Source: http://www.google.com/patents/US5434780?dq=6317900
Timestamp: 2016-05-01 05:29:39
Document Index: 462337656

Matched Legal Cases: ['art 63', 'art 67', 'art 51', 'art 51', 'art 51', 'art 55', 'art 58', 'art 51', 'art 51', 'art 55', 'art 55', 'art 51', 'art 55', 'art 55', 'art 58', 'art 51', 'art 58', 'art 58', 'art 63', 'art 67']

Patent US5434780 - Automatic transmission control system with variable lockup timing - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inPatentsAn automatic transmission control system for a transmission which is installed in a vehicle and whose torque converter is provided with a lockup mechanism; comprising a vehicle weight estimation device for estimating the weight of the vehicle; a gradient estimation device for estimating a gradient on...http://www.google.com/patents/US5434780?utm_source=gb-gplus-sharePatent US5434780 - Automatic transmission control system with variable lockup timingAdvanced Patent SearchPublication numberUS5434780 APublication typeGrantApplication numberUS 08/105,120Publication dateJul 18, 1995Filing dateAug 12, 1993Priority dateSep 8, 1992Fee statusPaidAlso published asUS5598336Publication number08105120, 105120, US 5434780 A, US 5434780A, US-A-5434780, US5434780 A, US5434780AInventorsMasayuki Kume, Junichi IshiiOriginal AssigneeHitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.Export CitationBiBTeX, EndNote, RefManPatent Citations (12), Referenced by (31), Classifications (43), Legal Events (4) External Links: USPTO, USPTO Assignment, EspacenetAutomatic transmission control system with variable lockup timing
US 5434780 AAbstract
An automatic transmission control system for a transmission which is installed in a vehicle and whose torque converter is provided with a lockup mechanism; comprising a vehicle weight estimation device for estimating the weight of the vehicle; a gradient estimation device for estimating a gradient on which the vehicle is running; a standard lockup line selector for storing therein standard lockup lines which correspond respectively to the specified gear shift ratios of a speed change gear included in the transmission, and for selecting that one of the stored standard lockup lines which corresponds to the gear shift ratio in the present state of the vehicle; a lockup line corrector for correcting the selected standard lockup line in accordance with the estimated vehicle weight and the estimated gradient; and a lockup signal output device for deciding a timing of lockup "ON" or lockup "OFF" by the use of the corrected lockup line, and for delivering a lockup signal to the lockup mechanism (a lockup solenoid) at the decided timing. Since the lockup timing is varied in accordance with a running resistance, the drivability of the vehicle is enhanced.
1. An automatic transmission control system for a transmission which has a speed change gear, a torque converter, and a lockup mechanism for the torque converter; comprising:running resistance grasp means for grasping either of a running resistance or a value of at least one factor which exerts influence on the running resistance; standard lockup line memory means for storing therein a single lockup line which corresponds to a condition when the running resistance is standard; lockup line correction means for correcting the single lockup line in accordance with either of said running resistance or said value of the influential factor as grasped by said running resistance grasp means; and lockup signal output means for deciding a timing of either lockup "ON" or lockup "OFF" in accordance with the lockup line corrected by said lockup line correction means, and for delivering a lockup signal to said lockup mechanism so as to drive it at the decided timing. 2. An automatic transmission control system as defined in claim 1, wherein:said speed change gear is a speed change gear of multiple gear shift stages, so that said standard lockup line memory means stores therein a plurality of lockup lines which correspond respectively to the specified gear shift stages; standard lockup line selection means is further comprised for selecting one lockup line corresponding to the gear shift stage in a present state, from among the plurality of lockup lines stored in said standard lockup line memory means; and said lockup line correction means corrects the lockup line selected by said standard lockup line selection means. 3. An automatic transmission control system as defined in claim 2, further comprising:input load detection means for detecting either of a quantity of fuel injection or a magnitude which has a predetermined relation with the quantity of fuel injection, and vehicle speed detection means for detecting a speed of a vehicle in which said transmission is installed; the plurality of stored lockup lines of said standard lockup line memory means being set under a condition that the vehicle speed and either of said quantity of fuel injection or said magnitude relating therewith are used as parameters; said lockup signal output means delivering the lockup signal upon deciding that a time at which the detected vehicle speed and the detected one of the quantity of fuel injection and the magnitude relating therewith have reached a point on the selected and corrected lockup line is the timing of either of said lockup "ON" or said lockup "OFF". 4. An automatic transmission control system as defined in claim 1, further comprising:input load detection means for detecting either of a quantity of fuel injection or a magnitude which has a predetermined relation with the quantity of fuel injection, and vehicle speed detection means for detecting a speed of a vehicle in which said transmission is installed; the stored lockup line of said standard lockup line memory means being set under a condition that the vehicle speed and either of said quantity of fuel injection or said magnitude relating therewith are used as parameters; said lockup signal output means delivering the lockup signal upon deciding that a time at which the detected vehicle speed and the detected one of the quantity of fuel injection and the magnitude relating therewith have reached a point on the corrected lockup line is the timing of either of said lockup "ON" or said lockup "OFF". 5. An automatic transmission control system as defined in claim 1, wherein:the factor which exerts influence on the running resistance is a weight of a vehicle in which said transmission is installed; and said running resistance grasp means includes vehicle weight grasp means for grasping the vehicle weight. 6. An automatic transmission control system as defined in claim 1, wherein:the factor which exerts influence on the running resistance is a gradient on which a vehicle having said transmission installed therein is running; and said running resistance grasp means includes grade grasp means for grasping the grade. 7. An automatic transmission control system as defined in claim 1, wherein:the factors which exert influence on the running resistance are a weight of a vehicle in which said transmission is installed, and a gradient on which said vehicle is running; and said running resistance grasp means includes vehicle weight grasp means for grasping the vehicle weight, and gradient grasp means for grasping the gradient. 