Patent ID: 12214668

The figures are not exhaustive and do not limit the present disclosure to the precise form disclosed.

DETAILED DESCRIPTION

As alluded to above, hybrid vehicles can reduce emissions and improve fuel economy by operating in an electric-only travel mode where the ICE is shut off, and the electric motor(s) in the hybrid vehicle serve as the sole source of motive power. Similarly, in many hybrid vehicles the ICE may be shut off during braking, coasting, and when the vehicle comes to a stop. In these situations, the ICE must be decoupled from the drivetrain of the vehicle before it is shut off. In conventional hybrid vehicles, an electronic control unit (ECU) in the vehicle manages this selective decoupling/shut off process. For example, in response to a driver of a hybrid vehicle applying the brakes (or lifting their foot off the accelerator pedal), the ECU may decouple the ICE from the drivetrain of the vehicle, and shut off the ICE.

Currently, no hybrid vehicle on the market which selectively shuts off the ICE during operation, has a manual transmission. This is partly due to the manual process involved in decoupling the ICE from the drivetrain in conventional manual transmission vehicles. As alluded to above, in manual transmission vehicles, a driver decouples the ICE from the drivetrain of the vehicle by disengaging a clutch. Traditionally, the driver disengages the clutch pressing down a clutch pedal which is mechanically and/or hydraulically connected to the clutch. This is typically done during gear changes (to prevent engine stalling), and on occasion when the vehicle is stopped but the ICE is still on. However, as alluded to above, during the normal operation of hybrid vehicles, there are myriad situations where the ICE must be decoupled from the drivetrain of the vehicle in order to shut the ICE off (e.g. during electric-only travel mode, during braking, while coasting, etc.). Accordingly, it is unrealistic to expect the average driver to be able to adequately manage the selective decoupling of the ICE that is required during operation of a hybrid vehicle.

There are a few clutch actuation systems which make integration of a manual transmission in a hybrid vehicle more realistic. In particular, systems like clutch-by-wire enable automated/assisted control of the clutch by an ECU in a vehicle. In contrast to traditional clutch systems, in clutch-by-wire systems, there is no mechanical/hydraulic connection between the clutch pedal and the clutch itself. Instead, an electronic sensor communicates the position of the clutch pedal (by wire) to an electronic control unit (ECU), and the ECU controls an actuator which engages/disengages the clutch. Importantly, because the ECU directly controls actuation of the clutch, automated/assisted clutch control is enabled. In this way, a clutch-by-wire system may be used to when integrating a manual transmission in a hybrid vehicle.

However, clutch-by-wire systems have some drawbacks. As alluded to above, without the traditional mechanical/hydraulic connection between the clutch pedal and operation of the clutch, clutch-by-wire systems lack the unique feel that many drivers associate with (and have come to love about) operating traditional manual transmission vehicles. Many driving enthusiasts enjoy operating manual transmission vehicles precisely because of the intimate mechanical connection they feel with the vehicle while driving. That connection is lessened with a clutch-by-wire system. Additionally, like with other drive-by-wire systems, clutch-by-wire systems can be less responsive to nuanced/precise driver operations than traditional mechanical systems. For at least the reasons stated above, a hybrid vehicle offering which feels and drives like a traditional manual is a niche which has yet to be occupied.

Accordingly, embodiments of the technology disclosed herein are directed to systems and methods which enable automated/assisted clutch control (and thereby enable integration of manual transmissions in hybrid vehicles), but preserve the familiar mechanical feeling that drivers of manual transmission vehicles are so fond of. As will be discussed in greater detail below, each of these embodiments involve blended control of the clutch (between driver and ECU) where the driver of the vehicle controls the clutch by compressing hydraulic fluid (e.g. the driver may press a foot pedal clutch connected to a piston in a hydraulic cylinder). In this way, the familiar mechanical feeling which drivers associate with operating a manual transmission vehicle is preserved. At the same time however, an ECU in the vehicle (which may be part of an autonomous driving system, or an emergency override system), may operate the clutch when a driver opts not to and/or fails to.

In specific embodiments of the disclosed technology, a shuttle valve may be used to blend control of clutch engagement between a driver of a vehicle and an ECU in the vehicle. In some embodiments, the clutch pedal may be mechanically connected to a piston in a first hydraulic cylinder (just like in a traditional mechanical/hydraulic clutch actuation system), and an ECU may actuate a second hydraulic cylinder. In these embodiments, the driver-actuated hydraulic cylinder and the ECU-actuated hydraulic cylinder may push fluid into opposite inlets of a shuttle valve assembly. Accordingly, the shuttle valve assembly will allow the fluid entering from the inlet with the greater pressure to flow through its outlet to a third hydraulic cylinder. The fluid pressure in this third hydraulic cylinder may be translated through a mechanical linkage to the clutch. In this way, both the driver and the ECU are able to effectuate clutch engagement.

A first feature of the aforementioned system architecture is that the shuttle valve, by its mechanical design, will always allow the actuator (driver or ECU) providing the greater pressure to control engagement of the clutch. This means that the driver and ECU may override each other to decouple the ICE from the manual transmission. This has important implications for operation of a hybrid vehicle, as well as safety.

