Abstract:
A method for self configuring automated mechanical transmissions (AMT) and electronic control units (ECU) ensures compatibility therebetween. The method comprehends undertaking a program or subroutine when the vehicle is first powered up which moves the shift operators into a predetermined position. The shift operators include full stroke sensors. Depending upon differences between the commanded shift pattern and the actual shift pattern of the transmission, the specific type of transmission, for example, a twelve speed or a sixteen speed, can be determined.

Description:
BACKGROUND OF THE INVENTION 
   The invention relates generally to a method for self-configuring automated mechanical truck transmissions and controller and more particularly to a method for self-configuring and checking compatibility between automated mechanical truck transmissions and electronic controllers. 
   Initially, heavy duty truck transmissions included manually, i.e., operator adjusted, devices including a hand operated gear shift and a foot operated master friction clutch. This operational configuration remained essentially unchanged for many years after the advent of motor vehicles. 
   During the last few decades, manual, i.e., operator control, of the gear shift and master clutch of heavy duty vehicles such as trucks has become increasingly automated to the point today where an electronic control unit (ECU) provided with data from various speed and position sensors controls selection of gear ratios in the main transmission and auxiliary units such as splitters and planetary gear units as well as engagement and disengagement of the master friction clutch. Both the automated transmissions and electronic control units have become increasingly sophisticated during this time. 
   Modern day electronic control units are particularly complex memory and processing units which may be flashed with current software subroutines, lookup tables and the like which are then mated with an appropriate, compatible transmission. It is, of course, desirable to properly mate such software and hardware in order to ensure compatibility therebetween. It is also desirable to detect and ensure this compatibility even before the vehicle is mechanically powered up and driven. This is especially necessary since there is often little physical evidence or manner of determining the software loaded into an electronic controller by any reasonable, physical or electrical examination or test. 
   The present invention addresses this challenge and provides a detection subroutine which provides information to the electronic controller regarding an identifiable variable of the transmission which indicates its particular type and thus confirms or does not confirm compatibility between the electronic control unit and its software and the transmission. 
   SUMMARY OF THE INVENTION 
   An apparatus and method for self configuring automated mechanical transmissions (AMT) and electronic control units (ECU) ensures compatibility therebetween. The method comprehends undertaking a program or subroutine when the vehicle is first powered up which moves the shift rail operators through a predetermined series of positions. The shift actuators include full stroke sensors which are capable of detecting motion in the XY plane of the main gear box operators. Depending upon differences between the commanded shift pattern and the actual shift pattern of the particular transmission being checked, the specific type of transmission, for example, a twelve speed or a sixteen speed can be determined. If the electronic controller and transmission are not compatible, i.e. the transmission in a twelve speed and the electric controller is a sixteen speed, a fault or shutdown signal is generated. 
   Thus it is an object of the present invention to provide a method for ensuring compatibility between an electronic control unit and automatic mechanical transmission. 
   It is a still further object of the present invention to provide a method for determining the identity or configuration of a motor vehicle transmission by commanding certain gear shifts and monitoring the activity of the transmission shifts. 
   It is a still further object of the present invention to provide a method for determining the configuration of an automated mechanical transmission by providing software which commands certain shifts which reveal the configuration and identify of the transmission. 
   Further objects and advantages of the present invention will become apparent by reference to the following description of the preferred embodiment and appended drawings wherein like reference numbers refer to the same component, element or feature. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a diagrammatic view of a typical twelve or sixteen speed heavy duty transmission and electronic control unit incorporating the present invention; 
       FIG. 2  is a diagrammatic perspective view of a shift operator assembly of an automated mechanical transmission incorporating the present invention; 
       FIG. 3  is a full, sectional view of the main gear box engage operator of an automated mechanical transmission incorporating the present invention taken along line  3 - 3  of  FIG. 2 ; 
       FIG. 4  is the shift pattern of a typical twelve speed transmission incorporating the present invention; 
       FIG. 5  is the shift pattern of a typical sixteen speed transmission incorporating the present invention; 
       FIG. 6  is an alternative shift pattern of a twelve speed transmission incorporating the present invention; 
       FIG. 7  is an alternative shift pattern of a sixteen speed transmission incorporating the present invention; and 
       FIG. 8  is a computer software flowchart of the automated mechanical transmission self configuration method according to the present invention. 
   

   DESCRIPTION OF PREFERRED EMBODIMENT 
   Referring now to  FIG. 1 , an automated mechanical transmission incorporating the present invention is diagrammatically illustrated and generally designated by the reference number  8 . The automated mechanical transmission  8  includes a splitter or two speed gear box  10  which is driven by the master friction clutch (not illustrated) and which drives a main or primary three or four (forward) speed gear box  12  which, in turn, drives a planetary two speed gear box  14 . A housing receives, mounts and protects these aforementioned gear boxes  10 ,  12  and  14 . 