8. An automatic transmission control system for a transmission which has a speed change gear, a torque converter, and a lockup mechanism for the torque converter; comprising:running resistance grasp means for grasping either of a running resistance or a value of at least one factor which exerts influence on the running resistance; standard lockup line memory means for storing therein a single lockup line which corresponds to a condition when the running resistance is standard; standard gear shift line memory means for storing therein a gear shift line which corresponds to the condition when the running resistance is standard; lockup line correction means for correcting the single lockup line in accordance with either of said running resistance or said the value of the influential factor as grasped by said running resistance grasp means; gear shift line correction means for correcting the gear shift line in accordance with either of said running resistance or said value of the influential factor as grasped by said running resistance grasp means; lockup signal output means for deciding a timing of either lockup "ON" or lockup "OFF" in accordance with the lockup line corrected by said lockup line correction means, and for delivering a lockup signal to said lockup mechanism so as to drive it at the decided timing; and shift signal output means for deciding a timing of alteration of a gear shift ratio of said speed change gear in accordance with the gear shift line corrected by said gear shift line correction means, and for delivering a shift signal to said speed change gear so as to drive it at the decided timing. 9. An automatic transmission control system as defined in claim 8, wherein:said speed change gear is a speed change gear of multiple gear shift stages, so that said standard lockup line memory means stores therein a plurality of lockup lines which correspond respectively to the specified gear shift stages, while said standard gear shift line memory means stores therein a plurality of gear shift lines which correspond respectively to said gear shift stages; standard lockup line selection means is further comprised for selecting one lockup line corresponding to the gear shift stage in a present state, from among the plurality of lockup lines stored in said standard lockup line memory means; standard gear shift line selection means is further comprised for selecting one gear shift line corresponding to the gear shift stage in the present state, from among the plurality of gear shift lines stored in said standard gear shift line memory means; said lockup line correction means corrects the lockup line selected by said standard lockup line selection means; and said gear shift line correction means corrects the gear shift line selected by said standard gear shift line selection means. 10. An automatic transmission control system as defined in claim 9, further comprising:input load detection means for detecting either of a quantity of fuel injection or a magnitude which has a predetermined relation with the quantity of fuel injection, and vehicle speed detection means for detecting a speed of a vehicle in which said transmission is installed; the plurality of stored lockup lines of said standard lockup line memory means being set under a condition that the vehicle speed and either of said quantity of fuel injection or said magnitude relating therewith are used as parameters; the plurality of stored gear shift lines of said standard gear shift line memory means being set under the condition that the vehicle speed and either of said quantity of fuel injection or said magnitude relating therewith are used as parameters; said lockup signal output means delivering the lockup signal upon deciding that a time at which the detected vehicle speed and the detected one of the quantity of fuel injection and the magnitude relating therewith have reached a point on the selected and corrected lockup line is the timing of either of said lockup "ON" or said lockup "OFF"; said shift signal output means delivering the shift signal upon deciding that a time at which the detected vehicle speed and the detected one of the quantity of fuel injection and the magnitude relating therewith have reached a point on the selected and corrected gear shift line is the timing of the alteration of the gear shift ratio. 11. An automatic transmission control system as defined in claim 8, further comprising:input load detection means for detecting either of a quantity of fuel injection or a magnitude which has a predetermined relation with the quantity of fuel injection, and vehicle speed detection means for detecting a speed of a vehicle in which said transmission is installed; the stored lockup line of said standard lockup line memory means being set under a condition that the vehicle speed and either of said quantity of fuel injection or said magnitude relating therewith are used as parameters; the stored gear shift line of said standard gear shift line memory means being set under the condition that the vehicle speed and either of said quantity of fuel injection or said magnitude relating therewith are used as parameters; said lockup signal output means delivering the lockup signal upon deciding that a time at which the detected vehicle speed and the detected one of the quantity of fuel injection and the magnitude relating therewith have reached a point on the corrected lockup line is the timing of either of said lockup "ON" or said lockup "OFF"; said shift signal output means delivering the shift signal upon deciding that a time at which the detected vehicle speed and the detected one of the quantity of fuel injection and the magnitude relating therewith have reached a point on the corrected gear shift line is the timing of the alteration of the gear shift ratio. 12. An automatic transmission control system as defined in claim 8, wherein:the factor which exerts influence on the running resistance is a weight of a vehicle in which said transmission is installed; and said running resistance grasp means includes vehicle weight grasp means for grasping the vehicle weight. 13. An automatic transmission control system as defined in claim 8, wherein:the factor which exerts influence on the running resistance is a gradient on which a vehicle having said transmission installed therein is running; and said running resistance grasp means includes gradient grasp means for grasping the gradient. 14. An automatic transmission control system as defined in claim 8, wherein:the factors which exert influence on the running resistance are a weight of a vehicle in which said transmission is installed, and a gradient on which said vehicle is running; and said running resistance grasp means includes vehicle weight grasp means for grasping the vehicle weight, and gradient grasp means for grasping the gradient. Description
The present invention has been made in view of the problem of the prior art as explained above, and it has for its object to provide an automatic transmission control system which can vary the timings of lockup in accordance with the changes of a running resistance, thereby attaining an enhanced drivability.
