JP2013124031A - Road surface gradient estimation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a road surface gradient estimation device capable of more precisely estimating a road surface gradient even in the middle of changing gear position.SOLUTION: In the road surface gradient estimation device which calculates output torque Tout output to the output shaft of an automatic transmission and estimates the road surface gradient θ on the basis of the reference acceleration αbase obtained on the basis of the calculated output torque Tout and an actual acceleration α, when the gear position is changed by such regripping that one side of two clutches is released and the other side is engaged, the output torque Tout is calculated by summing up transmission torque of a release side clutch calculated by multiplying torque capacity Trel of the release side clutch by a value obtained by dividing a gear ratio γbe before gear change by the torque sharing ratio Krel of the release side clutch, and transmission torque of the engagement side clutch calculated by multiplying torque capacity Tapp of a clutch of the engagement side by a value obtained by dividing a gear ratio γaf after the gear change by the torque sharing ratio Kapp of the engagement side clutch (S410 to S430).

Description

  The present invention includes a prime mover and a transmission capable of changing a gear position by changing a clutch that releases one of a plurality of engagement elements and engages the other, and transmits the power from the prime mover to the transmission. The present invention relates to a road surface gradient estimation device that is mounted on a vehicle that travels by being output via the vehicle, and that estimates the gradient of the road surface on which the vehicle is traveling.

  Conventionally, as this type of road surface gradient estimation device, a device that estimates a road surface gradient based on driving force of driving wheels and vehicle acceleration has been proposed (for example, see Patent Document 1). This device is provided with a rotation speed sensor (rotation speed sensor) that detects the rotation speed (rotation speed) of a turbine shaft that is an input shaft of the automatic transmission, and the driving force of the drive wheels is determined by turbine torque (input torque). Is calculated by multiplying the gear loss by the gear ratio, and the vehicle acceleration is calculated by dividing the current and previous turbine speed deviation by the current gear ratio of the automatic transmission when the vehicle acceleration is not being changed. The vehicle acceleration set last time is set during the shift or before the lapse of a predetermined time after the shift.

JP-A-10-153253

  In the above-described apparatus, the driving force to the driving wheel is calculated by multiplying the input torque of the transmission by the gear loss and the gear ratio, but the gear ratio used for the calculation during the shift is not mentioned. . By the way, in a type of transmission that changes the gear position by changing one of a plurality of engagement elements (clutch and brake) and engaging the other, the engagement element on the engagement side is changed from the engagement element on the release side to the engagement side. When there is a discrepancy between the calculated driving force and the actual driving force due to the transfer of torque transmission to the engagement element and the change in the rotational speed of the input shaft, resulting in fluctuations in the driving force to the drive wheels. In this case, it is difficult to accurately estimate the road surface gradient.

  The main object of the road surface gradient estimating apparatus of the present invention is to estimate the road surface gradient more accurately even while the gear position is being changed.

  The road surface gradient estimation apparatus of the present invention employs the following means in order to achieve the main object described above.

The road surface gradient estimation apparatus of the present invention is
A prime mover and a transmission capable of changing a gear position by changing one of a plurality of engaging elements and releasing the other, and outputting power from the prime mover via the transmission. A road surface gradient estimation device that is mounted on a vehicle that travels and estimates the gradient of the road surface on which the vehicle is traveling,
While the gear stage of the transmission is being changed, a disengagement-side transmission torque that is a torque transmitted by a disengagement-side engagement element and an engagement-side engagement element are transmitted among the plurality of engagement elements. And calculating the output torque output to the output shaft of the transmission using the calculation formula of the sum of the calculated disengagement side transmission torque and engagement side transmission torque. The gist of the invention is to estimate the gradient of the road surface based on the calculated output torque and the acceleration of the vehicle.

  In the road surface gradient estimation device according to the present invention, the engagement with the disengagement-side transmission torque, which is the torque transmitted by the disengagement-side engagement element among the plurality of engagement elements, while the transmission gear stage is being changed. The engagement side transmission torque, which is the torque transmitted by the engagement element on the mating side, is calculated and output to the output shaft of the transmission using the calculation formula of the sum of the calculated release side transmission torque and the engagement side transmission torque. The output torque is calculated, and the road surface gradient is estimated based on the calculated output torque and the acceleration of the vehicle. As a result, the output torque can be calculated more accurately than when the output torque is calculated by multiplying the input torque by the gear ratio of the transmission while changing the gear position. As a result, the road surface gradient can be estimated more accurately even while the gear position is being changed.

