Patent Publication Number: US-2011049974-A1

Title: Methods and systems for braking different axles of a vehicle using a deceleration value

Description:
TECHNICAL FIELD 
     The present invention generally relates to the field of vehicles and, more specifically, to methods and systems for controlling braking of vehicles. 
     BACKGROUND OF THE INVENTION 
     Automobiles and various other vehicles include braking systems for reducing vehicle speed or bringing the vehicle to a stop. Such braking systems generally include a controller that provides braking pressure to braking calipers on one or both axles of the vehicle to produce braking torque for the vehicle. For example, in a regenerative braking system, a relatively greater amount of hydraulic or other braking pressure is generally provided for a non-regenerative braking axle, while a relatively lesser amount (if any) of hydraulic or other braking pressure is generally provided for a regenerative braking axle. However, in certain situations, for example when there is a pressure change in the regenerative axle results in fluctuations in boost pressure, a less than ideal driving experience, for example with non-linear decelerations, can result. 
     Accordingly, it is desirable to provide an improved method for controlling braking for a vehicle that provides braking pressure to different axles of the vehicle, such as a regenerative braking axles and a non-regenerative braking axle, in an improved manner. It is also desirable to provide an improved system for such controlling of braking for a vehicle that provides braking pressure to different axles of the vehicle in an improved manner. Furthermore, other desirable features and characteristics of the present invention will be apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. 
     SUMMARY OF THE INVENTION 
     In accordance with an exemplary embodiment of the present invention, a method for controlling braking of a vehicle having a first axle and a second axle is provided. The method comprises the steps of obtaining a deceleration value pertaining to an input from a driver of the vehicle, braking the first axle with a first pressure, braking the second axle with a second pressure that is substantially equal to the first pressure if the deceleration value has not exceeded a predetermined threshold, and braking the second axle with a third pressure that is greater than the first pressure if the deceleration value has exceeded the predetermined threshold. 
     In accordance with another exemplary embodiment of the present invention, a method for controlling braking of a vehicle having a regenerative braking axle and a non-regenerative braking axle is provided. The method comprises the steps of obtaining a deceleration value pertaining to an input from a driver of the vehicle, braking the regenerative braking axle and the non-regenerative braking axle using single channel blending provided that the deceleration value is less than or equal to a predetermined threshold, and braking the regenerative braking axle and the non-regenerative braking axle using dual channel blending if the deceleration value is greater than the predetermined threshold. 
     In accordance with a further exemplary embodiment of the present invention, a system for controlling braking of a vehicle having a regenerative braking axle and a non-regenerative braking axle is provided. The system comprises a sensor and a processor. The sensor is configured to detect a request corresponding to a requested braking torque. The processor is coupled to the sensor. The processor is configured to facilitate determining a deceleration pertaining to the vehicle based on the requested braking torque, braking the regenerative braking axle and the non-regenerative braking axle using single channel blending provided that the deceleration value is less than or equal to a predetermined threshold, and braking the regenerative braking axle and the non-regenerative braking axle using dual channel blending if the deceleration value is greater than the predetermined threshold. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: 
         FIG. 1  is a functional block diagram of a braking system for a vehicle, such as an automobile, in accordance with an exemplary embodiment of the present invention; 
         FIG. 2  is a flowchart of a process for controlling braking and for apportioning braking pressure to different axles of the vehicle in a vehicle, such as an automobile, and that can be utilized in connection with the brake controller of  FIG. 1 , in accordance with an exemplary embodiment of the present invention; and 
         FIG. 3  is a depiction of exemplary graphical representation of various parameters pertaining to the brake controller of  FIG. 1  and the process of  FIG. 2  for an exemplary scenario in which the vehicle is being operated, in accordance with an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description of the invention is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description of the invention. 