FIG. 1 is a circuit block diagram showing an embodiment of an automatic transmission control system according to the present invention;
FIG. 11 is a flow chart showing steps for evaluating a turbine torque (Tt1) in an example;
FIG. 12 is a flow chart showing steps for evaluating a turbine torque (Tt2) in another example;
FIGS. 20A and 20B are graphs showing the relationships between a vehicle weight (W) and respective correction magnitudes (αW, βW) for the vehicle weight in an example; and
Now, an embodiment of an automatic transmission control system according to the present invention will be described with reference to the accompanying drawings.
As illustrated in FIG. 1, the automatic transmission control system for a transmission in this embodiment is constructed comprising an acceleration sensor 11 which detects the acceleration a of a vehicle such as an automobile, a throttle valve opening (TVO) sensor 12 which detects the opening TVO of a throttle valve for the engine of the vehicle, a vehicle speed sensor 13 which detects the speed V one the vehicle, an engine r.p.m. sensor 14 which detects the r.p.m. or revolution number Ne of the output shaft of the engine, a turbine r.p.m. sensor 15 which detects the r.p.m. or revolution number Nt of a turbine constituting the torque converter of the transmission, a transmission control unit 20 which controls the transmission, an input interface 31 for the transmission control unit 20, and an output interface 32 for the transmission control unit 20. By the way, in this embodiment, the TVO sensor 12 may well be substituted by means for grasping the quantity of fuel injection or means for grasping the quantity of intake air. That is, in this embodiment, the throttle valve opening TVO may well be replaced with the quantity of fuel injection or the quantity of intake air (which has a predetermined relationship with the quantity of fuel injection).
The neural network learns the vehicle weight W in such a way that the weighting factors of the respective synapses are so altered as to diminish the error (E) between the real weight (Wre) of the vehicle and the vehicle weight (We) estimated from the inputs of the acceleration a, vehicle speed V and throttle valve opening TVO. In order to cope with various aspects of depressing the accelerator pedal of the vehicle, accelerating response waveforms are previously measured by experiments while the values of the vehicle weight and the throttle valve opening are changed for the identical automobile. Subsequently, the time-serial waveforms of the acceleration a, vehicle speed V and throttle valve opening TVO are input to the neural vehicle weight estimation portion 43, and the neural network is caused to deliver the estimated vehicle weight We. Next, the error E of the estimated vehicle weight We with respect to the real vehicle weight Wre is calculated by a subtracter 47. Then, a weighting factor alteration portion 46 alters the weighting factors of the synapses so as to diminish the error E. As an algorithm for altering the weighting factors, a back-propagation algorithm is typical, but another algorithm may well be employed. By the way, the alterations of the weighting factors are made basically before the shipping of the vehicle. Therefore, the weighting factor alteration portion 46 and the subtracter 47 may exist before the shipping of the vehicle, and they need not exist after the shipping. It is considered, however, that the estimation portion 43 might fail to accurately estimate the vehicle weight W on account of the secular variations of the outputs of the respective sensors 11, 12 and 13. Therefore, the weighting factor alteration portion 46 and the subtracter 47 may well be kept mounted even after the shipping of the vehicle so as to alter the weighting factors regularly or at need.
As illustrated in FIG. 4, the gradient estimation means 23 includes an engine torque calculation portion 40 which has the map of engine output characteristics and which evaluates an engine torque Te corresponding to the measured throttle valve opening TVO and engine revolution number Ne by the use of the engine output characteristics map, a turbine torque calculation portion 50 which evaluates the torque Tt of the turbine constituting the torque converter, a gradient resistance torque calculation portion 60 which evaluates the gradient resistance torque T.sub.θ of the axle of the vehicle by the use of the evaluated turbine torque Tt, and a gradient calculation portion 70 which evaluates the gradient θ of the road being traveled by the vehicle from the evaluated gradient resistance torque T.sub.θ.
