 30 The control values of the method according to the invention and are shown graphically to the user using the display module 62. The equipment also includes one or more control panels 71 shown in Fig. 7, whose control keys, buttons and joystick control the control system! .

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The application required to implement the invention and the software contained therein are installed in a central control unit of the control system having the required RAM and mass memory. Application installation is performed either on a new forest machine or as a retrofit on an older forest machine, where the application transfer medium is, for example, a CD-ROM. For example, the display module has the required CD drive. The Oh-5 sensing system utilizes a well-known operating system under which the application is run.

The Execution Environment may be various computers and operating systems, in particular forest machine processor-based control systems for running applications and software serving the control system, in particular personal computers (PCs) installed on the forest machine. ), or a workstation operating as such, which includes a suitable operating system. The hardware and operating system have the necessary applications and protocol tools to communicate with other devices.

The digital control and measurement system of the forest machine and especially the harvester is based on CAN bus technology (Controller Area 20 Network) and distributed control. The system consists of independent intelligent modules, which communicate via CAN bus. The system controls the diesel engine, hydrostatic drive transmission, • · · *:!. * Boom system and harvester head, and associated auxiliary functions. The system typically consists of six or seven modules that are on the CAN bus and are illustrated in more detail in Figure 7. The system modules include e.g. display module HPC-D, computer-s.iji central processing unit HPC-CPU (Harvester PC - Computer Processor

Unit), a Hub module, to which other modules are directly connected, except for the display unit and harvester head module. 30 The control module and control panels 71. for the system control are connected to the chair module Ch (s). accelerator pedal or pedal pressed by driver on machine ·· · ϊ \! while driving to change the driving speed. The pedal is fitted with the necessary sensor, for example an adjusting resistor, which is provided by the control system: · *. 35, which depends on the position of the pedal. The position of the pedal * «· can be varied between free position and maximum movement '· * ·' steplessly. The transmission module Tr (Transmission module) manages the control and communication of the diesel engine, transaxle, and associated auxiliary functions of the 118975 9 base engine. The transmission module, i.e., controls the revolutions of the above pump and motor. The ECU (Engine Control Unit) is an engine control unit that controls and monitors engine functions.

5 The diesel engine provides speed and, on the other hand, the control system can supply a signal to the control unit (ECU) that describes the desired engine speed. The load system has a more modular system compared to a harvester.

As shown in Figure 2, the traction transmission control is usually carried out such that the maximum pedaling speed 23 is reached at the maximum pedal position, linearly with respect to the pedal position, with the pedal in neutral position at zero speed. Figure 3 illustrates the behavior of the pump (curve 31) and motor (curve 32) revolutions of the pedal (horizontal axis) in the respective positions 2. In Figure 2, the diesel engine speed begins to increase from 800 rpm and the running speed is depicted as the engine speed (0 to max 4300 rpm). Similarly, the diesel engine speed changes, but starting at a certain minimum speed. The RPM can be set to a certain minimum level below which it must not be lowered, so the RPM may begin to increase at a later stage only when the pedal is depressed sufficiently. The minimum level is set, for example, when higher speeds and power are required for other functions of the forestry machine. The pump and motor control are more precisely *! ··: 25 implemented with the motor at maximum revolutions and: [**: the pump revolutions are increased when the pedal is pressed. When:; *: the pedal is pressed further, the pump revolutions finally reaches. * · *. maximum, at which point the engine speed is reduced. This achieves the desired travel speed at each pedal position.

: 30 IV.m Figure 4, on the other hand, illustrates a situation where a slow gear **, · * is used, ie slow travel. It is noted that the engine speed j * V (running speed 42) is limited by the fact that the volume flow rate of the pump in relation to the pedal position is limited compared to the 35 normal situations shown in Figure 2. The diesel engine speed (curve 41) will remain at normal driving speed. Figure 5 shows that the pump (curve • · ··· 10

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51) does not reach its maximum RPM at all and the engine position does not change (curve 52).

Figure 8 illustrates a situation in which, in addition to slow running, limiting the maximum speed 84 of the die-5 selector motor based on a common adjustable parameter set to 10%. It is noted that the speed of the diesel engine (curve 81) is linearly dependent on the position of the pedal, but at maximum pedal position, the speed is limited to 1280 rpm, whereas in Figures 2 and 4 it was 2040 10 rpm. The driving speed (curve 82) has the maximum value corresponding to Figure 4. The revolution volume of the Moot-15 market does not change (curve 92).

Fig. 10 illustrates a situation in which the high speed mode is used, based on an adjustable parameter which may be common to the slow mode and the normal mode. The parameter value is set to 200% (on a scale of 0% to 200%). Figure 10 also plots the running speed behavior (curve 104) for comparison.