       FIG. 1  is a block diagram of an exemplary braking system  100  for use in a brake-by-wire system of vehicle, such as an automobile. In a preferred embodiment, the vehicle comprises an automobile, such as a sedan, a sport utility vehicle, a van, or a truck. However, the type of vehicle may vary in different embodiments of the present invention. 
     As depicted in  FIG. 1 , the braking system  100  includes a brake pedal  102 , a brake controller  104 , and a plurality of brake units  106 . The braking system  100  is used in connection with a first axle  130  and a second axle  132 . Each of the first and second axles  130 ,  132  has one or more wheels  108  of the vehicle disposed thereon. Certain of the brake units  106  are disposed along a first axle  130  of the vehicle along with certain of the wheels  108 , and certain other of the brake units  106  are disposed along a second axle  132  of the vehicle along with certain other of the wheels  108 . In a preferred embodiment, the first axle  130  is a regenerative braking axle, and the second axle  132  is a non-regenerative braking axle  132 . Also in one preferred embodiment, the first axle  130  comprises a front axle, and the second axle  132  comprises a rear axle. 
     The brake pedal  102  provides an interface between an operator of a vehicle and a braking system or a portion thereof, such as the braking system  100 , which is used to slow or stop the vehicle. To initiate the braking system  100 , an operator would typically use his or her foot to apply a force to the brake pedal  102  to move the brake pedal  102  in a generally downward direction. In one preferred embodiment the braking system  100  is an electro-hydraulic system. In another preferred embodiment, the braking system  100  is a hydraulic system. 
     The brake controller  104  is coupled between the brake pedal  102  and the brake units  106 , and the first and second axles  130 ,  132 . Specifically, the brake controller  104  monitors the driver&#39;s engagement of the brake pedal  102  and controls braking of the vehicle to apply appropriate amounts of braking pressure to the first axle  130  and to the second axle  132  of the braking system  100  via braking commends sent to the brake units  106  by the brake controller  104  along the first and second axles  130 ,  132 . 
     In the depicted embodiment, the brake controller  104  comprises one or more brake pedal sensors  110  and a computer system  112 . In certain embodiments, the brake controller  104  may be separate from the brake pedal sensors  110 , among other possible variations. In addition, it will be appreciated that the brake controller  104  may otherwise differ from the embodiment depicted in  FIG. 1 , for example in that the brake controller  104  may be coupled to or may otherwise utilize one or more remote computer systems and/or other control systems. 
     The brake pedal sensors  110  are coupled between the brake pedal  102  and the computer system  112 . Specifically, in accordance with various preferred embodiments, the brake pedal sensors  110  preferably include one or more brake pedal force sensors and/or one or more brake pedal travel sensors. The number of brake pedal sensors  110  may vary. For example, in certain embodiments, the brake controller  104  may include a single brake pedal sensor  110 . In various other embodiments, the brake controller  104  may include any number of brake pedal sensors  110 . 
     The brake pedal travel sensors, if any, of the brake pedal sensors  110  provide an indication of how far the brake pedal  102  has traveled, which is also known as brake pedal travel, when the operator applies force to the brake pedal  102 . In one exemplary embodiment, brake pedal travel can be determined by how far an input rod in a brake master cylinder has moved. 
     The brake pedal force sensors, if any, of the brake pedal sensors  110  determine how much force the operator of braking system  100  is applying to the brake pedal  102 , which is also known as brake pedal force. In one exemplary embodiment, such a brake pedal force sensor, if any, may include a hydraulic pressure emulator and/or a pressure transducer, and the brake pedal force can be determined by measuring hydraulic pressure in a master cylinder of the braking system  100 . 
     Regardless of the particular types of brake pedal sensors  110 , the brake pedal sensors  110  detect one or more values (such as brake pedal travel and/or brake pedal force) pertaining to the drivers&#39; engagement of the brake pedal  102 . The brake pedal sensors  110  also provide signals or information pertaining to the detected values pertaining to the driver&#39;s engagement of the brake pedal  102  to the computer system  112  for processing by the computer system  112 . 