The gradient resistance torque calculation portion 60 is provided with multipliers 61 and 62 which evaluate the total torque Ttotal of the axle in such a way that the turbine torque Tt evaluated by the turbine torque calculation portion 50 is multiplied by the gear ratio r of the speed change gear and the gear ratio rD of a differential gear constituting the speed change gear, respectively. It is also provided with an accelerating resistance calculation part 63 which evaluates an accelerating resistance torque Ti in such a way that the inertial weight of the vehicle (that is, the vehicle weight W+a weight Wr corresponding to the rotating parts of the vehicle) is multiplied by the detected acceleration a and the effective radius rW of each tyre of the vehicle. In addition, the gradient resistance torque calculation portion 60 is provided with a subtracter 64 which subtracts the accelerating resistance torque Ti from the total torque Ttotal of the axle, a flatland running resistance torque calculation part 67 which evaluates a flatland (or level ground) running resistance torque Tf, a subtracter 65 which evaluates the gradient resistance torque T.sub.θ in such a way that a difference obtained by subtracting the accelerating resistance torque Ti from the total torque Ttotal has the flatland running resistance torque Tf further subtracted therefrom, and a low-pass filter 66 which removes the high-frequency components of the evaluated grade resistance torque T.sub.θ.
Besides, the gradient calculation portion 70 is provided with a divider 71 which evaluates the gradient θ in such a way that the gradient resistance torque T.sub.θ evaluated by the gradient resistance torque calculation portion 60 is divided by the product between the vehicle weight W and the effective radius rW of the tyre.
As illustrated in FIG. 5, the turbine torque calculation portion 50 is provided with a torque ratio/capacity coefficient calculation part 51 which has the map of torque converter characteristics and which evaluates a capacity coefficient τ and a torque ratio t corresponding to the detected engine revolution number Ne and turbine revolution number Nt by the use of the torque converter characteristics map. It is also provided with a multiplier 52 which evaluates Ne 2 by squaring the detected engine revolution number Ne, a multiplier 53 which evaluates an engine torque Te in such a way that the capacity coefficient τ evaluated by the torque converter characteristics calculation part 51 is multiplied by the output Ne 2 of the multiplier 52, and a multiplier 54 which evaluates a turbine torque Tt2 in such a way that the engine torque Te is multiplied by the torque ratio t evaluated by the torque ratio/capacity coefficient calculation part 51. In addition, the turbine torque calculation portion 50 is provided with an accessory torque calculation part 55 which evaluates a torque Tacc required for driving the accessories of the vehicle, such as an air conditioner mounted on the automobile. It is also provided with a subtracter 56 which subtracts the accessory torque Tacc from the engine torque Te evaluated by the engine torque calculation portion 40, and a multiplier 57 which evaluates a turbine torque Tt1 in such a way that an engine torque Te ' obtained by subtracting the accessory torque Tacc from the engine torque Te is multiplied by the torque ratio t. Further, the calculation portion 50 is provided with a turbine torque selection part 58 which selects the more precise one of the turbine torque Tt1 evaluated using the engine output characteristics and the turbine torque Tt2 evaluated using the torque converter output characteristics. Incidentally, a pump torque Tp and an r.p.m. ratio e in FIG. 5 will be explained later.
The portion 41 first decides whether or not the throttle valve opening TVO has exceeded a predetermined threshold value TVOth (step 101). When the throttle valve opening TVO has exceeded the threshold value TVOth, the routine proceeds to a step 102, and when not, the routine returns to the step 101 again. At the step 102, the generation portion 41 decides whether or not the acceleration a has exceeded a predetermined threshold value ath. When the acceleration a has exceeded the threshold value ath, the routine proceeds to a step 103, and when not, the routine returns to the step 101 again. At the step 103, the sampling start signal is delivered to the sampling portion 42.
As illustrated FIGS. 6A, 6B and 6C respectively, the sampling portion 42 begins to sample the acceleration a, vehicle speed V and throttle valve opening TVO at predetermined sampling intervals Δt when it has received the sampling start signal from the generation portion 41, in other words, at a point of time tso at which both the threshold values TVOth and ath have already been exceeded.
In this manner, the sampling is started when the throttle valve opening TVO and the acceleration a have exceeded the predetermined threshold values TVOth and ath, respectively. The reason therefor lies in the neural network which is so constructed that the neural vehicle weight estimation portion 43 estimates the vehicle weight W by the use of several signals developed when the vehicle is in such a condition that the accelerator pedal has been depressed to accelerate the vehicle.
In the neural vehicle weight estimation portion 43, the signals of the vehicle speed V, acceleration a and throttle valve opening TVO sampled by the sampling portion 42 enter the input layer as shown in FIG. 3, and the vehicle weight W is thereafter estimated via the intermediate and output layers. As stated before, in the neural vehicle weight estimation portion 43, the synapses are weighted in advance so as to diminish the error E between the estimated vehicle weight We and the real vehicle weight Wre. Therefore, the vehicle weight W delivered from the output layer of the estimation portion 43 has almost no deviation from the actual vehicle weight.
