ENGINE SPEED CONTROL BY MEANS OF ALTERNATOR LOAD DELETION

Abstract

Procedure (300) comprising the following; Rules for the idling of an engine (22) coupled with an alternator (42) which provides electrical power to various electrical devices in a vehicle driven by the engine (22); a first mode of engine idle control which is active when a reduction or shutdown of electrical power applied to the selected electrical devices would be perceptible to an operator of the vehicle; During the first engine idle control mode, a permanent ignition timing value of the engine (22) is advanced in a retardation direction to an offset retarded value, and if the engine speed is lower than desired, the ignition timing is advanced before the offset retarded value, and if the engine speed is higher than desired, the ignition timing is retarded beyond the offset retarded value; a second mode of engine idle control, which is active when a reduction or shutdown of electrical power applied to the selected electrical devices would not be perceptible to a vehicle operator; and During the second idle control mode, the offset delayed value is removed and electrical power for the selected devices is deactivated or reduced when the engine speed is lower than desired, and the ignition timing is delayed beyond the permanent state ignition timing value when the engine speed is higher than desired.

Description

Technical field

[0001] The present application relates to methods and systems for controlling the idling of an internal combustion engine while simultaneously optimizing fuel economy and regenerative braking during deceleration. Background / Summary

[0002] Idle speed control systems for internal combustion engines change the throttle position to increase or decrease the engine speed to a desired level. Because the throttle valve is coupled to the air intake valves of several cylinders via an intake manifold, there is a time delay before the change in throttle position results in a change in engine torque and thus the idle speed. Advancing or retarding the ignition timing is therefore also used to provide a faster response time. However, advancing the ignition timing beyond a constant or setpoint can cause knocking. To prevent knocking during idle speed control, the constant value is retarded to an offset value, allowing the ignition timing to be advanced before the offset value, if necessary, to increase engine speed without causing knocking.

[0003] DE 10 2007 050 855 B4 discloses a method for controlling an internal combustion engine in a vehicle, wherein the internal combustion engine is subjected to a torque load from a generator coupled to the internal combustion engine. DE 10 2004 017 503 A1 relates to a motor system comprising a motor, an alternator, a load, and a controller, wherein the controller reduces an alternator load on the motor in response to the load increase. DE 102 05 024 C1 describes a device for controlling the torque of a vehicle's drive unit. DE 699 24 801 T2 deals with a device for controlling the speed of an internal combustion engine to a predetermined target speed according to a feedback control process.

[0004] The inventors acknowledge herein that this delayed offset value reduces fuel economy and have endeavored to minimize the use of such offsets. They further acknowledge that idle control and regenerative braking can be combined in a manner described herein to enhance braking by an engine-driven alternator while simultaneously providing idle control with reduced application of the delayed offset ignition timing and faster response time.

[0005] The invention is based on the objective of providing a method that improves the fuel economy of a vehicle with minimal effort.

[0006] According to the invention, the problem is solved by a method according to claim 1 and claim 6.

[0007] In one example, some of the problems mentioned above can be addressed by a procedure that includes: when a motor-driven vehicle is decelerating, charging a battery by means of an alternator driven by the motor; and during engine idle control, when the engine speed is lower than desired, in a first mode reducing the electrical power to selected devices, and in a second mode setting a desired engine ignition timing to a new setting when the engine speed is higher than desired.This improves fuel economy by preventing the creation of a new, delayed setting in an initial operating mode, providing a fast response time by disabling or reducing selected loads, and promoting more regenerative braking during deceleration through battery charging, while reducing it during idle control. Thus, the alternator load can be reduced during a rapid increase in engine torque, provided a certain load exists on the alternator before the required increase in engine torque.

[0008] The selected devices may include those electrical devices which, if deactivated or supplied with reduced electrical power, would not be perceptible to an operator, such devices including one or more of the following: coolant fans, pumps and heaters.

[0009] Another aspect involves increasing the alternator torque during vehicle deceleration to provide additional braking force. Furthermore, idle speed control engages when the vehicle slows to a pre-selected speed.