     In the depicted embodiment, the computer system  112  is coupled between the brake pedal sensors  110 , the brake units  106 , and the first and second axles  130 ,  132 . The computer system  112  receives the signals or information pertaining to the drivers&#39; engagement of the brake pedal  102  from the brake pedal sensors  110 . The computer system  112  further processes these signals or information in order to control braking of the vehicle and apply appropriate amounts of braking pressure to the first axle  130  and to the second axle  132  of the braking system  100  via braking commends sent to the brake units  106  by the computer system  112  along the first and second axles  130 ,  132 , for improved braking performance and/or an improved experience for the driver of the vehicle. In a preferred embodiment, these and other steps are conducted in accordance with the process  200  depicted in  FIG. 2  and described further below in connection therewith. 
     In the depicted embodiment, the computer system  112  includes a processor  114 , a memory  118 , an interface  116 , a storage device  124 , and a bus  126 . The processor  114  performs the computation and control functions of the computer system  112  and the brake controller  104 , and may comprise any type of processor or multiple processors, single integrated circuits such as a microprocessor, or any suitable number of integrated circuit devices and/or circuit boards working in cooperation to accomplish the functions of a processing unit. During operation, the processor  114  executes one or more programs  120  contained within the memory  118  and, as such, controls the general operation of the brake controller  104  and the computer system  112 . 
     The memory  118  can be any type of suitable memory. This would include the various types of dynamic random access memory (DRAM) such as SDRAM, the various types of static RAM (SRAM), and the various types of non-volatile memory (PROM, EPROM, and flash). The bus  126  serves to transmit programs, data, status and other information or signals between the various components of the computer system  112 . In a preferred embodiment, the memory  118  stores the above-referenced program  120  along with various threshold values  122  that are used in controlling the braking and apportioning braking pressure to the first and second axles  130 ,  132  in accordance with steps of the process  200  depicted in  FIG. 2  and described further below in connection therewith. 
     The interface  116  allows communication to the computer system  112 , for example from a system driver and/or another computer system, and can be implemented using any suitable method and apparatus. It can include one or more network interfaces to communicate with other systems or components. The interface  116  may also include one or more network interfaces to communicate with technicians, and/or one or more storage interfaces to connect to storage apparatuses, such as the storage device  124 . 
     The storage device  124  can be any suitable type of storage apparatus, including direct access storage devices such as hard disk drives, flash systems, floppy disk drives and optical disk drives. In one exemplary embodiment, the storage device  124  comprises a program product from which memory  118  can receive a program  120  that executes one or more embodiments of one or more processes of the present invention, such as the process  200  of  FIG. 2  or portions thereof. In another exemplary embodiment, the program product may be directly stored in and/or otherwise accessed by the memory  118  and/or a disk such as that referenced below. 
     The bus  126  can be any suitable physical or logical means of connecting computer systems and components. This includes, but is not limited to, direct hard-wired connections, fiber optics, infrared and wireless bus technologies. During operation, the program  120  is stored in the memory  118  and executed by the processor  114 . 
     It will be appreciated that while this exemplary embodiment is described in the context of a fully functioning computer system, those skilled in the art will recognize that the mechanisms of the present invention are capable of being distributed as a program product in a variety of forms, and that the present invention applies equally regardless of the particular type of computer-readable signal bearing media used to carry out the distribution. Examples of signal bearing media include: recordable media such as floppy disks, hard drives, memory cards and optical disks, and transmission media such as digital and analog communication links. It will similarly be appreciated that the computer system  112  may also otherwise differ from the embodiment depicted in  FIG. 1 , for example in that the computer system  112  may be coupled to or may otherwise utilize one or more remote computer systems and/or other control systems. 