In general, the total running resistance Ftotal of the vehicle differs depending upon the situation of the road, the states of the tyres, etc., and it can be expressed by the sum of a rolling resistance Fr, an air resistance Fa, the gradient resistance F.sub.θ which acts on the vehicle when the vehicle ascends a slope by way of example, and an accelerating resistance Fi which acts on the vehicle when the vehicle is being accelerated. That is, the total running resistance Ftotal can be expressed as indicated by Eq. 1:
Ftotal =Fr +Fa +F.sub.&#952; +Fi      (Eq. 1)
It is accordingly necessary for the evaluation of the gradient resistance F0 to subtract the rolling resistance Fr, air resistance Fa and accelerating resistance Fi from the total running resistance Ftotal as indicated by Eq. 2:
F.sub.&#952; =Ftotal -Fr -Fa -Fi      (Eq. 2)
In this embodiment, therefore, the gradient resistance torque T.sub.θ is evaluated (as illustrated in FIG. 4) by multiplying the turbine torque Tt calculated by the turbine torque calculation portion 50 by the gear ratios r and rD, thereby obtaining the combined resistance torque Ttotal of the axle, and then the accelerating resistance torque Ti and the flatland running resistance torque Tf (=an air resistance torque+a rolling resistance torque) are subtracted from the combined resistance torque Ttotal.
When supplied with the detected throttle valve opening TVO and engine r.p.m. Ne, the engine torque calculation portion 40 evaluates the engine torque Te corresponding to the received throttle valve opening TVO and engine r.p.m. Ne by the use of the engine output characteristics map in which, as shown in FIG. 9, the engine torque Te versus the engine r.p.m. Ne is expressed with the throttle valve opening TVO set as a parameter.
As illustrated in the flow chart of FIG. 12, in the turbine torque calculation portion 50, the torque ratio/capacity coefficient calculation part 51 is supplied with the detected turbine r.p.m. Nt and engine r.p.m. Ne (steps 301 and 302). Then, it evaluates the r.p.m. ratio e (step 303). Subsequently, it evaluates the capacity coefficient τ and torque ratio t of the torque converter corresponding to the evaluated r.p.m. ratio e, by the use of the torque converter characteristics map as shown in FIG. 10 (step 304).
The engine torque Te (=pump torque Tp) can be expressed by Eq. 3:
Te =&#964;�Ne2                              (Eq. 3)
In the multiplier 53, therefore, the term Ne2 evaluated by the multiplier 52 is multiplied by the capacity coefficient τ, whereby the engine torque Te is obtained (step 305). Further, in the multiplier 54, the obtained engine torque Te is multiplied by the torque ratio t evaluated by the torque ratio/capacity coefficient calculation part 51, whereby the turbine torque Tt2 is obtained (step 306).
By the way, in the absence of the turbine r.p.m. sensor 15, the steps 301 and 302 in the series of processing steps for evaluating the turbine torque Tt2 may well be replaced with a step 301a at which the vehicle speed V, engine r.p.m. Ne and gear ratio r are received, and a step 302a at which the turbine r.p.m. Nt is evaluated from the vehicle speed V and the effective radius rw of each tyre.
In this embodiment, not only the torque converter characteristics are utilized for evaluating the turbine torque Tt2 as thus far explained, but also the engine output characteristics stated before are utilized for evaluating the turbine torque Tt1 in order to accurately grasp the turbine torque Tt.
The turbine torque Tt1 is evaluated as illustrated in the flow chart of FIG. 11. More specifically, in the engine torque calculation portion 40, the engine torque Te is evaluated by the processing explained before (steps 201 and 202). Thereafter, the accessory torque Tacc is subtracted from the evaluated engine torque Te in the subtracter 56 (step 203). Finally, the resulting engine torque Te ' is multiplied by the torque ratio t in the multiplier 57 (step 204). Here, the subtraction of the accessory torque Tacc from the engine torque Te is done for the following reason: The component of the accessory torque Tacc is naturally contained in the engine torque Te evaluated using the engine output characteristics. Therefore, when the engine torque Te is directly multiplied by the torque ratio t, the decremental component ascribable to the accessories mounted in the vehicle is contained in the turbine torque to-be-obtained. By the way, in the case where the turbine torque Tt2 is evaluated using the torque converter characteristics, the decremental component ascribable to the mounted accessories is taken into consideration because the turbine r.p.m. Nt is utilized.
The accessory torque Tacc is evaluated as explained below by the accessory torque calculation part 55.
As illustrated in the flow chart of FIG. 13, the accessory torque calculation part 55 decides whether or not the r.p.m. ratio e evaluated by the torque ratio/capacity coefficient calculation part 51 of the turbine torque calculation portion 50 is smaller than 0.8 (step 401). When the r.p.m. ratio e is smaller than 0.8, the routine proceeds to a step 402, and when not, the routine proceeds to a step 404. The step 402 obtains the difference between the turbine torque Tt1 evaluated using the engine output characteristics and the turbine torque Tt2 evaluated using the torque converter characteristics. Further, the next step 403 divides the resulting difference Terr by the torque ratio t, thereby obtaining the accessory torque Tacc. On the other hand, in the case where the step 401 having decided the r.p.m. ratio e to be at least 0.8 is followed by the step 404, the accessory torque Tacc evaluated in the last cycle of the accessory torque calculating operation is directly set.