  In the road surface gradient estimation device of the present invention, the disengagement-side transmission torque is a ratio of a torque that is shared by the disengagement-side engagement element with respect to the input torque of the transmission with respect to the transmission gear before the gear shift. Divided by a certain sharing ratio and further multiplied by the torque capacity of the disengagement-side engagement element, the engagement-side transmission torque is obtained by changing the gear ratio at the gear stage after the shift to the input torque of the transmission. Alternatively, it may be calculated by dividing by the sharing ratio, which is the ratio of the torque shared by the engagement element on the engagement side, and further multiplying by the torque capacity of the engagement element on the engagement side. it can

  Further, in the road surface gradient estimation device of the present invention, while the rotational speed of the input shaft of the transmission is being changed to the rotational speed corresponding to the speed stage after the speed change, the inertial system on the front stage side of the input shaft. It is also possible to calculate the output torque by adding an inertia term for calculating the torque transmitted to the output shaft based on the change in rotation to the calculation formula. In this way, it is possible to more accurately estimate the road surface gradient regardless of the change in the rotation of the inertial system while changing the gear position.

It is a block diagram which shows the outline of a structure of the vehicle 10 carrying the road surface gradient estimation apparatus of this invention. FIG. 2 is a configuration diagram showing an outline of the configuration of a transmission mechanism 26. 4 is an explanatory diagram showing an example of an operation table of the speed change mechanism 26. FIG. FIG. 6 is a velocity diagram showing the relationship between the rotational speeds of the rotary elements of the speed change mechanism 26; 7 is a flowchart illustrating an example of a road surface gradient estimation processing routine executed by an ATECU 29. 4 is a flowchart showing an example of a non-shifting output torque calculation process executed by an ATECU 29. 7 is a flowchart illustrating an example of a first pattern shift output torque calculation process executed by an ATECU 29; 7 is a flowchart showing an example of second pattern shift output torque calculation processing executed by an ATECU 29; It is explanatory drawing which shows the mode of the time change of the input shaft rotational speed Nin at the time of the 1st pattern shift in an Example, oil_pressure | hydraulic instruction | command Papp, Prel, input torque Tin, and output torque Tout. It is explanatory drawing which shows the mode of the time change of the input shaft rotational speed Nin at the time of the 2nd pattern shift in an Example, oil_pressure | hydraulic instruction | command Papp, Prel, input torque Tin, and output torque Tout.

  Next, embodiments of the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of the vehicle 10 on which the automatic transmission 20 is mounted, FIG. 2 is a configuration diagram showing an outline of the configuration of the transmission mechanism 26, and FIG. 3 is an operation table of the transmission mechanism 26. It is explanatory drawing shown.

  As shown in FIG. 1, an automobile 10 according to the embodiment includes an engine 12 as an internal combustion engine that outputs power by explosion combustion of hydrocarbon fuel such as gasoline and light oil, and a crank angle from a crank angle sensor 15. It is connected to an engine electronic control unit (hereinafter referred to as an engine ECU) 16 for controlling the operation of the engine 12 by inputting data relating to the operating state of the engine 12, and a crankshaft 14 (see FIG. 2) of the engine 12 and An automatic transmission 20 connected to the axles 18a and 18b of the wheels 19a and 19b to shift the power from the engine 12 and transmit it to the axles 18a and 18b, and controls the automatic transmission 20 and the automobile 10 is running. An electronic control unit for transmission (hereinafter referred to as ATE) that also operates as a road surface gradient estimation device of the embodiment for estimating the road surface gradient. Comprises a U hereinafter) 29, a main electronic control unit that controls the entire vehicle (hereinafter, a main called ECU) 50, a. The main ECU 50 detects the shift position SP from the shift position sensor 52 that detects the operation position of the shift lever 51, the accelerator opening Acc from the accelerator pedal position sensor 54 that detects the depression amount of the accelerator pedal 53, and the brake pedal 55. The brake switch signal BSW from the brake switch 56 that detects the depression, the vehicle speed V from the vehicle speed sensor 58, and the like are input. In the embodiment, the shift position of the shift lever 51 includes a parking position (P position) used during parking, a reverse position (R position) for reverse travel, a neutral position (N position), and a normal drive position for forward travel. (D position), low position (L position), second position (2 position), etc. for applying the engine brake when the accelerator is off are prepared. The main ECU 50 is connected to the engine ECU 16 and the ATECU 29 via a communication port, and exchanges various control signals and data with the engine ECU 16 and the ATECU 29.