     The brake units  106  are coupled between the brake controller  104  and the wheels  108 . In the depicted embodiment, the brake units  106  are disposed along the first axle  130  and are coupled to certain wheels  108  on the first axle  130 , and other of the brake units  106  are disposed along the second axle  132  and are coupled to other wheels of the second axle  132 . The brake units  106  receive the braking commands from the brake controller  104 , and are controlled thereby accordingly. 
     The brake units  106  can include any number of different types of devices that, upon receipt of braking commands, can apply the proper braking torque as received from the brake controller  104 . For example, in an electro-hydraulic system, the brake units  106  can comprise an actuator that can generate hydraulic pressure that can cause brake calipers to be applied to a brake disk to induce friction to stop a vehicle. Alternatively, in an electro-mechanical brake-by-wire system, the brake units  106  can comprise a wheel torque-generating device that operates as a vehicle brake. The brake units  106  can also be regenerative braking devices, in which case the brake units  106 , when applied, at least facilitate conversion of kinetic energy into electrical energy. 
       FIG. 2  is a flowchart of a process  200  for controlling braking in a vehicle and for apportioning braking pressure to different axles of the vehicle, in accordance with an exemplary embodiment of the present invention. The process  200  can be implemented in connection with the braking system  100  of  FIG. 1 , the brake controller  104  and/or the computer system  112  of  FIG. 1 , and/or program products utilized therewith, in accordance with an exemplary embodiment of the present invention. The process  200  will also be described below in connection with  FIG. 3 , which depicts a graphical representation  300  of various parameters pertaining to the process  200  in accordance with one exemplary embodiment of the present invention and with operation of the vehicle in one exemplary scenario. 
     As depicted in  FIG. 2 , the process  200  begins with the step of receiving one or more braking requests (step  202 ). The braking requests preferably pertain to values pertaining to engagement of the brake pedal  102  by a driver of the vehicle. In certain preferred embodiment, the braking requests pertain to values of brake pedal travel and/or brake pedal force as obtained by the brake pedal sensors  110  of  FIG. 1  and provided to the computer system  112  of  FIG. 1 . Also in a preferred embodiment, the braking requests are received and obtained, preferably continually, at different points or periods in time throughout a braking event for the vehicle. 
     A requested deceleration value is calculated (step  204 ). The requested deceleration value preferably corresponds to a measure of deceleration of the vehicle corresponding to the braking request received or obtained during step  202  above. Specifically, in one preferred embodiment, the requested deceleration value pertains to a deceleration of the vehicle that would result if braking torque were applied consistent with the braking request provided by the driver during step  202 . The requested deceleration value is preferably calculated by the processor  114  of  FIG. 1 . 
     A determination is made as to whether the requested deceleration value calculated in step  204  is greater than a first predetermined deceleration threshold (step  206 ). In a preferred embodiment, the first predetermined deceleration threshold comprises a value above which it would be desirable to provide different amounts of braking pressure to the first and second axles using dual channel blending. In one preferred embodiment, the first predetermined deceleration threshold comprises an acceptable value of deceleration for a single axle. The first predetermined deceleration threshold may vary depending on the type of vehicle. In one exemplary embodiment, the first predetermined deceleration threshold is in the range of 0.15 g through 0.25 g for certain vehicles. However, this may vary in other embodiments. Also in a preferred embodiment, the first predetermined deceleration threshold is stored in the memory  118  of  FIG. 1  as one of the threshold values  122  of  FIG. 1 . In addition, in a preferred embodiment, the determination of step  206  is made by the processor  114  of  FIG. 1 . 
     If it is determined in step  206  that the requested deceleration value is greater than the first predetermined deceleration threshold, then a determination is made as to whether single channel blending is being used in a current iteration of the process  200  (step  208 ). In a preferred embodiment, this determination is made by the processor  114  of  FIG. 1 . 