   An electronic control unit (ECU)  16  includes software, lookup tables, memory and the like, receives data from the vehicle operator and various vehicle and drive train sensors and provides control signals to, inter alia, a shift operator assembly  18 . 
   Referring now to  FIG. 2 , the shift operator assembly  18  includes a splitter shift assembly  20  having a first longitudinally oriented cylinder  22  which receives a first double acting piston and shift rod assembly  24  to which is secured a splitter shift fork  26 . The splitter shift fork  26  is conventional and defines two arms  28  which include suitably configured engagement structures  32  which engage and translate gears of the splitter or first gear box  10  of the transmission  8 . The first piston and shift rod assembly  24  translates between a forward, engaged position a center or intermediate neutral position and a rearward, engaged position. A first linear sensor or transducer  34  associated with the first cylinder  22  provides an output representing the current or real time position of the first piston and shift rod assembly  24 . 
   The shift operator assembly  18  also includes a planetary shift assembly  40  which includes a second longitudinally oriented cylinder  42  which receives a second double acting piston and shift rod assembly  44  which terminates in a planetary shift fork  46 . Once again, the shift fork  46  is conventional and includes a pair of arms  48  which terminate in gear engaging structures  52  which change the gear speed ratio of the planetary two speed gear box  14  disposed at the rear of the transmission  8 . The second piston and shift rod assembly  44  translate between a forward, engaged position, a center or intermediate neutral position and a rearward, engaged position. A second linear sensor or transducer  54  associated with the second cylinder  42  provides a second output representing the current or real time position of the second piston and shift rod assembly  44 . 
   Intermediate the splitter shift assembly  20  and the planetary shift assembly  40  is an engage or main gear box shift assembly  60 . The engage or main gear box shift assembly  60  likewise includes a third cylinder  62  which receives a third double acting piston and shift rod assembly  64  which is translated axially between a forward, engaged position, a center or intermediate neutral position, and a rearward, engaged position. Axial translation of the third piston and shift rod assembly  64  similarly translates a main shift fork assembly  66 . The main shift fork assembly  66  includes a forward and rearward pair of shift forks  68  and  72  which likewise include gear engaging structures  74 . A third linear sensor or transducer  76  associated with the third cylinder  62  provides a third output representing the current or real time position of the third piston and shift rod assembly  64 . 
   Referring now to  FIGS. 2 and 3 , in addition to axial translation, the third piston and shift rod assembly  64  are capable of limited rotation about its longitudinal axis. Such rotation is achieved by the action of an select shift assembly  80 . The select shift assembly  80  includes a fourth cylinder  82  transversely oriented which receives a fourth transversely oriented piston and shift rod assembly  84  which terminates in a U-shaped operator or actuator block  86  which defines a slot  88 . The slot is oriented longitudinally and moves transversely relative to the third piston and shift rod assembly  64 . Received within the slot  88  of the block  86  is an actuating or register pin  92  which extends radially from the third piston and shift rod assembly  64 . Accordingly, as the fourth piston and shift rod assembly  84  as well as the actuator block  86  translate along their axis, motion of the actuating pin  92  within the slot  88  causes limited rotation of the third piston and shift rod assembly  64  about its longitudinal axis. The fourth piston and shift rod assembly  84  translate between a left position, a center or intermediate position and a right position. A fourth linear sensor or transducer  96  associated with the fourth cylinder  82  provides a fourth output representing the current or real time position of the fourth piston and shift rod assembly  84 . The three positions of the select shift assembly  80  or engage coupled with the forward, center and rearward positions of the main shift assembly  60 , provide or are capable of providing nine distinct positions. Suitable detent mechanisms  98  provide longitudinally detented positions along the third piston and shift rod assembly  64  as well as the other shift rod assemblies  24  and  44 . 
   Turning now to  FIG. 4 , a typical shift pattern for a twelve speed truck transmission is schematically illustrated and designated by the reference number  100 . The shift pattern  100  of the main shift assembly  60  and the select shift assembly  80  is defined as an “H”. At the upper left corner of the shift pattern  100  is reverse gear, which is engaged when the main or engage shift assembly  60  is in its forward position and the select shift assembly  80  is in its left position. Selection of reverse high (RH) or reverse low (RL) is achieved by selecting between the two gear ratios provided by the splitter shift assembly  20 . First gear and related gears (2 nd , 7 th  and 8 th ) are achieved (from reverse) by no action of the select shift assembly  80  and moving the main or engage shift assembly  60  to its rear position. Neutral is achieved when both of these shift assemblies are in or are moved to their centered positions. Third gear and related gears (4 th , 9 th  and 10 th ) are achieved (from the first gear position) when the select shift assembly  80  retracts to the right and the main or engage shift assembly  60  is moved forward. Fifth gear and related gears (6 th , 11 th  and 12 th ) are achieved from the third and related gear position without action of the select shift assembly  80  while the main or engage shift assembly  60  moves to the rear. Selection of adjacent gear ratios in a given position of the main gear box  12  such as 1 st  and 2 nd  gear, 9 th  and 10 th  or 5 th  and 6 th  will typically be achieved by operation of the splitter shift assembly  20 . 