  As shown in FIG. 2, the automatic transmission 20 is configured as a transaxle device that transmits power from the engine 12 to the axles 18 a and 18 b, and an input-side pump impeller connected to the crankshaft 14 of the engine 12. A torque converter 24 with a lock-up clutch comprising a turbine runner 24b on the output side and an input shaft 21 connected to the turbine runner 24b of the torque converter 24 and a gear mechanism 27 and a differential gear 28 on the axles 18a and 18b. And a stepped transmission mechanism 26 that shifts the power input to the input shaft 21 and outputs it to the output shaft 22, and a hydraulic circuit 40 that drives and controls the transmission mechanism 26 (see FIG. 1).

  The speed change mechanism 26 is configured as a stepped transmission with six speeds, and includes a single pinion type planetary gear mechanism 30, a Ravigneaux type planetary gear mechanism 35, three clutches C1, C2, C3, and two brakes B1, B2 and a one-way clutch F1 are provided. The single pinion type planetary gear mechanism 30 includes a sun gear 31 as an external gear, a ring gear 32 as an internal gear arranged concentrically with the sun gear 31, and a plurality of gears meshed with the sun gear 31 and meshed with the ring gear 32. The pinion gear 33 and a carrier 34 that holds the plurality of pinion gears 33 so as to rotate and revolve freely. The sun gear 31 is fixed to the case of the automatic transmission 20, and the ring gear 32 is connected to the input shaft 21. The Ravigneaux planetary gear mechanism 35 includes two sun gears 36a and 36b as external gears, a ring gear 37 as an internal gear, a plurality of short pinion gears 38a meshing with the sun gear 36a, a sun gear 36b, and a plurality of short pinion gears 38a. The sun gear 36a includes a plurality of long pinion gears 38b that mesh with the ring gear 37, and a carrier 39 that connects the plurality of short pinion gears 38a and the plurality of long pinion gears 38b to hold the clutch C1 in a freely rotating and revolving manner. The sun gear 36b is connected to the carrier 34 via the clutch C3 and connected to the case of the automatic transmission 20 via the brake B1, and the ring gear 37 is connected to the carrier 34 of the single pinion planetary gear mechanism 30 via the brake C1. Connected to output shaft 22 Is, the carrier 39 is connected to the input shaft 21 via the clutch C2. Further, the carrier 39 is connected to the case of the automatic transmission 20 via the one-way clutch F1, and its rotation is regulated in one direction, and automatically via a brake B2 provided in parallel to the one-way clutch F1. It is connected to the case of the transmission 20.

  As shown in the operation table of FIG. 3, the speed change mechanism 26 switches between the first forward speed to the sixth speed, the reverse speed, and the neutral by engaging the clutches C1 to C3 and engaging and releasing the release brakes B1 and B2. Be able to. The reverse gear can be formed by engaging the clutch C3 and the brake B2 and releasing the clutches C1 and C2 and the brake B1. Further, the first forward speed can be formed by engaging the clutch C1 and releasing the clutches C2 and C3 and the brakes B1 and B2. In the first forward speed, the brake B2 is engaged during engine braking. The second forward speed can be formed by engaging the clutch C1 and the brake B1 and releasing the clutches C2 and C3 and the brake B2. The third forward speed can be formed by engaging the clutches C1 and C3 and releasing the clutch C2 and the brakes B1 and B2. The fourth forward speed can be formed by engaging the clutches C1 and C2 and releasing the clutch C3 and the brakes B1 and B2. The fifth forward speed can be formed by engaging the clutches C2 and C3 and releasing the clutch C1 and the brakes B1 and B2. The sixth forward speed can be formed by engaging the clutch C2 and the brake B1 and releasing the clutches C1, C3 and the brake B2. The neutral can be formed by releasing all of the clutches C1 to C3 and the brakes B1 and B2. FIG. 4 is a velocity diagram showing the relationship between the rotational speeds of the rotating elements of the speed change mechanism 26 in each of the first to sixth forward speeds and the reverse speed.

  Although not shown in detail, the ATECU 29 is configured as a microprocessor centered on a CPU. In addition to the CPU, a ROM for storing processing programs, a RAM for temporarily storing processing data, input / output ports, communication Provide ports. The AT ECU 29 receives an input shaft rotational speed Nin from an input shaft rotational speed sensor 42 attached to the input shaft 21 of the speed change mechanism 26 via an input port, and is input to each solenoid (not shown) of the hydraulic circuit 40. The drive signal is output through an output port. Further, as described above, the ATECU 29 communicates with the main ECU 50 and the engine ECU 16 and exchanges control signals and data with each other.