In regards to operation of a hybrid vehicle, the ECU may decouple the ICE from the drivetrain (and shut it off), anytime it detects the driver beginning to brake or let off the throttle. In addition, the ECU may ensure that the ICE is decoupled and shut off during any electric-only travel mode. More generally, the ECU may decouple the ICE from the drivetrain and shut it off anytime it normally would during operation of a conventional (non-manual transmission) hybrid vehicle. In some embodiments, this system architecture enables a hybrid vehicle to operate in one mode where the driver controls operation of the clutch (e.g. “sport mode”), and another mode where the ECU controls operation of the clutch (e.g. “autonomous clutch control” or “hybrid mode”). For example, in the “sport mode”, the ICE may be left on during braking and/or coasting unless the driver elects to disengage the clutch. By contrast, in the “hybrid mode”, the ECU may disengage the clutch and shut off the ICE during braking and coasting. In this way, energy may be restored during regenerative braking, and fuel will be saved/emissions reduced.

In regards to safety, this system architecture provides a mechanical safety interlock for both the ECU and the driver. Specifically, for the ECU, this system facilitates autonomous emergency braking (i.e. if the driver is pushing on the accelerator, the ECU may step in and decouple the ICE from the transmission). For the driver, this system allows for emergency human/mechanical intervention if an autonomous/assisted driving system is driving the vehicle too fast or will not stop. This is an improvement over conventional clutch-by-wire systems which do not allow for mechanical human intervention which bypasses the ECU.

A second feature of this system architecture is the preservation of the familiar/natural feeling of a traditional mechanical-hydraulic-mechanical clutch actuation system. Specifically, the clutch pedal (and by extension the driver), has the same mechanical-hydraulic-mechanical connection to the clutch as it would in a traditional system. This produces the same feel and responsiveness that manual transmission enthusiasts have become accustomed to. Moreover, applied in a hybrid vehicle, this system architecture enables a vehicle offering which satisfies a niche market: a vehicle which is fun to drive (like a traditional manual), with the additional fuel economy and acceleration of a hybrid.

The systems and methods disclosed herein may be implemented with any of a number of different vehicles and vehicle types. For example, the systems and methods disclosed herein may be used with automobiles, trucks, recreational vehicles and other vehicles like on-or off-road vehicles. Generally, the systems and methods disclosed herein may be implemented in any hybrid vehicle (including the hybrid vehicle described in conjunction withFIG.3) with a manual transmission and a driver operated clutch. This may include vehicles with traditional foot pedal clutches, but it may also include vehicles where a driver operates a clutch by another means (e.g. a hand lever, a paddle shifter for clutch engagement, etc.).

FIG.1illustrates an example system architecture which may be used to blend control of clutch engagement between a driver and an ECU of hybrid vehicle10.

In the illustrated example a driver operated clutch pedal100is mechanically connected to a piston inside driver controlled hydraulic cylinder102. WhileFIG.1illustrates a clutch pedal, in other embodiments, other interfaces of vehicle10may be used to move the piston in driver controlled hydraulic cylinder102. For example, a hand lever, or an interface similar to a paddle shifter may be used to mechanically move the piston in driver controlled hydraulic cylinder102.

As alluded to above, when a driver of vehicle10pushes clutch pedal100, a piston inside driver controlled hydraulic cylinder102compresses fluid in the cylinder, building up fluid pressure. In this way, a driver of vehicle10is able to control the fluid pressure in driver controlled hydraulic cylinder102, just as a driver would in a traditional mechanical/hydraulic clutch system. This fluid pressure may be transmitted to shuttle valve116, via a hose or pipe connecting driver controlled hydraulic cylinder102and shuttle valve116.

In the illustrated example, ECU50is connected by wire to ECU controlled actuator112, which is mounted on ECU controlled hydraulic cylinder114. In some embodiments, ECU controlled actuator112may be an electromechanical actuator which can receive command signals (e.g. CAN commands) from ECU50, and in response to those command signals, mechanically move a piston inside ECU controlled hydraulic cylinder114. In other embodiments, ECU controlled actuator112may be an electro-hydraulic actuator which moves fluid in ECU controlled hydraulic cylinder114without moving a piston. Either way, ECU50is able to control the fluid pressure in ECU controlled hydraulic cylinder114. This fluid pressure may be transmitted to shuttle valve116, via a hose or pipe connecting ECU controlled hydraulic cylinder114and shuttle valve116.

As alluded to above, shuttle valve116is a valve which allows fluid to flow through it from only one of two sources. More specifically, shuttle valve116has two inlets, on opposite ends of its manifold, and one outlet between the two inlets. A tube inside shuttle valve116connects these three openings. Inside the tube, between the two inlets, is a blocking element (e.g. a ball or shuttle). This blocking element, which is able to move freely inside the tube, is the mechanism by which shuttle valve116is able to allow fluid from only one of two sources to flow through its outlet. More specifically, when fluid enters shuttle valve116from opposing inlets, the greater pressure fluid will push the blocking element against the opposite inlet, effectively preventing fluid from that inlet from flowing through the outlet. In this way, shuttle valve116effectively acts as an “or” gate.

