DE10138998A1 - Device for controlling shift process for load switchable gearbox controls couplings with which gearbox input shaft speed can be adjusted superimposed on output shaft torque adjustment - Google Patents

Abstract

The control device (127) controls at least two couplings with which a revolution rate of the gearbox (114) input shaft (113) can be adjusted. The device can adjust the torque of the gearbox output shaft (118). The adjustment of the input shaft revolution rate is superimposed on the adjustment of the output shaft torque. AN Independent claim is also included for the following: a method of controlling a shift process for a load switchable gearbox.

Description

The invention relates to a device for controlling a Schaltablaufs in a power shift transmission according to the The preamble of claim 1 and a method of controlling a shift sequence in a power shift transmission after the sibling claim 8.

In DE 195 11 996 C1 is a method for controlling a Gear shift of a powershift transmission one Motor vehicle in the form of an automatic stepped transmission described. In a speed adjustment phase of the gearshift is the transmission input speed from the output speed in old gear to the target speed in the new gear accordingly regulated a desired course. The regulation takes place by means of a Control of two clutches whose Torque transmission capability is changeable.

The object of the invention is in contrast a device and a method for controlling a switching operation in a to propose power shift transmission, which is a special allow comfortable operation of the transmission.

According to the invention the object is achieved by the features of Claim 1 and the method of the independent claim 8 solved.

The device according to the invention is characterized in that by means of the device, a speed of a Transmission input shaft and a torque at a transmission output shaft are adjustable. The adjustment is done by means of a Control for changing a transmission capability of a disconnecting and a gearshifting clutch of the transmission. Couplings are in this context both Clutches which connect two shafts rotatably together can, as well as brakes, which are rotating components can non-positively connect with a transmission housing, Roger that. The couplings can, for example hydraulically or be electromagnetically actuated.

When switching from an original gear to a target gear must the speed of the transmission input shaft to a the Target gear corresponding speed can be brought. By means of Adjustment by the device according to the invention can continuous course achieved without jumps in the speed become. This is a prerequisite for a comfortable Circuit.

When switching, the transmission ratio changes. At one, for the duration of the circuit as constant assumed, output torque of the prime mover This results in a change in torque at the Transmission output shaft. At a setting of the speed of the Transmission input shaft is the torque at the Transmission output shaft not taken into account. It would be at one Circuit to strong, sudden changes in torque come. This would trigger a noticeable jerk or a Stimulate vibration of the drive train. This would be especially true an elastic drive train with small inertial masses problematic after the transmission.

The inventive adjustment of the torque on the Transmission output shaft can target the torque so be set so that no jerk or vibration is stimulated. This allows a particularly comfortable Operation of the gearbox. With the device according to the invention can provide comfortable shifting with minimal slip times the switching and disconnecting clutch can be achieved. This will cause a thermal overload and thus a Impairment of the life of the couplings avoided.

The inventive method according to the sibling Claim 8 is characterized in that in a first phase a torque of the transmission output shaft to a first Torque target value is set. In a second phase is the speed of the transmission input shaft to a Speed target value and at the same time the torque of Transmission output shaft to a second torque target value set.

With the first phase, the so-called overlapping phase the circuit sequence begins; the phase ends with the disconnecting clutch can no longer transmit torque. By means of the method according to the invention, the disconnecting and the engaging clutch of the transmission be controlled during the first phase so that the resulting characteristic of a known freewheel equivalent. This ensures that the shutdown Clutch only at the end of the overlap phase of one adhering to a sliding state. In the second Phase, the so-called Überhöhungsphase is the speed of the Transmission input shaft continuously and monotonously on the Target gear corresponding speed brought. At the same time that will Torque at the transmission output shaft to the target level of Follower set. This setting is also made continuously, so that no torque jumps occur. The Overcranking phase is completed when the switch-on Clutch transfers the entire torque in the adhesive state. The inventive method thus provides continuous Gradients of the speed of the transmission input shaft and the Torque of the transmission output shaft safe. this makes possible a particularly convenient sequence of the circuit.

Unteranspruch 2 shows in an embodiment of the invention a Device in which the adjustment of the speed of Transmission input shaft of the adjustment of the torque Transmission output shaft is superimposed. This forms the Setting the torque an internal control loop and / or an internal control and the setting of the speed one outer loop and / or an external control. Output variables of the speed setting are thus Input variables of the torque setting. This construction allows a particularly accurate and fast adjustment of the desired speed and torque values and thus allows particularly comfortable and fast gear changes.