  The shift control of the automatic transmission 20 configured in this way is performed as a shift map for determining a shift stage based on the throttle opening and the vehicle speed V, and a normal map and an upshift shift line and a downshift shift when traveling on an uphill road. Prepare a map for uphill roads where the line is shifted to the higher vehicle speed side than the map for normal use, and whether it is a normal map or a map for uphill roads based on the road slope (road slope) θ Is selected, the gear position is determined based on the selected shift map, the throttle opening degree, and the vehicle speed V, and the clutch (brake) necessary to achieve the determined gear position is engaged. Or by releasing. Engagement and release of the clutch are performed by setting a hydraulic pressure command Prel for the release-side clutch and a hydraulic pressure command Papp for the engagement-side clutch, and driving and controlling a corresponding solenoid of the hydraulic circuit 40 based on the set hydraulic pressure commands Prel and Papp. To do so.

  Next, the operation of the automobile 10 configured as described above, particularly the operation when estimating the road surface gradient θ will be described. FIG. 5 is a flowchart showing an example of a road gradient estimation processing routine executed by the CPU of the ATECU 29. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the road surface gradient estimation processing routine is executed, the CPU of the ATECU 29 first starts the engine torque Te, the engine rotational speed Ne, the vehicle speed V, the input shaft rotational speed Nin from the input shaft rotational speed sensor 42, and the speed change state of the transmission mechanism 26. A process for inputting data necessary for the process is executed (step S100). Here, the engine torque Te derived from the throttle opening (not shown) of the engine 12 is input from the engine ECU 16 via the main ECU 50 by communication. The engine speed Ne is calculated based on the rotation angle of the crankshaft 14 detected by the crank angle sensor 15 and is input from the engine ECU 16 via the main ECU 50 by communication. Further, the vehicle speed V detected by the vehicle speed sensor 58 is input from the main ECU 50 by communication. Further, the speed change state of the speed change mechanism 26 indicates the current speed and its gear ratio γc when no change (shift) is instructed, and the speed before the speed and its gear ratio γbe when the speed is instructed. And the gear stage after the shift and the gear ratio γaf stored as the state of the transmission mechanism 26 are input.

  When the data necessary for processing is input in this way, the input torque Tin, which is the torque acting on the input shaft 21, is calculated by dividing the engine torque Te multiplied by the engine rotational speed Ne by the input shaft rotational speed Nin (step S110). ), It is determined whether or not shifting is in progress (step S120). If it is determined that the gear is not being shifted, the non-shifting output torque calculation process of FIG. 6 is executed (step S130). In the non-shifting output torque calculation process, as shown in FIG. 6, the gear ratio γc of the current shift stage is set to the gear ratio γ for calculating the output torque (step S300), and the input gear Tin and the set gear ratio γ are set. Is calculated by calculating an output torque Tout, which is a torque output to the output shaft 22 by the following equation (1) (step S310). Here, “Loss” in the equation (1) indicates a gear loss, “Gd” indicates a gear ratio of the differential gear 28, “r” indicates a tire radius of the wheels 19a and 19b, and “R” indicates traveling. Resistance indicates “M” indicates vehicle weight.

  Tout = Tin × γ−Loss (1)

  When the output torque Tout is calculated, the reference acceleration αbase is set based on the calculated output torque Tout (step S140). Here, the reference acceleration α is, for example, an acceleration obtained when traveling on a flat road with the output torque Tout, and is calculated based on the output torque Tout, vehicle weight, running resistance, differential gear ratio, tire diameter, and the like. can do. Then, the actual acceleration α, which is the actual acceleration, is calculated by dividing the deviation between the inputted current vehicle speed V and the previous vehicle speed by the execution time interval ΔT of this routine (step S150), and the set reference acceleration αbase and the actual acceleration are calculated. The road surface gradient θ is estimated based on the deviation from the acceleration α (step S160), and this routine is terminated.