[0010] In another example, the procedure includes the following: regulating the idle speed of an engine coupled to an alternator that supplies electrical power to various electrical devices in a vehicle driven by the engine; a first mode of engine idle control that is active when a reduction or shutdown of electrical power applied to selected electrical devices would be perceptible to an operator of the vehicle; during the first engine idle control mode, advancing a constant-state ignition timing value of the engine in a retarded direction to an offset retarded value, and if the engine speed is lower than desired, advancing the ignition timing before the offset retarded value, and if the engine speed is higher than desired, retarding the ignition timing beyond the offset retarded value;a second idle control mode, which is active when a reduction or shutdown of electrical power applied to the selected electrical devices would not be perceptible to a vehicle operator; and during the second idle control mode, removal of the offset delayed value and deactivation or reduction of electrical power to the selected devices when the engine speed is lower than desired, and retardation of the ignition timing beyond the permanent state ignition timing value when the engine speed is higher than desired.

[0011] In another example, voltage regulation of the electrical power supplied by the alternator can be provided, with the voltage regulation resulting in a reduction of the alternator's torque in response to the switching off of electrical power applied to the selected electrical devices.

[0012] In another aspect, the target ignition timing corresponds to a permanent ignition timing, and the offset ignition timing is set in such a way that it allows the ignition timing to be advanced without causing ignition knock in the engine.

[0013] It is understood that the above summary is provided to present, in simplified form, a selection of concepts that are further described in the detailed description. It is not intended to identify essential or indispensable features of the claimed subject matter, the scope of which is defined exclusively by the claims following the detailed description. Furthermore, the claimed subject matter is not limited to implementations that resolve any of the disadvantages listed above or in any part of this disclosure. Brief description of the drawings Fig. Figure 1 shows an example of a vehicle system arrangement. Fig. Figure 2 shows an example electrical circuit for the circuit in Fig. 1 vehicle system shown. Fig. Figure 3 shows a schematic flowchart of a procedure for slowing down a vehicle. Fig. Figure 4 shows a flowchart of a procedure for providing braking force to a vehicle using an alternator. The Fig. Figures 5A-5B show flowcharts of a procedure for engine idle speed control. Detailed description

[0014] The following description concerns systems and methods for assisting in decelerating a vehicle and maintaining the engine speed during idle at a value within a desired range of engine speeds. A vehicle system can, as described in Fig. Figure 1 shows an alternator that is mechanically coupled to an engine. In one example, a current and / or voltage can be applied to a field coil of the alternator, which can generate an alternator output current that can then be used to power various electrical loads (e.g., electrical accessories) and charge the battery. In other examples, the conversion of mechanical energy to electrical energy can differ from the conventional alternator field control methods described above. Additionally, because the alternator is mechanically coupled to the engine, the current applied to the alternator's field coil can be configured to match a load applied to the engine.For example, during deceleration of a vehicle, voltage and / or current to the field coil can be increased to provide additional load and braking force for the motor, as in the procedure described in . Fig. 4 is described. Increasing the voltage and / or current to the field coil can also increase the alternator's current output, which in turn can be used to charge a vehicle battery during deceleration. Once the vehicle has decelerated to a threshold and the engine is idling, an engine control unit may be configured to initiate a control procedure, such as the procedure described in the Fig. 5A-5B, to regulate engine speed. During engine idle, unexpected loads can act on the engine and reduce engine speed. To increase engine speed in response to additional engine loads, the engine's throttle valve can be adjusted to allow a greater flow of air to the engine. However, since it can take time for air to travel from the throttle valve to the engine cylinders, there can be a delay in the engine speed response to an increase in intake airflow. Therefore, to provide a faster-acting boost in engine torque, the ignition timing can be advanced to make the engine more efficient. However, advancing the ignition timing beyond a certain threshold can lead to engine knocking and a loss of engine quality.This allows the ignition timing to be retarded by up to an offset value when the engine starts to idle, so that the ignition timing can be advanced without causing engine knocking when additional engine torque is required. Retarding the ignition timing can lead to reduced engine efficiency and thus increased fuel consumption during idling. As in the procedure of the . Fig. As shown in Figures 5A-5B, the alternator can, however, be used under certain engine operating conditions to increase engine torque during idle, thus eliminating the need for an offset ignition timing. Specifically, the voltage and / or current applied to the field coil can be reduced, thereby decreasing the load exerted on the engine by the alternator. Consequently, the engine's fuel efficiency during idle can be improved.