   The conventional twelve speed transmission shift pattern  100  illustrated in  FIG. 4  should be contrasted with the conventional sixteen speed transmission shift pattern  102  illustrated in  FIG. 5 . Here, in the upper left corner of the shift pattern is first gear and related gears (2 nd , 9 th  and 10 th ). To the lower left of the shift pattern  102  is third and related gears (4 th , 11 th  and 12 th ). In the upper right corner of the shift pattern  102  is fifth and related gears (6 th , 13 th  and 14 th ) and in the lower right corner of the shift pattern  102  is seventh and related gears (8 th , 15 th  and 16 th ). Both high and low reverse gears are engaged by moving the select shift assembly  80  to its center position and then moving the main shift assembly  60  to its rear position. 
   Turning now to  FIG. 6 , an alternative shift pattern for a twelve speed truck transmission is schematically illustrated and designated by the reference number  104 . The shift pattern  104  of the main shift assembly  60  and the select shift assembly  80  is defined as an “H”. At the upper left corner of the shift pattern  104  is reverse gear, which is engaged when the main or engage shift assembly  60  is in its forward position and the select shift assembly  80  is in its left position. First gear and related gears (4 th , 7 th  and 11 th ) are achieved (from reverse) by no action of the select shift assembly  80  and moving the main or engage shift assembly  60  to its rear position. Neutral is achieved when both of these shift assemblies are in their centered positions. Third gear and related gears (5 th , 8 th  and 11 th ) are achieved (from first gear) when the select shift assembly  80  retracts to the right and the main or engage shift assembly  60  is moved forward. Third gear and related gears (6 th , 9 th  and 12 th ) are achieved (from second gear) without action of the select shift assembly  80  while the main or engage shift assembly  60  moves to the rear. 
   The alternative twelve speed transmission shift pattern  104  illustrated in  FIG. 6  should be contrasted with an alternative sixteen speed transmission shift pattern  106  illustrated in  FIG. 7 . Here, in the upper left corner of the shift pattern is first gear and related gears (5 th , 9 th  and 13 th ). To the lower left of the shift pattern  106  is third and related gears (6 th , 10 th  and 14 th ). In the upper right corner of the shift pattern  106  is fifth and related gears (7 th , 11 th  and 15 th ) and in the lower right corner of the shift pattern  106  is seventh and related gears (8 th , 12 th  and 16 th ). Reverse is engaged by moving the select shift assembly  80  to its center position and then moving the main shift assembly  60  to its rear position. 
   Comparison of these four shift patterns reveals that whereas the upper left corner of the twelve speed shift patterns  100  and  104  is reverse gear, the upper left position of the sixteen speed transmission shift patterns  102  and  106  is first gear. 
   The consequence of these situations is that if an electronic controller configured and intended for use with a twelve speed transmission is inadvertently installed with a sixteen speed transmission first gear will be engaged when reverse was commanded and intended. Given the opposite situation (a sixteen speed controller installed with a twelve speed transmission) when first gear is requested, reverse will be selected. Even during initial power up and test of the vehicle, such unexpected motion in a direction opposite that intended and expected is to be avoided. The present invention cooperates with the automated shift assembly  18  to detect, the first time the vehicle is powered up, the shift pattern of the transmission  8  to ascertain that the electronic control unit  16  for a twelve or sixteen speed transmission is properly mated to a twelve or sixteen speed transmission. 
   This self-check or self-configuration is achieved by detecting the physically different shift pattern  102  of the sixteen speed transmission which includes a center, reverse position whereas a twelve speed transmission shift pattern  100  defines a conventional four cornered “H” pattern. In fact, determination of the difference between a twelve speed or a sixteen speed transmission is based upon the fact that center, rearward motion of the main (engage) and select shift assemblies  60  and  80  will engage reverse in a sixteen speed transmission and thus the operators will experience or achieve only a finite amount of travel which selects reverse gear. By contrast, in a twelve speed transmission, if the shift assemblies  60  and  80  are centered and then moved rearward, there will be no feature or structure which will impede motion and the main or engage shift assembly  60  will translate to the full extent of its travel, thereby evidencing that no reverse gear may be or was engaged and thereby identifying the transmission as a twelve speed transmission. 