In the illustrated example, a first inlet of shuttle valve116allows fluid from driver controlled hydraulic cylinder102(connected to shuttle valve116by hose or pipe) to flow into shuttle valve116. The second inlet of shuttle valve116allows fluid from ECU controlled hydraulic cylinder114(connected to shuttle valve116by hose or pipe) to flow into shuttle valve116. The outlet of shuttle valve116connects to hydraulic cylinder118by hose or pipe. Accordingly, as described in the previous paragraph, shuttle valve116is able to act as an “or” gate between driver controlled hydraulic cylinder102and ECU controlled hydraulic cylinder114. Put another way, only fluid from the greater pressure line will flow through the outlet of shuttle valve116, and be transmitted to hydraulic cylinder118. In this way, the illustrated system innovates a traditional mechanical/hydraulic clutch actuation system by enabling seamless automated/assisted clutch control by an ECU.

As alluded to above, hydraulic cylinder118may be connected by hose or pipe to the outlet of shuttle valve116. Fluid flowing from the outlet of shuttle valve116may enter hydraulic cylinder118, building up fluid pressure. This pressure may move a piston in hydraulic cylinder118, which may be connected by mechanical linkage to clutch15. This mechanical linkage may adjust the engagement of clutch15. For example, the piston may be mechanically connected to a push rod, which acts on a clutch fork. The clutch fork may act (directly or indirectly) on the middle of a diaphragm spring in clutch15. When the middle of the diaphragm spring is pushed in, clutch15may be partially, or completed disengaged. In this way, fluid pressure build up in hydraulic cylinder118may be translated into a mechanical force which disengages clutch15.

As will be described inFIG.3below, clutch15may be used to engage and disengage ICE14from manual transmission18. When engaged (or partially engaged) driving force generated by ICE14can be transmitted to one or more wheels34via clutch15, manual transmission18, a differential gear device28(not pictured), and a pair of axles30(not pictured). When disengaged, ICE14may be shut off. For example, during regenerative braking or coasting, ICE14may be disengaged from manual transmission18, and shut off in order to save fuel and reduce emissions.

In some embodiments vehicle10may also include pressure sensors54and56. Pressure sensor54may obtain the fluid pressure transmitted from driver controlled hydraulic cylinder102to shuttle valve116. Pressure sensor54may communicate the sensed pressure to ECU50, by wire. Similarly, pressure sensor56may obtain the fluid pressure transmitted from shuttle valve116to hydraulic cylinder118. This pressure may be used to monitor engagement of the clutch. Pressure sensor56may communicate the sensed pressure to ECU50, by wire. In some embodiments, ECU50may use these sensed pressures to determine when/if to provide clutch control assistance to the driver of vehicle10. For example, ECU50may use these sensed pressures to determine that a driver of hybrid vehicle10has not disengaged ICE14when stopped at an intersection. Accordingly, ECU50may disengage ICE14and shut it off in order to save fuel and reduce emissions.

Finally, it should be understood that in the context ofFIG.1, a fluid is any substance that deforms (flows) under an applied pressure/force. For example, the fluid used in the illustrated system architecture may be liquid (e.g. water, mineral oil, etc.) or gaseous.

FIG.2illustrates an example method by which blended control of clutch engagement between a driver and an ECU may be achieved. This method facilitates a number of system architectures (including the shuttle valve system architecture described above). For purposes of illustration, a few of these system architectures will be described in the paragraphs below.

In a first system architecture (i.e. the tandem/series system architecture), a driver controlled hydraulic cylinder and an ECU controlled hydraulic cylinder may be connected in series. More specifically, the outlet of an upstream hydraulic cylinder (either the driver controlled or ECU controlled hydraulic cylinder) may be connected to the inlet of a downstream hydraulic cylinder, and the outlet of the downstream hydraulic cylinder (the other of the driver controlled or ECU controlled hydraulic cylinder) may be connected to a hydraulic-mechanical linkage which adjusts engagement of a clutch based on fluid pressure. In some embodiments, the passage of fluid from the upstream hydraulic cylinder to the downstream hydraulic cylinder may be managed using a valve or seal which allows one way flow, such as a cone seal. For example, if the piston in the upstream hydraulic cylinder (e.g. the driver controlled hydraulic cylinder) is pushed, fluid from the upstream hydraulic cylinder may pass over a cone seal in the downstream hydraulic cylinder, and exit the outlet of the downstream hydraulic cylinder, thereby transferring the pressure of the fluid compressed in the upstream cylinder to the hydraulic-mechanical linkage which adjusts engagement of the clutch. If the piston in the downstream hydraulic cylinder (e.g. the ECU controlled hydraulic cylinder) is pushed, the fluid compressed in the downstream hydraulic cylinder may be transmitted directly to the hydraulic-mechanical linkage which adjusts engagement of the clutch. In this scenario, some fluid may enter the upstream cylinder to fill the void created by the fluid in the downstream hydraulic cylinder being compressed. In this way, pressure from either a first fluid compressed in the driver controlled hydraulic cylinder, or a second fluid compressed in the ECU controlled hydraulic cylinder, may be transmitted to the hydraulic-mechanical linkage which adjusts engagement of the clutch.