Alternatively, the accessory torque Tacc can be evaluated as illustrated in the flow chart of FIG. 14. More specifically, the driving torque of the accessory such as an air conditioner is evaluated beforehand, and the turbine torque calculation portion 50 is so constructed that the "ON" signal of the accessory is input to the accessory torque calculation part 55. Thus, the calculation part 55 decides whether or not the air conditioner is turned ON (step 501). When the air conditioner is ON, the accessory torque or air conditioner torque Tac previously obtained is invoked, and it is set as the accessory torque Tacc (step 502), and when not, the accessory torque Tacc is set to 0 (zero) (step 503).
The turbine torque selection part 58 of the turbine torque calculation portion 50 selects either of the turbine torque Tt1 evaluated using the engine output characteristics or the turbine torque Tt2 evaluated using the torque converter characteristics, in accordance with the r.p.m. ratio e evaluated by the torque ratio/capacity coefficient calculation part 51 of the turbine torque calculation portion 50.
In the case of evaluating the turbine torque Tt, it is basically more preferable to utilize the torque converter characteristics. As seen from FIG. 10, however, the capacity coefficient τ changes abruptly when the r.p.m. ratio e enlarges. Therefore, in a case where the r.p.m. ratio e is large to some extent, even the slight error of the r.p.m. ratio e incurs a very great error in the capacity coefficient τ to-be-obtained. Accordingly, in such a case where the engine torque Te is calculated using the capacity coefficient τ at the step 305 (shown in FIG. 12) and where it is used for calculating the turbine torque Tt2 at the step 306, the calculated turbine torque Tt2 cannot be guaranteed to be accurate enough for the large r.p.m. ratio e.
Therefore, when the r.p.m. ratio e is smaller than 0.8, the turbine torque selection part 58 selects the turbine torque Tt2 evaluated using the torque converter characteristics, whereas when the r.p.m. ratio e is at least 0.8, the selection part 58 selects the turbine torque Tt1 evaluated using the engine torque characteristics.
The turbine torque Tt thus obtained is input to the gradient resistance torque calculation portion 60, and is used for the calculation of the gradient resistance torque T.sub.θ.
First, the combined resistance torque Ttotal of the axle is evaluated by multiplying the turbine torque Tt calculated by the turbine torque calculation portion 50 by the gear ratio r of the speed change gear and also by the gear ratio rD of the differential gear (step 601).
Subsequently, the accelerating resistance torque Ti is subtracted from the combined resistance torque Ttotal by the subtracter 64 (step 602).
Here, the accelerating resistance torque Ti can be expressed as indicated by Eq. 4: ##EQU1## where symbol Fi denotes the force of the accelerating resistance, symbol rw the effective radius of each tyre, symbol W the overall weight of the automobile, symbol Wr the weight of the rotating parts of the automobile, and symbol a the acceleration of the vehicle.
That is, the accelerating resistance torque Ti is evaluated by the accelerating resistance torque calculation part 63 by multiplying the sum of the weight Wr of the rotating parts and the estimated vehicle weight W obtained at the vehicle weight estimation means 22 by the effective tyre radius rW obtained beforehand, whereupon the resulting product is multiplied by the acceleration a detected by the acceleration sensor 11.
Subsequently, the gradient resistance torque T.sub.θ is evaluated by the subtracter 65 by further subracting the flatland running resistance torque Tf is from the difference obtained by the subtraction of the accelerating resistance torque Ti from the combined resistance torque Ttotal (step 603). Here, the flatland running resistance torque Tf (=the air resistance torque Ta +the rolling resistance torque Tr) can be expressed as indicated by Eq. (5): ##EQU2## where symbol μ1 denotes an air resistance coefficient, symbol A the projection area of the front of the vehicle, symbol V the vehicle speed, and symbol μ2 a rolling resistance coefficient. In the flatland running resistance torque calculation part 67 for evaluating the flatland running resistance torque Tf, values previously obtained are used as the air resistance coefficient μ1, front projection area A and effective tyre radius rW, the value detected by the vehicle speed sensor 13 is used as the vehicle speed V, and the value calculated by the vehicle weight estimation means 22 is used as the vehicle weight W. In addition, the rolling resistance coefficient μ2 changes depending upon the condition of a road surface, the condition of the tyres, etc. Therefore, the relationships of the rolling resistance coefficient μ2 with the outputs of the various sensors are mapped beforehand, and the coefficient μ2 is obtained using the map.
&#952;�sin &#952;=F.sub.&#952; /W=T.sub.&#952; /(rW.W)(Eq. 7)
Accordingly, the gradient θ is calculated by the divider 71 by dividing the gradient resistance torque T.sub.θ by the effective tyre radius rW and the vehicle weight W (step 605).