  If it is determined in step S120 that shifting is in progress, a shifting pattern is determined (step S170). Here, as a shift pattern, in the embodiment, PowerOnUp in which the engine 12 is upshifted in the power-on state, CoastDown in which the engine 12 is downshifted in the coast state, PowerOffUp in which the engine 12 is upshifted in the power-off state, There are ManualDown for downshifting by a shift operation (L position, 2 position, etc.), and PowerOnDown for downshifting when the engine 12 is powered on. Now, consider a case where the gear position is changed by changing the clutch that releases one of the two clutches (brake) and engages the other. In this case, when the shift pattern is any of PowerOnUp, CoastDown, PowerOffUp, and ManualDown, the change of the gear position is transferred in the slip engagement state from the release side clutch to the engagement side clutch (torque phase). Thereafter, the engaging force of the clutch on the engaging side is gradually increased to change the rotational speed of the input shaft 21 to a rotational speed corresponding to the gear stage after the shift (inertia phase). Further, when the shift pattern is PowerOnDown, the shift stage is changed by rotating the rotational speed of the input shaft 21 according to the shift stage after the shift by the output torque from the engine 12 with the clutch on the disengagement side being slip-engaged. By changing to the speed, and engaging the clutch on the engagement side when it is determined that the deviation between the rotational speed of the input shaft 21 and the rotational speed corresponding to the gear position after the shift is less than a predetermined value and the rotation is synchronized. Done.

  When the determination result of the shift pattern in step S170 is a pattern other than PowerOnDown, that is, any pattern of PowerOnUp, CoastDown, PowerOffUp, or ManualDown (step S180), the first pattern shift output torque calculation process of FIG. 7 is executed. Thus, the output torque Tout is calculated (step S190), the road surface gradient θ is estimated based on the calculated output torque Tout (steps S140 to S160), and this routine ends. On the other hand, when the shift pattern determination result is the PowerOnDown pattern (step S180), the output torque Tout is calculated by executing the second pattern shift output torque calculation process of FIG. 8 (step S200), and the calculated output The road surface gradient θ is estimated based on the torque Tout (steps S140 to S160), and this routine is finished. Hereinafter, details of the first pattern shift output torque calculation process of FIG. 7 and the second pattern shift output torque calculation process of FIG. 8 will be described in order.

  In the first pattern shift output torque calculation process of FIG. 7, first, the start of the inertia phase is determined (step S400). The start of the inertia phase can be determined by detecting a change in the input shaft rotation speed Nin. When it is determined that the inertia phase has not started, that is, when it is determined that torque transmission is being transferred from the release side clutch to the engagement side clutch (torque phase), the torque capacity Trel of the release side clutch The torque capacity Tapp of the engagement side clutch is set (step S410), and the torque sharing ratio Krel, which is the ratio of the torque shared by the release side clutch to the input torque before the shift, is set to the input torque after the shift. On the other hand, a torque sharing ratio Kapp, which is a ratio of torque shared by the clutch on the engagement side, is set (step S420). Here, the torque capacity Trel is estimated based on the hydraulic pressure command Prel set for the release-side clutch, and the torque capacity Tapp is estimated based on the hydraulic pressure command Papp set for the engagement-side clutch. To be estimated. Further, the torque sharing ratios Krel and Kapp are obtained and stored in advance for each shift stage before and after the shift, and when the shift stages before and after the shift are given, the corresponding torque sharing ratios Krel and Kapp are stored from the stored relationship. It was set by deriving each. Then, based on the set torque capacities Trel, Tapp and the torque sharing ratios Krel, Kapp, the output torque Tout is calculated by the following equation (2) (step S430), and the first pattern shift output torque calculation process is terminated. . In the equation (2), “γbe” indicates the gear ratio at the shift stage before the shift, and “γaf” indicates the gear ratio at the shift stage after the shift. Here, in Expression (2), the first term on the right side means the torque transmitted by the disengagement side clutch, and the second term on the right side means the torque transmitted by the engagement side clutch. That is, the output torque Tout can be calculated by the sum of the torque transmitted by the disengagement side clutch and the torque transmitted by the engagement side clutch.

  Tout = (γbe / Krel) ・ Trel + (γaf / Kapp) ・ Tapp (2)

  If it is determined in step S400 that the inertia phase has started, the gear ratio γaf at the speed stage after the shift is set as the output torque calculation gear ratio γ (step S440), and output is performed using the above-described equation (1). The torque Tout is calculated (step S450), and the first pattern shift output torque calculation process is terminated. When the inertia phase is started, torque transmission is transferred from the release-side clutch to the engagement-side clutch, and torque transmission is performed by the engagement-side clutch with a gear ratio in the gear stage after the shift. Therefore, the output torque Tout can be calculated based on the input torque Tin and the gear ratio γaf after the shift.