In a second system architecture, a driver controlled hydraulic cylinder and an ECU controlled hydraulic cylinder may each be part of parallel hydraulic systems which independently adjust engagement of the same clutch. For example, the driver controlled hydraulic cylinder may be connected to a first sub hydraulic-mechanical linkage configured to adjust clutch engagement based on the pressure of the fluid compressed in the driver controlled hydraulic cylinder (i.e. the first fluid). The ECU controlled hydraulic cylinder may be connected to a second sub hydraulic-mechanical linkage configured to adjust clutch engagement based on the pressure of the fluid compressed in the ECU controlled hydraulic cylinder (i.e. the second fluid). In some embodiments, the first and second hydraulic-mechanical linkages may comprise two concentric circles, each configured to push on the diaphragm spring of one clutch. Accordingly, by this mechanical design, the hydraulic-mechanical linkage which receives the greater pressure fluid (first or second) will control engagement of the clutch. In this way, as with the system architecture involving the shuttle valve, both driver and ECU may override the other to disengage the clutch by providing greater pressure.

A third system architecture which this method facilitates is the shuttle valve system architecture ofFIG.1. It should be understood that the illustrated method, as described in the paragraphs below, may facilitate system architectures in addition to those previously described.

At operation600, a hydraulic-mechanical linkage may receive at least one of a first fluid compressed by clutch-related input signals from a driver of a vehicle, and a second fluid compressed by clutch-related input signals from an ECU in the vehicle.

The clutch-related input signals from a driver may include the driver pushing on a foot pedal (i.e. a clutch pedal) connected to a piston in a driver controlled hydraulic cylinder, which compresses the first fluid. In other embodiments, clutch-related input signals from the driver may comprise the driver manipulating other interfaces of the vehicle in order to compress the first fluid. For example, a driver may push/pull a hand-lever which mechanically actuates a fluid pump.

The clutch-related input signals from the ECU may include the ECU sending control signals to an electronic actuator which, in response to the control signals, compresses the second fluid in an ECU controlled hydraulic cylinder. In some embodiments, the ECU controlled actuator may be a an electromechanical actuator which, in response to received control signals, mechanically moves a piston in the ECU controlled hydraulic cylinder. In other embodiments, the ECU controlled actuator may be an electro-hydraulic actuator which compresses the second fluid in the ECU controlled hydraulic cylinder without moving a piston.

In some embodiments, the clutch-related input signals from the ECU may be generated in response to brake-related and/or throttle-related input signals. For example, in a hybrid vehicle, a clutch-related input signal from the ECU may be generated when a driver of the vehicle pushes on a brake pedal, or lifts their foot off the accelerator pedal. Accordingly, as will be described in more detail below, the clutch-related input signals from the ECU may result in the clutch being disengaged, and the ICE decoupled from the manual transmission. In this way, the ICE may be decoupled from the manual transmission, and shut off during regenerative braking and or coasting.

The hydraulic-mechanical linkage which does the receiving may include a piston inside a hydraulic cylinder, connected by mechanical linkage to the clutch. For example, in some embodiments, a piston in a hydraulic cylinder may be connected to a pushrod-clutch fork linkage. This pushrod-clutch fork linkage may act on the diaphragm spring of a clutch, which disengages the clutch when pushed. As alluded to above, in some embodiments, the hydraulic-mechanical linkage may comprise two sub hydraulic-mechanical linkages. For example, the hydraulic-mechanical linkage may comprise two pistons inside two separate hydraulic cylinders, each mechanically connected to an independent pushrod-clutch fork linkage. As described above, these two independent pushrod-clutch fork linkages may be concentric circles configured to push on the diaphragm spring of the same clutch based on fluid pressure.

The hydraulic-mechanical linkage which does the receiving may receive one of the first and second fluids, or both. For example, in the shuttle valve system architecture, the hydraulic mechanical linkage will only receive the fluid having the greater pressure. Accordingly, the hydraulic-mechanical linkage will adjust engagement of the clutch based on the pressure of the greater pressure fluid. Similarly, in the tandem/series system architecture, the hydraulic-mechanical linkage will receive the fluid having the greatest pressure among (1) the first fluid (compressed by the driver), (2) the second fluid (compressed by the ECU), or in the rare case when both driver and ECU compress fluid at the same time, (3) a combination of the first fluid and the second fluid. Notably, even in the rare case where a combination of the first and second fluid is received by the hydraulic-mechanical linkage, the fluid having the higher pressure between the first and second fluid has been transmitted. Put another way, just like in the shuttle valve system architecture, driver and ECU may always override each other to disengage the clutch by providing greater pressure. Finally, in the system architecture involving two parallel/independent hydraulic systems, the hydraulic-mechanical linkage (i.e. the two sub hydraulic-mechanical linkages comprising concentric circles configured to push on the same clutch) may receive either one of, or both of, the first fluid and the second fluid. In the scenario where both the first and second fluid are received, by the mechanical design of this system, only the sub hydraulic-mechanical linkage which receives the fluid having the greater pressure will adjust the clutch.

At operation602, the hydraulic-mechanical linkage may adjust engagement of a clutch in accordance with one of the first or second fluids having a greater pressure. As described earlier, in system architectures such as the shuttle valve architecture, where only the fluid having the greater pressure (first or second) can be received, the hydraulic-mechanical linkage will adjust engagement of the clutch according to the pressure of the received fluid. Similarly, in system architectures such as the series/tandem hydraulic system architecture, where the hydraulic-mechanical linkage will receive the fluid having the greatest pressure among (1) the first fluid; (2) the second fluid; or (3) a combination of the first fluid and the second fluid; the hydraulic-mechanical linkage will adjust engagement of the clutch according to the pressure of the received fluid. In system architectures such as the parallel/independent hydraulic system architecture, where a first fluid may be received by a first sub hydraulic-mechanical linkage and a second fluid may be received by a second sub hydraulic-mechanical linkage, the sub hydraulic-mechanical linkage which receives the fluid having the greater pressure may adjust engagement of the clutch in accordance with the pressure of the greater pressure fluid. In these ways, the hydraulic-mechanical linkage may adjust engagement of the clutch in accordance with one of the first or second fluids having a greater pressure.