Unteranspruch 3 shows an embodiment of the invention a Device by means of which a torque at the Transmission input shaft can be influenced. The torque can both increased and decreased. This is the Device, for example, in signal communication with a Control device of the prime mover and can be a Change of the output torque of the prime mover Request. This request is then made by the Implemented control device of the drive machine. The implementation can for example, by changing a Throttle position, an injection quantity, an ignition angle and / or an injection time take place. One more way for influencing is that the device For example, in signal communication with a Control device one between the prime mover and the transmission arranged electric machine stands, which in one Motor and can be operated in a generator mode. The electric machine can thus increase the torque at the Both increase and decrease the transmission input shaft. A Request for torque change of the invention Device is then controlled by the controller implemented electrical machine.

This is to adjust the speed of the Transmission input shaft and the torque at the transmission output shaft a additional manipulated variable available. The settings can to be done even faster and more accurately, which too particularly fast and comfortable gear changes.

Unteranspruch 4 shows in an embodiment of the invention a Device in which the adjustment of the speed of Transmission input shaft by means of a speed controller. The speed of the transmission input shaft is detected and the Device supplied. This detected speed is also for other functions of the device, such as a Control or regulation of a torque converter lockup clutch necessary. This speed can thus with a current Target speed compared and corresponding from the result Manipulated variables are calculated. The controller can, for example be implemented as a PI controller or a Riccati controller. By means of the control, the speed of the Set transmission input shaft particularly fast and accurately.

Subclaim 5 shows in an embodiment of the invention a Device in which the adjustment of the torque of the Transmission output shaft is done by means of a torque controller. For example, the controller may be implemented as an I-controller his. The size of the torque required for a control can by means of a suitable Torque detecting element detected and supplied to the device. This is a very accurate and fast determination of the size of the Torque possible. Another way to determine the size of the torque is for example in the Estimating the size by means of an observer, for example by means of a Kalman filter. In this case, the installation is a detection element not necessary, resulting in a Cost savings and a reduction of Failure probability of the device leads. By means of the scheme the torque on the transmission output shaft can be particularly set quickly and accurately. If both the speed as well the torque can be controlled, so does the combination of Both controllers are a so-called cascade control.

Subclaim 7 shows in an embodiment of the invention a Device in which parameters of the torque controller to changeable at a defined time during the switching process are. At the transition of the disconnecting clutch from the adhesive in the sliding state changes the physical structure of the gearbox and thus the structure of the controlled system. In order to this structural change does not lead to deviations of the torque leads from the setpoint, the controller parameters are on the occurrence changed the structure change. This will be a good one Correspondence of the actual values with the nominal values of the torque Ensured on the transmission output shaft and the circuit runs off comfortably.

Other advantages of the invention will become apparent from other features of Subclaims, the description and the drawings. Embodiments of the invention are in the drawings simplified and in the following description explained in more detail. Show it:

Fig. 1 is a schematic representation of a drive train of a motor vehicle and a device for controlling a shift sequence with a control of the torque of a transmission output shaft.

Fig. 2 is a schematic representation of a drive train of a motor vehicle with an electric machine between the engine and transmission and a device for controlling a shift sequence with a control of the torque of a transmission output shaft.

Fig. 3 is a diagram for timing of rotational speeds and torques in a pull upshift.

Referring to FIG. 1, a drive train 10 via a driving machine 11, which is designed as a combustion engine. The prime mover 11 is connected by means of a hydraulic torque converter 12 to a transmission input shaft 13 of a power-shiftable transmission 14 . The torque converter 12 serves as a starting element. The transmission 14 is designed as a planetary automatic transmission. At the transmission input shaft 13 , a speed sensor 15 is arranged, by means of which a rotational speed of the transmission input shaft 13 is detected. The transmission 14 is shown very schematically and has two gears 16 and 17 which are connected to a transmission output shaft 18 and via two clutches 19 and 20 are alternatively inserted. The clutches 19 , 20 are each operable with a hydraulic actuating device 21 , 22 . From the transmission output shaft 18 , a rotational speed and a torque is transmitted by means of a drive shaft 23 to an axle gear 24 , which transmits the torque in the same manner or different proportions via two output shafts 25 to drive wheels 26 in a conventional manner.