  Next, the second pattern shift output torque calculation process of FIG. 8 will be described. In the second pattern shift output torque calculation process, first, the rotational angular acceleration dωin / dt of the input shaft 21 is calculated by converting the input shaft rotational speed Nin to the angular speed ωin and differentiating it (step S500). It is determined whether or not the rotation speed is synchronized with the rotation speed after the shift (step S510). This determination can be made, for example, by determining whether or not the deviation between the input shaft rotation speed Nin and the vehicle speed V and the rotation speed obtained by multiplying the vehicle speed V by the gear ratio at the speed stage after the shift is less than a predetermined value. If it is determined that the rotational speed of the input shaft 21 is not yet synchronized with the rotational speed after the shift (step S510), the torque capacity Telo of the release side clutch and the torque capacity Tapp of the engagement side clutch are set. (Step S520), the torque sharing ratio Krel of the release side clutch and the torque sharing ratio Kapp of the engagement side clutch are set (step S530). Then, based on the set torque capacity Trel, Tapp, the torque sharing ratios Krel, Kapp and the calculated rotational angular acceleration dωin / dt of the input shaft 21, the output torque Tout is calculated by the following equation (3) (step S540). Then, the second pattern shift output torque calculation process is terminated. Here, the first term on the right side of Equation (3) is the right side of Equation (2) described above, and the second term on the right side of Equation (3) is the inertia term. In Expression (3), “Iin” represents the inertia moment of the inertial system before the input shaft 21, and “A” is a coefficient determined in advance for each shift stage before and after the shift. When the shift pattern is PowerOnDown, as described above, the rotational speed of the input shaft 21 is shifted after the shift while the disengaged clutch is slip-engaged until the engaged clutch is engaged. The inertial force generated in accordance with the change in the rotation speed of the inertial system is transmitted to the output shaft 22 side. Therefore, the output torque Tout can be calculated more accurately by reflecting such inertial force on the output torque Tout.

  Tout = (γbe / Krel) ・ Trel + (γaf / Kapp) ・ Tapp + A ・ (Iin ・ dωin / dt) (3)

  If it is determined in step S510 that the engagement-side clutch is engaged, the torque capacity Trel of the release-side clutch and the engagement-side clutch are the same as in steps S410 to S430 in the first pattern shift output torque calculation process. Is set (step S550), the torque sharing ratio Krel of the disengagement side clutch and the torque sharing ratio Kapp of the engaging side clutch are set (step S560), and the set torque capacity Trel, Based on Tapp and the torque sharing ratios Krel and Kapp, the output torque Tout is calculated by the above-described equation (2) (step S570), and the second pattern shift output torque calculating process is terminated. When the shift pattern is PowerOnDown, torque transmission is transferred from the release-side clutch to the engagement-side clutch when the rotation speed of the input shaft 21 is synchronized with the rotation speed after the shift. ) Can be used to accurately calculate the output torque Tout.

  FIG. 9 shows how the input shaft rotation speed Nin, the hydraulic pressure commands Papp, Prel, the input torque Tin, and the output torque Tout change with time during the upshift. In the embodiment, as shown in FIG. 9, when a shift is started at time t0, the hydraulic pressure command Prel is set so as to stand by in a state where the hydraulic pressure for the release side clutch is lowered by one step, and for the engagement side clutch. The hydraulic pressure command Papp is set so that fast fill and low pressure standby are executed. As a result, the release-side clutch is slip-engaged, and the engagement-side clutch is held near the stroke end pressure. Subsequently, a sweep drain process for setting a hydraulic pressure command Prel is executed and engaged so that the hydraulic pressure for the release-side clutch gradually decreases at time t1 after a predetermined time has elapsed from the standby state for the engagement-side clutch. By executing a sweep apply process for setting the hydraulic pressure command Papp so that the hydraulic pressure for the side clutch gradually increases, a torque phase for transferring torque transmission from the release side clutch to the engagement side clutch is executed. During this time, the output torque Tout is calculated by the sum of the torque transmitted by the release-side clutch and the torque transmitted by the engagement-side clutch, so that the calculated output torque Tout follows the torque pull-in in the torque phase. The output torque Tout substantially coincides with the actual output torque. Then, when the input shaft rotation speed Nin begins to decrease at time t2 and the inertia phase starts, a hydraulic pressure command Papp is set so as to gradually increase the hydraulic pressure for the engagement side clutch, and the engagement clutch slip engagement is set. As a result, an inertia phase is executed in which the rotational speed of the input shaft 21 is changed to a rotational speed corresponding to the gear position after the shift. During this time, torque transmission is performed only by the clutch on the engagement side. Therefore, by calculating the output torque Tout based on the input torque Tin and the gear ratio γaf at the gear stage after the shift, the calculated value of the output torque Tout The actual value can be substantially matched. In this way, the output torque Tout calculated can be made substantially coincident with the actual output torque even during the shift, so that the road surface gradient θ can be accurately estimated. In the inertia phase, reduction processing for temporarily reducing the torque of the engine 12 is executed in order to suppress fluctuations in the output torque. During this time, the input torque Tin is also reduced, and the output is based on the input torque Tin. Torque Tout is calculated.