     If it is determined in step  208  that single channel blending is not being used in a current iteration of the process  200 , then braking is applied to the first and second axles using dual channel blending (step  210 ). Specifically, in a preferred embodiment, during step  210  the braking is applied with a first pressure amount of hydraulic or other braking pressure applied to the first axle  130  of  FIG. 1  (the regenerative axle) and with a second pressure amount of hydraulic or other braking pressure applied to the second axle  132  of  FIG. 1  (the non-regenerative axle), with the second pressure amount being greater than or equal to the first pressure amount. In a preferred embodiment, braking is applied in step  210  using the dual channel blending until a driver requested brake torque in a subsequent iteration has fallen below a second predetermined deceleration threshold that indicates that the driver has released the brake pedal, as described in greater detail further below in connections with steps  216  and  218 . 
     In addition, during step  210 , regenerative braking is preferably provided using the first axle  130  of  FIG. 1 . In preferred embodiment, the first pressure amount and the second pressure amount are allocated or provided in a manner such that the vehicle is neutrally biased with respect to braking. Thus, the second pressure amount is preferably greater than or equal to the first pressure amount during step  210 . In a most preferred embodiment, the second pressure amount applied to the non-regenerative second braking axle  132  of  FIG. 1  is greater than the first pressure applied to the regenerative first braking axle  130  of  FIG. 1  during step  210 . Following step  210 , the process preferably returns to the above-referenced step  202 , as additional braking requests are received, and the process thereafter preferably continues through various iterations during the braking event. 
     Conversely, if it is determined in step  208  that single channel blending is being used in a current iteration of the process  200 , then braking is applied to the first and second axles using a transition to dual channel blending (step  211 ). Specifically, in a preferred embodiment, during step  211  the braking is applied with respective first and second pressure amounts to the first and second axles  130 ,  132  of  FIG. 1  such that the difference between the second pressure amount and the first pressure amount gradually increases over this period of time until they reach the levels associated with step  210 . In one preferred embodiment, this period of time is equal to approximately 0.5 seconds. However, this may vary in other embodiments. In one preferred embodiment, a linear transition is used. However, this may vary in other embodiments. Once the transition of step  211  is complete, the process proceeds to the above-referenced step  210 , as unequal braking pressure is applied to the different axles using dual channel blending. 
     Returning now to step  206 , if it is determined in step  206  that the requested deceleration value is less than or equal to the first predetermined deceleration threshold, then a determination is made as to whether dual channel blending is being used in a current iteration of the process  200  (step  212 ). In a preferred embodiment, this determination is made by the processor  114  of  FIG. 1 . 
     If it is determined in step  212  that dual channel blending is not being used in a current iteration of the process  200 , then braking is applied to the first and second axles using single channel blending (step  214 ). Specifically, in a preferred embodiment, during step  214  the braking is applied with a first pressure amount of hydraulic or other braking pressure applied to the first axle  130  of  FIG. 1  (the regenerative axle) and with a second pressure amount of hydraulic or other braking pressure applied to the second axle  132  of  FIG. 1  (the non-regenerative axle), with the second pressure amount being equal to the first pressure amount. 
     In addition, during step  214 , regenerative braking is also preferably provided using the first axle  130  of  FIG. 1 . In a most preferred embodiment, the first pressure amount and the second pressure amount are equal during step  214  irrespective of the amount of regenerative braking on the first axle. Following step  214 , the process preferably returns to the above-referenced step  202 , as additional braking requests are received, and the process thereafter preferably continues through various iterations during the braking event. 
     Conversely, if it is determined in step  212  that dual channel blending is being used in a current iteration of the process  200 , then a determination is made as to whether the requested deceleration value is less than a second predetermined deceleration threshold (step  216 ). In a preferred embodiment, the second predetermined deceleration threshold comprises a value such that, when the requested deceleration value is less than the second predetermined deceleration threshold, this indicates that the driver has released the brake pedal. Also in a preferred embodiment, the second predetermined deceleration threshold is stored in the memory  118  of  FIG. 1  as one of the threshold values  122  of  FIG. 1 . In addition, in a preferred embodiment, the determination of step  216  is made by the processor  114  of  FIG. 1 . 