A device for controlling a switching sequence of the transmission 14 in the form of a control device 27 has a setpoint generator 28 which generates a desired value for the rotational speed of the transmission input shaft 13 . The setpoint generator 28 is in signal communication with a comparison element 29 , which is additionally in signal communication with the speed sensor 15 . The comparison element 29 generates a difference between the desired value and the measured rotational speed of the transmission input shaft 13 . This difference is fed to a speed controller 30 . By means of a signal line 31 , the speed controller 30 receives additional information about the state of the engine 11 and the transmission 14 , such as a shift request, a speed and a torque output of the engine 11 and a speed of the transmission output shaft 18th Based on this information, the speed controller 30 generates transmittable torque setpoints of the clutches 19 and 20 and a change in the output torque of the engine 11 . These setpoints are supplied by means of a signal line 32 to a torque controller 33 . The torque control 33 is additionally in signal communication with a setpoint generator 34 which generates a setpoint value for the torque at the transmission output shaft 18 . In addition, the torque controller 33 receives additional information about the state of the engine 11 or of the transmission 14 by means of a signal line 35 . Based on all the information supplied, the torque controller 33 generates set values for operating pressures of the clutches 19 and 20 , which are supplied to the actuators 21 and 22 via signal lines 36 and 37 . The actuators 21 and 22 convert the setpoints into drive pressures. In addition, a torque change request is generated, which is supplied to a control device 39 of the drive machine 11 by means of a signal line 38 . The control device 39 is in signal communication with measuring and adjusting elements, not shown, of the engine 11 and sets the torque change request of the torque control 33 to. The control device 39 is also in signal communication with the control device 27 of the transmission and transmits these measured or calculated variables of the drive machine 11 , such as, for example, the rotational speed or the output torque of the drive machine 11 .

A drive train 110 shown in FIG. 2 additionally has an electric machine in the form of a starter-generator 140 , which is arranged between a drive machine 111 and a torque converter 112 , in relation to the drive train 10 in FIG . The starter-generator 140 can be driven in a first mode by means of the engine 111 and charge a battery, not shown, of the motor vehicle. This reduces the torque on a transmission input shaft 113 . In a second mode of operation, the starter-generator 140 may be operated as an electric motor and may thus increase the torque on the transmission input shaft 113 . The necessary energy supplies the battery, not shown. The control is effected by a control device 141 which is in signal connection with the starter-generator 140 .

The transmission 114 has over the transmission 14 in Fig. 1 via an additional torque detecting element in the form of a torque sensor 142 , which is arranged on a transmission output shaft 118 .

The control device 127 has, compared with the control device 27 in FIG. 1, a torque controller 133 instead of a torque controller 33 . In addition, the controller 127 has a setpoint generator 134 which generates a set point for the torque on the transmission output shaft 118 , and a comparison element 143 which is in signal communication with the setpoint generator 134 and the torque sensor 142 . The comparison element 143 calculates the difference between the target value and the measured value of the torque on the transmission output shaft 118 and supplies it to the torque controller 133 . The torque controller 133 otherwise has the same inputs as the torque controller 33 in FIG. 1. Based on all the information supplied, the torque controller 133 generates set values for operating pressures of the clutches 119 , 120 and a torque change request which is transmitted via a signal line 144 to the controller 141 of the starter. Generators 140 is supplied. The control device 141 implements this requirement by means of a suitable control of the starter-generator 140 . The control device 141 is in signal connection with the control device 127 by means of a signal line 145 and sends state variables of the starter-generator 140, such as the added or removed torque, to the control device 127 .

FIG. 3 shows a diagram for the time representation of rotational speeds and torques in a pull upshift with the control device 27 according to FIG. 1 from an original gear into a target gear. The translation of the transmission 14 thus decreases in the circuit. In the diagram, three axboxes 50 a, 50 b and 50 c are shown. On the abscissa 51 a, 51 b and 51 c, the time is plotted. On the ordinate 52 a speeds are plotted on the ordinates 52 b and 52 c torques. The course of a circuit with a device according to the invention or with a method according to the invention is shown using the example of the upshift. However, the device and the method are applicable to all types of shift (Zughoch-, Schubhoch-, Zugrück-, push downshift).

In the axbox 50 a is the solid line 53, the rotational speed of the transmission input shaft 13 , as a dashed line 54, the speed of the transmission output shaft 18 is shown.

In the axbox 50 b as a solid line 55, the torque at the engaging clutch 19 , as a dashed line 56, the torque at the disconnecting clutch 20 and a dash-dotted line 57, the transmittable torque of the engaging clutch 19 is shown.

In the axbox 50 c is shown as a solid line 58 requested by the torque control 33 torque reduction, as dashed line 59, the output torque of the engine 11 and dash-dotted line 60, the torque on the transmission output shaft 18 .

All courses are only qualitative and greatly simplified shown.

In section a, the state before the circuit is shown. The engine 11 outputs a constant torque, which is completely transmitted from the disconnecting clutch 20 . This results in a constant torque at the transmission output shaft 18th Due to the torque accelerates the motor vehicle, which is expressed by the increasing speed of the transmission output shaft 18 . Since the original gear is engaged, the rotational speed of the transmission input shaft 13 increases in proportion to the rotational speed of the transmission output shaft 18 .