  FIG. 10 is an explanatory diagram showing changes over time in the input shaft rotation speed Nin, hydraulic pressure commands Papp, Prel, input torque Tin, and output torque Tout during the second pattern shift in the embodiment. As shown in FIG. 10, the oil pressure command Papp is set so that fast fill and low pressure standby are executed for the engagement side clutch, and the engagement side clutch is held near the stroke end pressure, and the release side The hydraulic pressure on the clutch is lowered to slip the clutch on the disengagement side. When an increase in the rotational speed of the input shaft 21 is started at time t1 due to slip engagement of the release side clutch, the hydraulic pressure command Prel for the release side clutch is waited at a low pressure, and the rotational speed of the input shaft 21 is changed to Increase the rotation speed according to the gear position. Here, when the shift pattern is PowerOnDown, since the engine 12 performs a downshift with the power on, the input shaft 21 is rotated by the torque from the engine 12 with the disengaged clutch slip-engaged. The speed is increased to a rotational speed corresponding to the speed stage after the shift. Therefore, the output torque Tout can be calculated by the sum of the torque transmitted by the disengagement side clutch, the torque transmitted by the engagement side clutch, and the torque transmitted from the inertial system. When the rotational speed of the input shaft 21 substantially coincides with the rotational speed corresponding to the speed stage after the shift, the torque transmission is released on the release side by executing a sweep apply process for gradually increasing the hydraulic pressure command Papp for the engagement side clutch. From the clutch to the clutch on the engagement side. During this time, since the rotational speed of the input shaft 21 does not change, the output torque Tout can be calculated by the sum of the torque transmitted by the disengagement side clutch and the torque transmitted by the engagement side clutch.

  According to the road surface gradient estimation device of the embodiment described above, the output torque Tout output to the output shaft 22 of the automatic transmission 20 is calculated, and the reference acceleration αbase and the actual acceleration α obtained based on the calculated output torque Tout. The transmission torque transmitted by the disengagement clutch when the gear stage is changed by changing the clutch that releases one of the two clutches (brake) and engages the other. Since the output torque Tout is calculated from the sum of the transmission torque transmitted by the clutch on the engagement side (formula (2)), the difference between the calculated value of the output torque Tout and the actual value can be reduced, and the shift stage Even when the vehicle is being changed, the road surface gradient θ can be estimated more accurately. Moreover, when the shift pattern is PowerOnDown, the transmission torque transmitted by the release side clutch and the transmission transmitted by the engagement side clutch while the rotation speed of the input shaft 21 is changing to the rotation speed after the shift. Since the output torque Tout is calculated by the equation (3) in which an inertia term is added to the calculation equation of the torque and the sum, the output torque Tout can be calculated more accurately regardless of the shift pattern.

  In the embodiment, when the shift pattern is a pattern other than PowerOnDown (any pattern of PowerOnUp, CoastDown, PowerOffUp, or ManualDown), the gear ratio γaf at the shift stage after the shift is calculated as an output torque during the inertia phase. The output torque Tout is calculated according to the above-described equation (1) based on the input torque Tin and the gear ratio γ as the gear ratio γ for use, but the inertial term is expressed in the equation (2) instead of the equation (1). The output torque Tout may be calculated using the added expression (3).