     If it is determined in step  216  that the requested deceleration value is greater than or equal to the second predetermined deceleration threshold, then the process returns to the above-referenced step  210 , and unequal braking pressure is applied using dual channel blending. The process then returns to step  202 , as described above, as additional braking requests are received. In a preferred embodiment, the braking continues in this manner using dual channel blending until there is a determination in a subsequent iteration of step  216  that the requested deceleration value is less than the second predetermined deceleration threshold. 
     Once it is determined in an iteration of step  216  that the requested deceleration value is less than the second predetermined deceleration threshold, braking is then applied to the first and second axles using a transition to single channel blending (step  218 ). Specifically, in a preferred embodiment, during step  218  the braking is applied with respective first and second pressure amounts to the first and second axles  130 ,  132  of  FIG. 1  such that the difference between the second pressure amount and the first pressure amount gradually decreases over this period of time until they reach the levels associated with step  214 . In one preferred embodiment, this period of time is equal to approximately 0.5 seconds. However, this may vary in other embodiments. In one preferred embodiment, a linear transition is used. However, this may vary in other embodiments. Once the transition of step  218  is complete, the process proceeds to the above-referenced step  214 , as braking pressure is applied to the different axles using single channel blending. 
     The process  200  thereby provides apportionment of braking pressure to different axles of the vehicle. Specifically, in accordance with a preferred embodiment, an equal apportionment of braking pressure is generally provided to the first and second axles  130 ,  132  of  FIG. 1  using single channel blending when the requested deceleration value is less than or equal to the first predetermined deceleration threshold (step  214 ). Additionally, an unequal apportionment of braking pressure is generally provided to the first and second axles  130 ,  132  of  FIG. 1  using dual channel blending when the requested deceleration value is less than or equal to the first predetermined deceleration threshold (step  210 ). A smooth transition is provided from the single channel blending of step  214  to the dual channel blending of step  210  when the requested deceleration value is greater than the predetermined deceleration threshold and single channel blending is being used in a most recent iteration (step  211 ). In addition, a smooth transition is provided from the dual channel blending of step  210  to the single channel blending of step  214  when the requested deceleration value is less than or equal to the first predetermined deceleration threshold, dual channel blending is being used in a most recent iteration, and the requested deceleration value is less than the second predetermined deceleration threshold (step  218 ). As a result, the process  200  of  FIG. 2  provides reduced inconsistencies and non-linearities that might otherwise develop from pressure changes for the braking system, and provides an improved experience for the driver of the vehicle. 
     Turning now to  FIG. 3 , a graphical representation  300  is provided of various parameters pertaining to the brake controller  104  of  FIG. 1  and the process  200  of  FIG. 2  for an exemplary scenario in which the vehicle is being operated, in accordance with an exemplary embodiment of the present invention. Specifically, the graphical representation  300  of  FIG. 1  depicts a requested braking torque  302  parameter, a front braking pressure  304  parameter, a rear braking pressure  306  parameter, a boost pressure  308  parameter, and vehicle speed  310  parameter. 
     The requested braking torque  302  corresponds to the braking requests of step  202  of the process  200  of  FIG. 2 . The front braking pressure  304  preferably corresponds to the amount of braking pressure applied to the second braking axle  132  of  FIG. 1  (preferably a front, non-regenerative braking axle), and as referenced in  FIG. 2  as the second pressure amount and applied during steps  210 ,  211 ,  214 , and  218  of the process  200  of  FIG. 2 . The rear braking pressure  306  preferably corresponds to the amount of braking pressure applied to the first braking axle  130  of  FIG. 1  (preferably a rear, regenerative braking axle), and as referenced in  FIG. 2  as the first pressure amount and applied during steps  210 ,  211 ,  214 , and  218  of the process  200  of  FIG. 2 . The boost pressure  308  preferably corresponds to an overall boost pressure of the braking system  100  of  FIG. 1  and, specifically, of the axles  130 ,  132  as combined in the braking system  100  of  FIG. 1 . The vehicle speed  310  comprises a speed of the vehicle as a result of implementing the requested deceleration value of the vehicle of step  204  and the braking pressure as applied during steps  210 ,  211 ,  214 , and  218  of the process  200  of  FIG. 2 . 