It will be noted that in the high-speed mode (curve 101), e.g., 2000: £: rpm is achieved at the pedal position of about 0.23 (23%), while normally v: (curve 104) is achieved only at the pedal position of about 0.47 ( 47%). The major difference in the pedal positions is about 2750 rpm, due to the linear speed behavior of two different consecutive cycles, but including a discontinuity 105 at about 2750 rpm. However, the end point 106 and the start point of the travel speed curve 101 are the same as in normal mode, as shown in Figure 2. Die-, ·. At 30 RPM (curve 102), the same maximum value is 103 * «· y. T as during normal driving. Figure 11 shows the behavior of the transaxle *: ** as compared to Figure 3. The pump is driven to maximum RPM faster (curve 112), i.e., with a shorter pedal stroke, and in addition, the engine RPM is lowered faster (curve 35 111). Control as shown means that the engine reaches its minimum RPM earlier, resulting in the aforementioned discontinuous - '* · * starting point 105.

Figure 12 shows an example where the fast run parameter is set to 150% (on a scale of 0 to 200%). It will be appreciated that the fast-running discontinuous curve 121 begins to approach the drive-speed curve 124 that is used in normal mode. Figure 13 shows that the pump and motor are controlled at a later stage than in Figure 11, i.e. the movement of the pedal is longer. The maximum values 123 and 126 10 correspond to those shown in Fig. 10, and the rotation speed curve 122 is also the same. The discontinuity point 125 is reached later, with a longer pedal movement.

Referring to Figure 1, the invention is applied in that parameter (set) 15 is supplied to control system 6, which in turn controls the engine control unit 14 (ECU) by providing it with a signal corresponding to the requested RPM. presentation on the display module screen controlled by the pointer. It can also be a percentage or other ratio or value that is entered for control, for example by means of a keyboard. The requested rotation speed, in turn, is proportional to the position of the pedal 3 in a ratio or dependence determined by the value of the pa-ν 'parameter. The pedal position signal 5 is obtained from the sensor 3 following the pedal 3V position. Instead of the pedal 3, another "* ·: 25 corresponding behavioral control value (ref) could be used. The control system: ***: knows the maximum rotational speed from diesel engine 1 and:: *: The pump 8 and the motor 9 are controlled by the control system as described above, controlling the setting of their rotational volume. Kek -, ... 30 is well known in the art, *: · * components and parts which are modified in the manner required by the invention, however, modification and application will be apparent to one skilled in the art from the foregoing description.

! ** 35 * «| ..Γ The invention is not limited to the examples above, but * ··· 'may vary within the scope of the appended claims.

Claims (19)