FIG.3illustrates a drive system of a hybrid vehicle10that may include an internal combustion engine (ICE)14and one or more electric motors22(which may also serve as generators) as sources of motive power. Driving force generated by the ICE14and motors22can be transmitted to one or more wheels34via a clutch15, a manual transmission18, a differential gear device28, and a pair of axles30.

As a hybrid vehicle, vehicle10may be driven/powered with either or both of ICE14and the motor(s)22as the drive source for travel. For example, a first travel mode may be an engine-only travel mode that only uses ICE14as the source of motive power. A second travel mode may be an electric-only travel mode that only uses the motor(s)22as the source of motive power. A third travel mode may be an hybrid-electric travel mode that uses ICE14and the motor(s)22as the sources of motive power. In the engine-only and hybrid-electric travel modes, vehicle10relies on the motive force generated at least by ICE14, and clutch15may be used to engage ICE14. In the electric-only travel mode, where vehicle10is powered by the motive force generated by motor22, clutch15may be disengaged and ICE14shut off.

ICE14can be an internal combustion engine such as a gasoline, diesel or similarly powered engine in which fuel is injected into and combusted in a combustion chamber. A cooling system12can be provided to cool the ICE14such as, for example, by removing excess heat from ICE14. For example, cooling system12can be implemented to include a radiator, a water pump and a series of cooling channels. In operation, the water pump circulates coolant through the ICE14to absorb excess heat from the ICE. The heated coolant is circulated through the radiator to remove heat from the coolant, and the cold coolant can then be recirculated through the ICE. A fan may also be included to increase the cooling capacity of the radiator. The water pump, and in some instances the fan, may operate via a direct or indirect coupling to the driveshaft of ICE14. In other applications, either or both the water pump and the fan may be operated by electric current such as from battery44.

An output control circuit14A may be provided to control drive (output torque) of ICE14. Output control circuit14A may include a throttle actuator to control an electronic throttle valve that controls fuel injection, an ignition device that controls ignition timing, and the like. Output control circuit14A may execute output control of ICE14according to a command control signal(s) supplied from an electronic control unit50, described below. Such output control can include, for example, throttle control, fuel injection control, and ignition timing control.

Motor22can also be used to provide motive power in vehicle10and may be powered electrically via a battery44. More specifically, motor22can be powered by battery44to generate motive force to move the vehicle and adjust vehicle speed. Motor22can also function as a generator to generate electrical power such as, when coasting or braking. Motor22may be connected to battery44via an inverter42. Battery44may also be used to power other electrical or electronic systems in the vehicle. Battery44can include, for example, one or more batteries, capacitive storage units, or other storage reservoirs suitable for storing electrical energy that can be used to power motor22. When battery44is implemented using one or more batteries, the batteries can include, for example, nickel metal hydride batteries, lithium ion batteries, lead acid batteries, nickel cadmium batteries, lithium ion polymer batteries, and other types of batteries. Battery44may be charged by a battery charger45that receives energy from internal combustion engine14. For example, an alternator or generator may be coupled directly or indirectly to a drive shaft of internal combustion engine14to generate an electrical current as a result of the operation of internal combustion engine14. A clutch can be included to engage/disengage the battery charger45. Battery44may also be charged by motor22such as, for example, by regenerative braking or by coasting during which time motor22operate as generator.

An electronic control unit50(described below) may be included and may control the electric drive components of the vehicle as well as other vehicle components. For example, electronic control unit50may control an electronic actuator which adjusts engagement of clutch15. As other examples, electronic control unit50may control inverter42, adjust driving current supplied to motor22, and adjust the current received from motor22during regenerative coasting and breaking. As a more particular example, output torque of the motor22can be increased or decreased by electronic control unit50through the inverter42.

As described above, clutch15can be included to engage and disengage ICE14from the drivetrain of the vehicle. In the illustrated example, a crankshaft32, which is an output member of ICE14, may be selectively coupled to the motor22via clutch15. However, in other embodiments (e.g. mild hybrids), motors22may be coupled directly to wheels34, and may provide primary or supplemental power to the wheels during acceleration. Clutch15can be implemented as, for example, a multiple disc type hydraulic frictional engagement device, where engagement can be controlled in the manner described above. Clutch15may be controlled such that its engagement state is complete engagement, partial/slip engagement, and complete disengagement, depending on the pressure applied to the clutch. For example, a torque capacity of clutch15may be controlled according to the hydraulic pressure supplied from one of the hydraulic control circuits described in conjunction withFIGS.1and2. As described above, when clutch15is engaged, power transmission is provided in the power transmission path between the crankshaft32and manual transmission18. On the other hand, when clutch15is disengaged, motive power from ICE14is not delivered to manual transmission18, and ICE14may be shut off. In a partial/slip engagement state, clutch15is engaged, and motive power is provided to manual transmission18according to a torque capacity (transmission torque) of the clutch15.