By way of example, in a case where the change gear ratio r in the present state is "3", the standard lockup ON line RON4 of 4th speed and the standard upshift line Su3 of 3rd speed→4th speed are respectively selected by the selection means 21 and 24 as shown in FIG. 18A. In the correction means 25 and 26, correction magnitudes α and β indicated by Eqs. 8 and 9 are respectively added to the selected standard lines RON4 and Su3 in order to make the corrections:
&#945;=(&#945;.sub.&#952; +&#945;W).K1(TVO)  (Eq. 8)
&#946;=(&#946;.sub.&#952; &#946;W).K2(TVO)      (Eq. 9)
Here in Eq. 8, symbol α.sub.θ denotes a correction magnitude for the gradient θ, symbol αW a correction magnitude for the vehicle weight W, and symbol K1(TVO) a coefficient which is set for every value of the throttle valve opening TVO. In Eq. 9, symbol β.sub.θ denotes a correction magnitude for the gradient θ, symbol βW a correction magnitude for the vehicle weight W, and symbol K2(TVO) a coefficient which is set every value of the throttle valve opening TVO. Incidentally, regarding the correction magnitudes α.sub.θ and β.sub.θ, values which correspond to the gradient θ are respectively applied by utilizing functions previously stored as shown in FIGS. 19A and 19B. Likewise, regarding the correction magnitudes αW and βW, values which correspond to the estimated vehicle weight W are respectively applied by utilizing functions previously stored as shown in FIGS. 20A and 20B. As illustrated in FIG. 21, the coefficient K.sub.(TVO) is previously given as a function of the throttle valve opening TVO, and it has values of 0 (zero) thru 1 (one) inclusive.
As another example, in a case where the change gear ratio r in the present state is "4", the standard lockup OFF line ROFF4 of 4th speed and the standard downshift line Sd4 of 4th speed→3rd speed are respectively selected by the selection means 21 and 24 as shown in FIG. 18B. In the correction means 25 and 26, correction magnitudes α and β indicated by Eqs. 10 and 11 are respectively added to the selected standard lines ROFF4 and Sd4 in order to make the corrections:
&#945;=(&#945;.sub.&#952; +&#945;W).K3(TVO)  (Eq. 10)
&#946;=(&#946;.sub.&#952; +&#946;W).K4(TVO)     (Eq. 11)
Here, symbols K3(TVO) and K4(TVO) denote coefficients which are set for every value of the throttle valve opening TVO, and which have the relationship shown in FIG. 21 versus the throttle valve opening TVO.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS4393467 *Aug 26, 1980Jul 12, 1983Aisin-Warner Kabushiki KaishaLockup controlling system for variable speed, automatic transmissionUS4523281 *Jul 21, 1982Jun 11, 1985Nippondenso Co., Ltd.Automatic transmission controller for automobilesUS4658676 *Jun 21, 1984Apr 21, 1987Aisin Seiki Kabushiki KaishaTransmission control system for automatic transmissionUS4744269 *Nov 6, 1986May 17, 1988Ford Motor CompanyAutomatic transmission with lockup converter clutch controlsUS4817473 *Mar 11, 1987Apr 4, 1989Ford Motor CompanyHydraulic control valve system for an automatic multiple-speed transmission with a lockup torque converter and electronically operated lockup controlUS4819777 *Apr 9, 1987Apr 11, 1989Toyota Jidosha Kabushiki KaishaSystem for integrally controlling an engine and an automatic transmission having a device for determining engagement of the lockup clutch when a certain time duration elapses after output of an engagement signalUS5048631 *Jun 9, 1989Sep 17, 1991Nissan Motor Company, LimitedSystem and method for automatically controlling vehicle speed to cruise speedUS5231897 *Apr 15, 1991Aug 3, 1993Mitsubishi Denki K.K.Automatic transmission control apparatusUS5267158 *Sep 4, 1992Nov 30, 1993Honda Giken Kogyo Kabushiki KaishaLock-up clutch fuzzy logic control system of vehicle automatic transmissionJPH02212668A * Title not availableJPS61112852A * Title not availableJPS63167161A * Title not available* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS5489248 *Oct 7, 1994Feb 6, 1996Jatco CorporationShift control system for automatic transmissionUS5598336 *Jun 1, 1995Jan 28, 1997Hitachi, Ltd.Automatic transmission control system with variable lockup timingUS5722912 *Aug 29, 1996Mar 3, 1998Honda Giken Kogyo Kabushiki KaishaLock-up control system for automatic transmissionsUS5976055 *Apr 10, 1998Nov 2, 1999Mazda Motor CorporationLockup force control apparatus for fluid coupling in vehicle with automatic transmissionUS6167357 *Apr 23, 1998Dec 26, 2000Cummins Engine Company, Inc.Recursive vehicle mass estimationUS6231480 *May 8, 