A method of controlling the hydrostatic propulsion transmission and the primary source of power of a working vehicle, in which method: 5. controlling the function of the hydrostatic propulsion transmission in a state of slow driving, such that the driving speed is proportional to a control value given by the driver but lower than the driving speed in a state of normal driving, corresponding to the same said control value, characterized in that: - it is further limited the speed of the primary power source in said state for slow driving so that the speed of rotation is still proportional to the control value given by the driver but lower than the lap speed in the state of normal driving, which corresponds to the same said control value. The method according to claim 1, characterized in that: - the power is transmitted to the hydrostatic power transmission by means of the primary power source; 20. the hydrostatic power transmission is controlled in the state of normal driving so that the driving speed thus obtained is proportional to the the control value given by the driver, which can vary within the limits of predetermined limits, - you also control the speed of the primary power source under the condition of normal driving, so that the speed of rotation is pro * *; * portioned with that given by the driver. the control value, and the function of the hydrostatic driving force transfer: ···: the casing in the state of slow travel is said to say that the driving speed is still proportional to the control value given by the driver but lower than the driving speed in the state of normal driving,, /; - the lap speed of the primary power source is limited in the state of the slow run so that the lap speed is all- '** evenly proportional to the control value given by the driver but lower: Y: 35 than the lap speed in the state of normal driving. • · 118975 Method according to claim 2, characterized in that the proportionality between the rotational speed of the primary power source and the control value given by the driver is restored to correspond to the proportionality in the state of normal driving, and the function of the hydrostatic thrust transmission in the state of fast driving is controlled. , that the driving speed is proportional to the control value given by the driver but higher than the driving speed in the state of normal driving. Method according to claim 2, characterized in that the maximum permissible value of the revolving speed in the state of the slow run is less than the maximum permissible value of the rotational speed in the state of the normal run, and the maximum permissible value of the driving speed in the state of the slow run. is less than the maximum allowable value of the driving speed in the state of normal driving. Method according to Claim 3, characterized in that the maximum permissible value of the revolving speed in the state of the fast run is substantially the same as the maximum permissible value of the revolving speed in the state of the normal run and the maximum permissible value of the driving speed in the state. of fast driving is essentially: ··; ·; the same as the maximum permissible value of the driving speed in the state of normal driving. ... 25 Method according to claim 2 or 4, characterized in that the relationship between the control value and the driving speed and between the control value and the speed of rotation is essentially linear. ··· Process according to Claim 3 or 5, characterized in that The difference between the control value and the revolution speed is essentially linear. • · · • 9 • · • * ·. · *. Method according to Claim 3, 5 or 7, characterized in that the relationship between the control value and the running speed is essentially non-linear such that with small values of the control value the driving speed changes more quickly than V * 35 than with Large values of the control value. • · 118975 Method according to claim 8, characterized in that the relationship between the control value and the driving speed consists of two linear sections one after the other. Method according to claim 3, characterized in that the dependence of the driving speed and the speed of rotation on the control value is based on the value of a parameter used which is common to the state of normal driving, slow driving and fast driving. 10 Method according to Claim 1 or 2, characterized in that the dependence of the driving speed and the speed of rotation on the control value is based on the value of a parameter used which is common to the state of normal driving and the state of slow driving. 15 Method according to claim 10, characterized in that the parameter can be set by the user between a minimum value and a maximum value, between which a normal value for the state of the normal run is found. 20 A method of controlling hydrostatic thrust transmission of a working machine, in which method: T: - controlling the function of hydrostatic thrust transmission in a state of normal driving, such that the driving speed is proportional to a control value given by the driver; ··. Characterized in that: • ♦ - the function of the hydrostatic force transmission is controlled in a * :: f state of the fast driving so that the driving speed is still • · * ··· 'proportional to the control value given by the driver but higher than the driving speed in the state of normal driving, which corresponds to the same control value, and that the relationship between the control value and the driving speed in the state of fast driving is essential: nonlinear, that with small values of the control value the driving speed changes more rapidly than with Large values of control value. • · ··· ♦: .v 35 14. A method according to claim 13, characterized in that: *: **: - transmits power to the hydrostatic power transmission by means of the primary power source, 118975 - controls the hydrostatic power transmission in the state of normal driving so that the resulting driving speed is achieved. the speed is proportional to the control value given by the driver, which can vary within the limits of predetermined limits, and 5 - the speed of the primary power source is also controlled in the state of normal driving and the fast driving so that the speed of rotation is proportional to the control value given by the driver. 10 Method according to claim 14, characterized in that the maximum permissible value of the revolving speed in the state of the fast run is essentially the same as the maximum permissible value of the revolving speed in the state of the normal run and the maximum permissible value of the driving speed in the state of the fast run is essentially the same as the maximum allowable value of the run speed in the state of normal run. Method according to claim 13, 14 or 15, characterized in that said relation is based on the adjustable value of the parameter. Method according to Claim 13, characterized in that the relationship · * · ′: between the control value and the driving speed consists of two linear sections one after the other. · · ... 25 18. A system for controlling hydrostatic thrust transmission and a primary ***: 'power source of a working machine, which is arranged to: • · · - control the function of hydrostatic thrust transmission in a: state of slow running, say that the driving speed is proportional with a control value given by the driver but lower than the driving speed: 30 in a state of normal driving, which corresponds to the same said control value,. characterized in that the system is further arranged to: • · * - limit the lap speed of the primary power source in said '*; ** state of the slow run so that the lap speed is still sVs still proportional to the control value given by the driver but ·: · * : lower than the lap speed in the state of normal driving, which corresponds to the same said control value. 118975 19. A system for controlling hydrostatic thrust transmission and a primary source of power of a working machine, which is arranged to: - control the function of hydrostatic thrust transmission in the state of normal driving so that the driving speed is proportional to a control value given by the driver; characterized in that the system is further arranged to: - control the function of the hydrostatic power transmission in the state of the fast driving so that the driving speed is still proportional to the control value given by the driver but higher than driving the speed in the normal driving state; which corresponds to the same said control value, and that the relationship between the control value and the driving speed in the state of fast driving is essentially nonlinear, so that with small values of the control value the driving speed changes more rapidly than with large values of the control value. • · · · · · · · · ··· • 1 · • · · · 1 * «· • 1» · «·· • φ · • · · * ·· • · · • · f · • 1 1 • · «· ·« 1 · • 1 ·· «•« • · · 1 · • 1 * 1 1 1 · • 1 * «1 • · • · • · · • ·« · · · ««