   It will be appreciated that this invention may be utilized in any type of mechanical device wherein pneumatic, hydraulic or electric actuators associated with respective linear transducers or sensors are utilized to translate components or structures along one or multiple axes. When travel along a certain axis or combination of axes exceeds that which is possible with a given component or type of component, such additional motion may therefore be interpreted as representing another component as well as a fault of failure of the given component. 
   Referring now to  FIG. 6 , a flow chart for a computer self-configuration or identification program or software  110  incorporating the present invention is illustrated. The program  110  commences with a start instruction  112  which initializes and clears any data registers. The program  110  then moves to a decision point  114  which inquires whether this is the initial system power up, that is, whether this is the first time the vehicle and specifically the transmission and electronic control unit. If it is not, the decision point  114  is exited at NO and the program terminates at end point  130 . If this is the initial system power up, the decision point  114  is exited YES and the program  110  moves to a process step  116  which commences execution of the transmission and shift assembly self check. The first step of the self check is to move all four operators, the operators for the splitter, the planetary and the main or engage and select cylinders to neutral, i.e., their center positions. Alternatively, at least the engage or main and select shift assemblies  60  and  80  must be moved to neutral as the self-configuration or identification program  110  does not involve action or positions of the splitter or planetary shift assemblies  20  and  40 . 
   Next, the program  110  moves to a process step  120  which commences motion of the main or engage shift assembly  60  toward the reverse gear of a sixteen speed transmission as illustrated is  FIG. 5 . After the main or engage shift assembly  60  has engaged reverse or while such motion is occurring, the process step  122  may be undertaken which reads the output of the third transducer  76  of the main or engage shift assembly  60  to determine the extent of travel of the engage or main piston and shift rod assembly  64 . Next, a decision point  124  is entered which inquires whether the travel of the third or engage transducer  76  (and the main piston and shift rod assembly  64 ) was greater than that expected to place a sixteen speed transmission into reverse gear. 
   If the travel is greater than that associated with placing a sixteen speed transmission in reverse gear, the decision point  124  is exited at YES and the program  110  identifies or sets a flag that designates the transmission  8  with which the electronic control unit  16  is associated as a twelve speed transmission. The program  110  now moves to a decision point  128  which inquires whether the electronic control unit  16  with which the present transmission  8  is associated is a twelve speed controller. If it is, the decision point  128  is exited at YES and the program  110  terminates at the step  130 . If the electronic control unit  16  is not a twelve speed controller, the decision point  128  is exited at NO and a process step  132  defaults and/or stops the self-check program  110  as there is an incompatibility between the transmission  8  and the electronic control unit  16 . 
   Alternatively, the decision point  124  is exited at NO if the translation of the third or engage transducer  76  is less than or equal to the travel required to achieve reverse gear. In this instance, the transmission  8  is a sixteen speed transmission and the program  110  enters a process step  134  which identifies or sets a flag with the electronic control unit  16  which indicates that the transmission  8  is a sixteen speed transmission. Then the program  110  moves to a decision point  136  which inquires whether the electronic control unit  16  associated with the particular transmission  8  undergoing the self-check is a sixteen speed control unit. If it is, there is compatibility between the two units, the decision point  136  is exited at YES and the program  110  terminates at the end point  130 . If the electronic control unit  16  is not a sixteen speed controller, the decision point  136  is exited at NO and the program  110  defaults and/or stops at the process step  132 . A fault light or other indicator (not illustrated) of the incompatibility may be illuminated or provided at the process step  132  or data may be provided in some other fashion such as a test printout to indicate the incompatibility between the transmission  8  and the electronic control unit  16 . 
   Alternatively, if the electronic control unit  16  has sufficient memory and computing capability that it may operate with both a twelve speed transmission and a sixteen speed transmission, the flags set in the process steps  126  and  134  may be read by the electronic control unit  16 . If the flag for a twelve speed transmission is set, all subsequent shift commands will be based upon the shift pattern  100  illustrated in  FIG. 4  relating to a twelve speed transmission. If the flag indicating a sixteen speed transmission is set in the process step  134 , all subsequent shift commands are then based upon and utilize the shift pattern  102  appearing in  FIG. 5 . 
   The foregoing disclosure is the best mode devised by the inventors for practicing this invention. It is apparent, however, that methods and apparatus incorporating modifications and variations will be obvious to one skilled in the art of automated mechanical transmissions and electronic controllers. Inasmuch as the foregoing disclosure is intended to enable one skilled in the pertinent art to practice the instant invention, it should not be construed to be limited thereby but should be construed to include such aforementioned obvious variations and be limited only by the spirit and scope of the following claims.