1998May 15, 2001Mazda Motor CorporationLockup control system for fluid coupling of automatic transmissionUS6314357Sep 30, 1998Nov 6, 2001Honda Giken Kogyo Kabushiki KaishaLock-up control deviceUS6438510Dec 22, 2000Aug 20, 2002Cummins Engine Company, Inc.Recursive vehicle mass estimation systemUS6446024Jun 17, 1998Sep 3, 2002Robert Bosch GmbhProcess and device for determining a vehicle's massUS7966115 *Jun 21, 2011Cummins Inc.System and method for controlling transmission shift points based on vehicle weightUS8650833 *Jun 13, 2013Feb 18, 2014Ross Manufacturing, LlcMethod for installing a roof ventUS8954246Dec 14, 2012Feb 10, 2015Caterpillar Inc.Grade and payload estimate-based transmission gear selectionUS9052013Dec 14, 2012Jun 9, 2015Caterpillar Inc.Grade and payload based transmission gear selection strategyUS20040167705 *Feb 17, 2004Aug 26, 2004Volvo Lastvagnar AbMethod For Estimating The Mass Of A Vehicle Which Is Being Driven On A Road With A Varying Gradient And Method For Estimating The Gradient Of The Road Upon Which The Vehicle Is Being DrivenUS20040236439 *May 20, 2004Nov 25, 2004Samson AktiengesellschaftMethod and device to prevent a critical operating state of a control deviceUS20070271017 *May 18, 2006Nov 22, 2007Farzad SamieWeight dependent trailering switchUS20090036267 *Aug 2, 2007Feb 5, 2009Bellinger Steven MSystem and Method for Controlling Transmission Shift Points Based on Vehicle WeightUS20110172877 *Jul 14, 2011Dourra Hussein AMass, drag coefficient and inclination determination using accelerometer sensorUS20130166164 *Dec 17, 2012Jun 27, 2013GM Global Technology Operations LLCGear selection device for a motor vehicleUS20140149017 *Nov 29, 2012May 29, 2014Ford Global Technologies, LlcSystem and method for improving vehicle performanceDE19717355B4 *Apr 24, 1997Apr 5, 2007Toyota Jidosha Kabushiki Kaisha, ToyotaFahrzeugsteuervorrichtung f�r eine Schlupfsteuerung einer �berbr�ckungskupplung w�hrend einer Verz�gerung und f�r ein automatisches Herunterschalten eines Getriebes w�hrend einer BergabfahrtEP0760443A2 *Aug 29, 1996Mar 5, 1997Honda Giken Kogyo Kabushiki KaishaLock-up control system for automatic transmissionsEP0872668A1 *Apr 14, 1998Oct 21, 1998Mazda Motor CorporationLockup force control apparatus for fluid coupling in vehicle with automatic transmissionEP0878645A2 *May 12, 1998Nov 18, 1998Mazda Motor CorporationLockup control system for fluid coupling of automatic transmissionEP0907043A1 *Oct 1, 1998Apr 7, 1999Honda Giken Kogyo Kabushiki KaishaTorque converter lock-up control deviceEP1106872A1 *Dec 1, 2000Jun 13, 2001Peugeot Citroen AutomobilesMethod of controlling an automatic transmission according to road slopeWO1999002947A1 *Jun 17, 1998Jan 21, 1999Robert Bosch GmbhProcess and device for determining a vehicle's massWO2002055909A1 *Jan 9, 2002Jul 18, 2002Siemens AktiengesellschaftMethod for controlling the gearbox of a motor vehicleWO2003016837A1 *Aug 19, 2002Feb 27, 2003Volvo Lastvagnar AbMethod for estimation of the mass of a vehicle which is driven on a road with varying inclination and method for estimation of road inclinationWO2011085060A1 *Jan 6, 2011Jul 14, 2011Chrysler Group LlcMass, drag coefficient and inclination determination using accelerometer sensorWO2012134377A1 *Mar 26, 2012Oct 4, 2012Scania Cv AbEstimation of weight for a vehicle* Cited by examinerClassifications U.S. Classification701/65, 477/120, 477/148, 701/66, 192/3.3, 477/63, 192/3.29, 192/3.54International ClassificationF16H59/44, F16H61/02, F16H59/74, F16H61/00, F16H59/14, F16H61/08, F16H59/52, F16H61/10, F16H61/14, F16H59/66, B60W50/00Cooperative ClassificationY10T477/6351, Y10T477/693754, Y10T477/692, Y10T477/60, Y10S477/90, Y10S706/905, F16H2059/142, F16H59/66, F16H59/14, F16H61/143, B60W2510/105, F16H61/0213, F16H2059/148, F16H59/74, F16H59/52, F16H2061/0096, B60W2050/0057, F16H2061/0081, F16H59/44, B60T2250/02, B60W2550/142, F16H2059/663European ClassificationF16H61/14E, F16H59/14Legal EventsDateCodeEventDescriptionAug 12, 1993ASAssignmentOwner name: HITACHI, LTD., JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KUME, MASAYUKI;ISHII, JUNICHI;REEL/FRAME:007467/0007Effective date: 19930726Owner name: HITACHI, LTD., JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KUME, MASAYUKI;ISHII, JUNICHI;REEL/FRAME:006658/0736Effective date: 19930726Jan 4, 1999FPAYFee paymentYear of fee payment: 4Dec 30, 2002FPAYFee paymentYear of fee payment: 8Dec 21, 2006FPAYFee paymentYear of fee payment: 12RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services