As alluded to above, vehicle10may include an electronic control unit50. Electronic control unit50may include circuitry to control various aspects of the vehicle operation. Electronic control unit50may include, for example, a microcomputer that includes a one or more processing units (e.g., microprocessors), memory storage (e.g., RAM, ROM, etc.), and I/O devices. The processing units of electronic control unit50, execute instructions stored in memory to control one or more electrical systems or subsystems in the vehicle. Electronic control unit50can include a plurality of electronic control units such as, for example, an electronic engine control module, a powertrain control module, a clutch control module, a transmission control module, a suspension control module, a body control module, and so on. As a further example, electronic control units can be included to control systems and functions such as doors and door locking, lighting, human-machine interfaces, cruise control, telematics, braking systems (e.g., ABS or ESC), battery management systems, and so on. These various control units can be implemented using two or more separate electronic control units, or using a single electronic control unit.

In the example illustrated inFIG.3, electronic control unit50receives information from a plurality of sensors included in vehicle10. For example, electronic control unit50may receive signals that indicate vehicle operating conditions or characteristics, or signals that can be used to derive vehicle operating conditions or characteristics. These may include, but are not limited to accelerator operation amount, ACC, a revolution speed, NE, of internal combustion engine14(engine RPM), a rotational speed, NMG, of the motor22(motor rotational speed), and vehicle speed, NV. As discussed inFIG.1, these may also include the pressure of the hydraulic fluid flowing out of driver controlled hydraulic cylinder102, PD, pressure of the hydraulic fluid flowing out the outlet of the shuttle valve116, PS, and brake operation amount/pressure, B. Accordingly, vehicle10can include a plurality of sensors52that can be used to detect various conditions internal or external to the vehicle and provide sensed conditions to engine control unit50(which, again, may be implemented as one or a plurality of individual control circuits). In one embodiment, sensors52may be included to detect one or more conditions directly or indirectly such as, for example, fuel efficiency, EF, motor efficiency, EMG, hybrid (internal combustion engine14+MG12) efficiency, acceleration, ACC, etc.

In some embodiments, one or more of the sensors52may include their own processing capability to compute the results for additional information that can be provided to electronic control unit50. In other embodiments, one or more sensors may be data-gathering-only sensors that provide only raw data to electronic control unit50. In further embodiments, hybrid sensors may be included that provide a combination of raw data and processed data to electronic control unit50. Sensors52may provide an analog output or a digital output.

Sensors52may be included to detect not only vehicle conditions but also to detect external conditions as well. Sensors that might be used to detect external conditions can include, for example, sonar, radar, lidar or other vehicle proximity sensors, and cameras or other image sensors. Image sensors can be used to detect, for example, traffic signs indicating a current speed limit, road curvature, obstacles, and so on. Still other sensors may include those that can detect road grade. While some sensors can be used to actively detect passive environmental objects, other sensors can be included and used to detect active objects such as those objects used to implement smart roadways that may actively transmit and/or receive data or other information.

FIG.4illustrates an example architecture for operating engagement of a clutch autonomously and/or entering an assist mode in accordance with one embodiment of the systems and methods described herein. Referring now toFIG.4, in this example, assist mode detection and activation system200includes an assist-mode detection/activation circuit210, a plurality of sensors152, and a plurality of vehicle systems158. Sensors152and vehicle systems158can communicate with assist-mode detection/activation circuit210via a wired or wireless communication interface. Although sensors152and vehicle systems158are depicted as communicating with assist-mode detection/activation circuit210, they can also communicate with each other as well as with other vehicle systems. Assist-mode detection/activation circuit210can be implemented as an ECU or as part of an ECU such as, for example electronic control unit50. In other embodiments, assist-mode detection/activation circuit210can be implemented independently of the ECU.

Assist-mode detection/activation circuit210in this example includes a communication circuit201, a decision circuit (including a processor206and memory208in this example) and a power supply212. Components of assist-mode detection/activation circuit210are illustrated as communicating with each other via a data bus, although other communication in interfaces can be included. Assist-mode detection/activation circuit210in this example also includes a manual assist switch205that can be operated by the user to manually select the assist mode.

Processor206can include a GPU, CPU, microprocessor, or any other suitable processing system. The memory208may include one or more various forms of memory or data storage (e.g., flash, RAM, etc.) that may be used to store the calibration parameters, images (analysis or historic), point parameters, instructions and variables for processor206as well as any other suitable information. Memory208, can be made up of one or more modules of one or more different types of memory, and may be configured to store data and other information as well as operational instructions that may be used by the processor206to assist-mode detection/activation circuit210.

Although the example ofFIG.4is illustrated using processor and memory circuitry, as described below with reference to circuits disclosed herein, decision circuit203can be implemented utilizing any form of circuitry including, for example, hardware, software, or a combination thereof. By way of further example, one or more processors, controllers, ASICs, PLAs, PALs, CPLDs, FPGAs, logical components, software routines or other mechanisms might be implemented to make up a assist-mode detection/activation circuit210.