At the beginning of section b begins the upshift. The torque at the transmission output shaft 18 is adjusted by the torque controller 33 to a target value 61 at the end of the section b. For this purpose, the transmittable torque is reduced at the disconnecting clutch 20 , wherein the clutch 20 still adheres. The transmittable torque on the engaging clutch 19 is increased. The torque at the clutch 19 is identical to the transmittable torque in sections b and c. The output torque of the engine 11 remains unchanged unchanged. The speed of the transmission output shaft 18 increases more slowly than in section a. Since the clutch 20 still adheres, so the original gear is still switched, the speed of the transmission input shaft 13 also increases more slowly. The torque at the engaging clutch 19 becomes greater at the end of the portion b than the torque at the disengaging clutch 20 at the beginning of the portion b. The difference is called a so-called Überhöhungsmoment. This ensures that the disconnecting clutch 20 at the end of the section b passes from the adhesive to the sliding state. Thus, at the end of section b, a structural change of the tax route takes place. The section b is called a so-called overlap phase.

In section c, the speed of the transmission input shaft 13 is adjusted to the speed in the target gear. At the same time, the torque on the transmission output shaft 18 is adjusted to the level in the target gear. The section c is referred to as a so-called Überhöhungsphase. Since the disconnecting clutch 20 now slips, the transmission input shaft 13 is delayed due to the Überhöhungsmoments; the speed of the transmission input shaft 13 decreases. To assist this and to enable a better adjustment of the torque at the transmission output shaft 18 , the speed control 33 requests a torque reduction at the control device 39 of the drive machine 11 . This requirement is implemented and the output torque of the engine 11 decreases according to the requirement. In order to adjust the torque at the transmission output shaft 18 to the level of the target gear, the torque at the engaging clutch 19 is reduced again. The torque reaches in section b the value of the torque of the disconnecting clutch 20 in section a; this will reach the level of the target gear and the torque will then be kept at this level. Since there is also a torque on the transmission output shaft 18 in this section, the speed of the transmission output shaft 18 continues to increase, but not as much as in the section b. At the end of section c, the rotational speed of the transmission input shaft 13 has reached the speed of the target gear and the engaging clutch 19 is in the adhesive state. The target gear is engaged. At the end of section c, the transmittable torque of the clutch 19 is increased by a safety impact to safely prevent the clutch from slipping.

In section d, the target gear is engaged and the rotational speeds of the transmission input shaft 13 and the transmission output shaft 18 both increase. The output torque of the engine 11 is again at the level of sections a and b. The torque at the transmission output shaft 18 is also at a constant level, which, however, being an upshift, is smaller than in the original gear (section a). The torque at the clutch 19 is constant and as large as the torque at the clutch 20 in the section a. The transmittable torque of the clutch 19 is greater than the torque on the clutch 19 by the safety impact. The circuit is complete.

The gearbox can be equipped with a Double clutch be executed.

The electric machine can also be installed at another location be arranged and, for example by means of a belt Introduce torque in the drive train. The introduction can between the prime mover and the transmission, but also at the transmission side facing away from the drive machine done.

A change in the torque at the transmission input shaft can also common to the prime mover and the electric Machine be performed.

The described embodiments are only exemplary embodiments. A combination of described features for different embodiments is also possible.

Claims (8)

1. A device for controlling a shifting sequence in a power shiftable transmission ( 14 , 114 ) with at least two clutches ( 19 and 20 , 119 and 120 ) which can be activated by the device (control device 27 , 127 ), in a motor vehicle,
by means of which a speed of a transmission input shaft ( 13 , 113 ) is adjustable,
characterized in that
by means of the device (control device 27 , 127 ) a torque at a transmission output shaft ( 18 ) is adjustable. 2. Apparatus according to claim 1, characterized in that the adjustment of the rotational speed of the transmission input shaft ( 18 , 118 ) of the adjustment of the torque of the transmission output shaft ( 13 , 113 ) is superimposed. 3. Apparatus according to claim 1 or 2, characterized in that by means of the device (control means 27 , 127 ), a torque on the transmission input shaft ( 13 , 113 ) can be influenced. 4. Device according to one of claims 1 to 3, characterized in that the adjustment of the rotational speed of the transmission input shaft ( 13 ) by means of a speed controller ( 30 ). 5. Device according to one of claims 1 to 4, characterized in that the adjustment of the torque of the transmission output shaft ( 118 ) by means of a torque regulator ( 133 ). 6. Device according to one of claims 1 to 5, characterized in that the device (control means 127 ) is in signal communication with a torque detecting element ( 142 ) which detects the torque of the transmission output shaft ( 118 ). 7. Device according to one of claims 5 or 6, characterized in that parameters of the torque controller ( 133 ) can be changed at a defined time during the switching sequence. 8. A method for controlling a shift sequence in a power shift transmission ( 14 , 114 ) in which
in a first phase, a torque of a transmission output shaft ( 18 , 118 ) is set to a first torque target value, and
in a second phase, a speed of a transmission input shaft ( 13 , 113 ) is set to a speed target value and at the same time the torque of the transmission output shaft ( 18 , 118 ) to a second torque target value.