  In the embodiment, when the shift pattern is a pattern other than PowerOnDown (a pattern of either PowerOnUp, CoastDown, PowerOffUp, or ManualDown), until the inertia phase is started (torque phase), the above-described formula does not include the inertia term. Although the output torque Tout is calculated using (2), the output torque Tout may be calculated using Expression (3) including an inertia term. In this case, since the rotational speed of the input shaft 21 does not change in the torque phase, the inertia term is 0, which is substantially the same as the equation (2). Similarly, when the shift pattern is PowerOnDown, the output torque Tout is calculated by Expression (3) including the inertia term until the rotation speed of the input shaft 21 is synchronized with the rotation speed after the shift, and the rotation speed of the input shaft 21 is calculated. Is synchronized with the rotational speed after the shift, the output torque Tout is calculated by the equation (2) not including the inertia term. However, after the rotational speed of the input shaft 21 is synchronized with the rotational speed after the shift. However, the output torque Tout may be calculated by the equation (3) including the inertia term.

  In the embodiment, the road surface gradient estimation device of the present invention is applied to a device equipped with a transmission mechanism 26 for six-speed shift from forward 1st to 6-th. However, the present invention is not limited to this. The present invention may be applied to a transmission having any number of stages such as a 5-speed shift and an 8-speed shift.

  Here, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. The engine 12 of the embodiment corresponds to the “prime mover” of the present invention, and the automatic transmission 20 corresponds to the “transmission”. Here, the “motor” is not limited to the engine 12 as an internal combustion engine, but may be an electric motor capable of outputting traveling power or a hybrid system in which the internal combustion engine and the electric motor are combined. Further, the “transmission” is not limited to one provided with a torque converter, and may be one provided with a starting clutch without a torque converter. In this case, the input shaft of the transmission may be the output shaft of the starting clutch instead of the turbine shaft. The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. It is an example for specifically explaining the best mode for doing so, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the gist of the present invention. Of course you get.

  The present invention is applicable to the automobile industry.

  10 automobiles, 12 engines, 14 crankshafts, 15 crank angle sensors, 16 engine electronic control units (engine ECUs), 18a, 18b axles, 19a, 19b wheels, 20 automatic transmissions, 21 input shafts, 22 output shafts, 24 Torque converter, 24a pump impeller, 24b turbine runner, 26 transmission mechanism, 27 gear mechanism, 28 differential gear, 29 transmission electronic control unit (ATECU), 30 single-pinion planetary gear mechanism, 31 sun gear, 32 ring gear, 33 Pinion gear, 34 carrier, 35 Ravigneaux planetary gear mechanism, 36a, 36b sun gear, 37 ring gear, 38a short pinion gear, 38b long pinion gear, 39 carrier, 40 hydraulic circuit, 42 input shaft Rotational speed sensor, 50 main electronic control unit (main ECU), 51 shift lever, 52 shift position sensor, 53 accelerator pedal, 54 accelerator pedal position sensor, 55 brake pedal, 56 brake switch, 58 vehicle speed sensor, C1-C3 clutch, B1, B2 Brake.

Claims (3)

A prime mover and a transmission capable of changing a gear position by changing one of a plurality of engaging elements and releasing the other, and outputting power from the prime mover via the transmission. A road surface gradient estimation device that is mounted on a vehicle that travels and estimates the gradient of the road surface on which the vehicle is traveling,
While the gear stage of the transmission is being changed, a disengagement-side transmission torque that is a torque transmitted by a disengagement-side engagement element and an engagement-side engagement element are transmitted among the plurality of engagement elements. And calculating the output torque output to the output shaft of the transmission using the calculation formula of the sum of the calculated disengagement side transmission torque and engagement side transmission torque. Then, the road gradient is estimated based on the calculated output torque and the acceleration of the vehicle. The road surface gradient estimation device according to claim 1,
The disengagement side transmission torque is obtained by dividing the gear ratio at the gear stage before the shift by the sharing ratio that is the ratio of the torque that is shared by the disengagement engagement element with respect to the input torque of the transmission. Calculated by multiplying the torque capacity of the engagement element on the release side,
The engagement-side transmission torque is obtained by dividing the gear ratio at the gear stage after the shift by a sharing ratio that is a ratio of torque shared by the engagement element on the engagement side with respect to the input torque of the transmission. Further, the road surface gradient estimation device is calculated by multiplying the torque capacity of the engagement element on the engagement side. The road surface gradient estimation device according to claim 1 or 2,
While the rotational speed of the input shaft of the transmission is being changed to the rotational speed corresponding to the gear position after the shift, the transmission is transmitted to the output shaft based on the rotational change of the inertia system on the front stage side of the input shaft. A road surface gradient estimating apparatus, wherein an output is calculated by adding an inertia term for calculating a torque to be calculated to the calculation formula.

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