Communication circuit201either or both a wireless transceiver circuit202with an associated antenna214and a wired I/O interface204with an associated hardwired data port (not illustrated). As this example illustrates, communications with assist-mode detection/activation circuit210can include either or both wired and wireless communications circuits201. Wireless transceiver circuit202can include a transmitter and a receiver (not shown) to allow wireless communications via any of a number of communication protocols such as, for example, WiFi, Bluetooth, near field communications (NFC), Zigbee, and any of a number of other wireless communication protocols whether standardized, proprietary, open, point-to-point, networked or otherwise. Antenna214is coupled to wireless transceiver circuit202and is used by wireless transceiver circuit202to transmit radio signals wirelessly to wireless equipment with which it is connected and to receive radio signals as well. These RF signals can include information of almost any sort that is sent or received by assist-mode detection/activation circuit210to/from other entities such as sensors152and vehicle systems158.

Wired I/O interface204can include a transmitter and a receiver (not shown) for hardwired communications with other devices. For example, wired I/O interface204can provide a hardwired interface to other components, including sensors152and vehicle systems158. Wired I/O interface204can communicate with other devices using Ethernet or any of a number of other wired communication protocols whether standardized, proprietary, open, point-to-point, networked or otherwise.

Power supply210can include one or more of a battery or batteries (such as, e.g., Li-ion, Li-Polymer, NiMH, NiCd, NiZn, and NiH2, to name a few, whether rechargeable or primary batteries), a power connector (e.g., to connect to vehicle supplied power, etc.), an energy harvester (e.g., solar cells, piezoelectric system, etc.), or it can include any other suitable power supply.

Sensors152can include, for example, sensors52such as those described above with reference to the examples ofFIG.3. Sensors152can include additional sensors that may or not otherwise be included on a standard vehicle10with which the turn assist-mode system200is implemented. In the illustrated example, sensors152include vehicle acceleration sensors212, vehicle speed sensors214, wheelspin sensors2116(e.g., one for each wheel), a tire pressure monitoring system (TPMS)220, accelerometers such as a 3-axis accelerometer222to detect roll, pitch and yaw of the vehicle, vehicle clearance sensors224, left-right and front-rear slip ratio sensors226, and environmental sensors228(e.g., to detect salinity or other environmental conditions). Additional sensors232can also be included as may be appropriate for a given implementation of assist-mode system200. For example, additional sensors which sense (1) the fluid pressure transmitted from driver controlled hydraulic cylinder102to shuttle valve116and (2) the fluid pressure transmitted from shuttle valve116to hydraulic cylinder118, may be included. Information from these sensors may be used to monitor driver clutch control operations and engagement of the clutch. Sensors152may also include sensors which detect brake operation amount and throttle operation amount. Electronic control unit50may use information from these sensors to determine whether to disengage clutch15(and shut it off ICE14) during regenerative braking and/or coasting.

Vehicle systems158can include any of a number of different vehicle components or subsystems used to control or monitor various aspects of the vehicle and its performance. In this example, the vehicle systems158include a GPS or other vehicle positioning system272; clutch control system274to control engagement of the clutch; engine control circuits276to control the operation of engine (e.g. ICE14); cooling systems278to provide cooling for the motors, power electronics, the engine, or other vehicle systems; suspension system280such as, for example, an adjustable-height fluid suspension system, and other vehicle systems.

During operation, assist mode detection/activation circuit210can receive information from various vehicle sensors to determine whether the assist mode should be activated. Also, the driver may manually activate the assist mode by operating assists switch205. Communication circuit201can be used to transmit and receive information between assist-mode detection/activation circuit210and sensors152, and assist-mode detection/activation circuit210and vehicle systems158. For example, communication circuit201may receive data from a brake operation sensor indicating that brakes are being applied in vehicle10. Accordingly, communication circuit201may send activation signals to clutch control system274with instructions to disengage clutch15, and to ICE control circuit276with instructions to shut off ICE14. More generally, communication circuit201can be used to send activation signals to one or more of: clutch control system274to control engagement of the clutch (e.g. to disengage the clutch during regenerative braking); motor controllers276to, for example, control motor torque, motor speed of the various motors in the system; ICE control circuit276to, for example, control power to ICE14(e.g., to shut down the engine, or to ensure the engine is running to charge the batteries or allow more power to flow to the motors); cooling system278(e.g., to increase cooling system flow for one or more motors and their associated electronics); suspension system280(e.g., to increase ground clearance such as by increasing the ride height using the fluid suspension). The decision regarding what action to take via these various vehicle systems158can be made based on the information detected by sensors152.

As used herein, the terms circuit and component might describe a given unit of functionality that can be performed in accordance with one or more embodiments of the present application. As used herein, a component might be implemented utilizing any form of hardware, software, or a combination thereof. For example, one or more processors, controllers, ASICs, PLAs, PALs, CPLDs, FPGAs, logical components, software routines or other mechanisms might be implemented to make up a component. Various components described herein may be implemented as discrete components or described functions and features can be shared in part or in total among one or more components. In other words, as would be apparent to one of ordinary skill in the art after reading this description, the various features and functionality described herein may be implemented in any given application. They can be implemented in one or more separate or shared components in various combinations and permutations. Although various features or functional elements may be individually described or claimed as separate components, it should be understood that these features/functionality can be shared among one or more common software and hardware elements. Such a description shall not require or imply that separate hardware or software components are used to implement such features or functionality.

Where components are implemented in whole or in part using software, these software elements can be implemented to operate with a computing or processing component capable of carrying out the functionality described with respect thereto. One such example computing component is shown inFIG.5. Various embodiments are described in terms of this example-computing component500. After reading this description, it will become apparent to a person skilled in the relevant art how to implement the application using other computing components or architectures.