     As shown in  FIG. 3 , once the vehicle speed  310  falls below a certain threshold (namely, 5.5 m/s in the depicted embodiment and under the exemplary conditions of  FIG. 3 ) at point  312  of  FIG. 3  (preferably corresponding to the requested deceleration value increasing beyond the first predetermined deceleration threshold in step  206  of the process  200  of  FIG. 2 ), the braking pressure requests to both the first and second axles  130 ,  132  of  FIG. 1  are ramped up thereafter. Specifically, the front braking pressure  304  and the rear braking pressure  306  both increase together after a corresponding point  314  of  FIG. 3  (preferably corresponding to steps  210  and  211  of the process  200  of  FIG. 2 , after the requested deceleration value has increased above the first predetermined deceleration threshold). Subsequently, the front braking pressure  304  and the rear braking pressure  306  both decrease after a corresponding point  316  of  FIG. 3  (preferably corresponding to steps  214  and  218  of the process  200  of  FIG. 2 , after the requested deceleration value has subsequently decreased below the second predetermined deceleration threshold). 
     Also as shown in  FIG. 3 , the front braking pressure  304  and the rear braking pressure  306  are preferably nearly equal to one another during most of the exemplary braking event depicted in  FIG. 3 . Also as depicted in  FIG. 3 , the front braking pressure  304  and the rear braking pressure  306  are also preferably equal to the boost pressure  308  during most of the braking event of  FIG. 3 . Accordingly, a smooth driving experience with consistent and substantially linear deceleration is provided for the driver of the vehicle in accordance with an exemplary embodiment. 
     Accordingly, improved methods and systems are provided for controlling braking of a vehicle with multiple axles. The improved methods and systems adjust the apportionment of braking pressure between the different axles depending on the values of a deceleration value of the vehicle. Specifically, single channel blending is used generally when a requested deceleration value for the vehicle is less than or equal to a first predetermined deceleration threshold. Dual channel blending is used generally when the requested deceleration value for the vehicle is greater than the first predetermined deceleration. A transition from single channel blending to dual channel blending is provided when the requested deceleration value for the vehicle is greater than the first predetermined deceleration threshold and provided further that single channel blending is being used in the most recent iteration. In addition, a transition from dual channel blending to single channel blending is provided when the requested deceleration value for the vehicle is less than or equal to the first predetermined deceleration threshold, dual channel blending is being used in the most recent iteration, and the requested deceleration value for the vehicle has fallen below the second predetermined deceleration threshold (i.e. when the driver has released the brake pedal). As a result, a more consistent and linear deceleration and an improved driving experience is provided in accordance with exemplary preferred embodiments of the present invention. 
     It will be appreciated that the disclosed methods and systems may vary from those depicted in the Figures and described herein. For example, as mentioned above, the brake controller  104  of  FIG. 1  may be disposed in whole or in part in any one or more of a number of different vehicle units, devices, and/or systems. In addition, it will be appreciated that certain steps of the process  200  may vary from those depicted in  FIG. 2  and/or described herein in connection therewith. It will similarly be appreciated that certain steps of the process  200  may occur simultaneously or in a different order than that depicted in  FIG. 2  and/or described herein in connection therewith. It will similarly be appreciated that the disclosed methods and systems may be implemented and/or utilized in connection with any number of different types of automobiles, sedans, sport utility vehicles, trucks, and/or any of a number of other different types of vehicles, and in controlling any one or more of a number of different types of vehicle infotainment systems. 
     While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims and the legal equivalents thereof.