Referring now toFIG.5, computing system500may represent, for example, computing or processing capabilities found within desktop, laptop and notebook computers; hand-held computing devices (PDA's, smart phones, cell phones, palmtops, etc.); mainframes, supercomputers, workstations or servers; or any other type of special-purpose or general-purpose computing devices as may be desirable or appropriate for a given application or environment, such as for example, one or more of the elements or circuits illustrated inFIGS.3and4and described herein. Computing system500might also represent computing capabilities embedded within or otherwise available to a given device. For example, a computing system might be found in other electronic devices such as, for example, digital cameras, navigation systems, cellular telephones, portable computing devices, modems, routers, WAPs, terminals and other electronic devices that might include some form of processing capability.

Computing system500might include, for example, one or more processors, controllers, control modules, or other processing devices, such as a processor504. Processor504might be implemented using a general-purpose or special-purpose processing engine such as, for example, a microprocessor (whether single-, dual- or multi-core processor), signal processor, graphics processor (e.g., GPU) controller, or other control logic. In the illustrated example, processor504is connected to a bus502, although any communication medium can be used to facilitate interaction with other components of computing system500or to communicate externally.

Computing system500might also include one or more memory modules, simply referred to herein as main memory508. For example, in some embodiments random access memory (RAM) or other dynamic memory, might be used for storing information and instructions to be executed by processor504. Main memory508might also be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor504. Computing system500might likewise include a read only memory (“ROM”) or other static storage device coupled to bus502for storing static information and instructions for processor504.

The computing system500might also include one or more various forms of information storage mechanism510, which might include, for example, a media drive512and a storage unit interface520. The media drive512might include a drive or other mechanism to support fixed or removable storage media514. For example, a hard disk drive, a floppy disk drive, a magnetic tape drive, an optical disk drive, a CD or DVD drive (R or RW), a flash drive, or other removable or fixed media drive might be provided. Accordingly, storage media514might include, for example, a hard disk, a floppy disk, magnetic tape, cartridge, optical disk, a CD or DVD, or other fixed or removable medium that is read by, written to or accessed by media drive512. As these examples illustrate, the storage media514can include a computer usable storage medium having stored therein computer software or data.

In alternative embodiments, information storage mechanism510might include other similar instrumentalities for allowing computer programs or other instructions or data to be loaded into computing system500. Such instrumentalities might include, for example, a fixed or removable storage unit522and an interface520. Examples of such storage units522and interfaces520can include a program cartridge and cartridge interface, a removable memory (for example, a flash memory or other removable memory module) and memory slot, a flash drive and associated slot (for example, a USB drive), a PCMCIA slot and card, and other fixed or removable storage units522and interfaces520that allow software and data to be transferred from the storage unit522to computing system500.

Computing system500might also include a communications interface524. Communications interface524might be used to allow software and data to be transferred between computing system500and external devices. Examples of communications interface524might include a modem or softmodem, a network interface (such as an Ethernet, network interface card, WiMedia, IEEE 802.XX, Bluetooth® or other interface), a communications port (such as for example, a USB port, IR port, RS232 port, or other port), or other communications interface. Software and data transferred via communications interface524might typically be carried on signals, which can be electronic, electromagnetic (which includes optical) or other signals capable of being exchanged by a given communications interface524. These signals might be provided to communications interface524via a channel528. This channel528might carry signals and might be implemented using a wired or wireless communication medium. Some examples of a channel might include a phone line, a cellular link, an RF link, an optical link, a network interface, a local or wide area network, and other wired or wireless communications channels.

In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as, for example, memory508, storage unit520, media514, and channel528. These and other various forms of computer program media or computer usable media may be involved in carrying one or more sequences of one or more instructions to a processing device for execution. Such instructions embodied on the medium, are generally referred to as “computer program code” or a “computer program product” (which may be grouped in the form of computer programs or other groupings). When executed, such instructions might enable the computing system500to perform features or functions of the disclosed technology as discussed herein.

It should be understood that the various features, aspects and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described. Instead, they can be applied, alone or in various combinations, to one or more other embodiments, whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus, the breadth and scope of the present application should not be limited by any of the above-described exemplary embodiments.

Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing, the term “including” should be read as meaning “including, without limitation” or the like. The term “example” is used to provide exemplary instances of the item in discussion, not an exhaustive or limiting list thereof. The terms “a” or “an” should be read as meaning “at least one,” “one or more” or the like; and adjectives such as “conventional,” “traditional,” “normal,” “standard,” “known.” Terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time. Instead, they should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. Where this document refers to technologies that would be apparent or known to one of ordinary skill in the art, such technologies encompass those apparent or known to the skilled artisan now or at any time in the future.

The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent. The use of the term “component” does not imply that the aspects or functionality described or claimed as part of the component are all configured in a common package. Indeed, any or all of the various aspects of a component, whether control logic or other components, can be combined in a single package or separately maintained and can further be distributed in multiple groupings or packages or across multiple locations.

Additionally, the various embodiments set forth herein are described in terms of exemplary block diagrams, flow charts and other illustrations. As will become apparent to one of ordinary skill in the art after reading this document, the illustrated embodiments and their various alternatives can be implemented without confinement to the illustrated examples. For example, block diagrams and their accompanying description should not be construed as mandating a particular architecture or configuration.