[0015] Fig. Figure 1 shows a block diagram of a vehicle system 10 arrangement, including a vehicle powertrain 20. The powertrain 20 can be supplied with power by the engine 22. In one example, the engine 22 can be a gasoline engine. In alternative examples, other engine configurations, such as a diesel engine, can be used. The engine 22 can be started by an engine starting system 24, which includes a starter motor. In one example, the starter motor can be an electric motor. The starter motor can be configured to assist in restarting the engine at or below a predetermined threshold close to zero, for example, at or below 50 rpm or 100 rpm. The torque of the engine 22 can be adjusted via torque actuators such as a fuel injector 26, throttle valve 25, camshaft (not shown), etc.In particular, the torque of the engine 22 can be regulated by adjusting the amount of intake air flowing to the engine via a position of a throttle valve (not shown), the amount of fuel injected into the engine by the fuel injector 26, and an ignition timing setting.

[0016] Engine output torque can be transmitted to the torque converter 28 to drive an automatic transmission 30. In some examples, the torque converter can be considered part of the transmission. The output power of the torque converter 28 can be controlled by the torque converter lock-up clutch 34. When the torque converter lock-up clutch 34 is fully disengaged, the torque converter 28 transmits torque to the automatic transmission 30 via fluid transfer between the torque converter turbine and the torque converter impeller, thus multiplying the torque. Conversely, when the torque converter lock-up clutch 34 is fully engaged, the engine output torque is transmitted directly through the torque converter 28's clutch to an input shaft (not shown) of the transmission 30.Alternatively, the torque converter lock-up clutch 34 can be partially engaged, thus allowing the amount of torque transmitted to the transmission to be adjusted.

[0017] The torque output of the automatic transmission 30 can in turn be transmitted to the wheels 36 to propel the vehicle. In particular, the automatic transmission 30 can adjust an input drive torque at the input shaft (not shown) in response to a vehicle driving condition before transmitting an output torque to the wheels. For example, transmission torque can be transmitted to the vehicle wheels 36 by engaging one or more clutches, including a forward clutch 32. Thus, a plurality of such clutches can be engaged as needed. Furthermore, the wheels 36 can be locked by engaging wheel brakes 38. In one example, wheel brakes 38 can be engaged in response to the driver pressing their foot on a brake pedal (not shown).In the same way, wheels 36 can be unlocked by releasing wheel brakes 38 in response to the driver lifting his foot from the brake pedal.

[0018] Vehicle system components outside the powertrain may include an alternator 42, a battery 46, and auxiliary loads 48. Electrical auxiliary loads 48 may include lights, a radio system, heating, air conditioning, and ventilation systems (for heating and / or cooling a vehicle interior), seat heating, rear window heating, coolant fans, etc. The alternator 42 may be configured to convert the mechanical energy generated while the motor 22 is running into electrical energy to power the electrical loads 48 and charge the battery 46. The alternator 42 may include a rotor 43 mechanically coupled to the motor 22 and a stator 47 electrically coupled to the battery 46.In a preferred embodiment, the rotor 43 can enclose a rotor field coil 45 which, when electrically excited, induces current to flow in the stator 47 as the rotor 43 rotates relative to the stator 47. In other embodiments, the field coil 45 can be enclosed in the stator 47 instead of the rotor 43. Thus, the output current can be induced in the rotating rotor 43 instead of the stationary stator 47. Therefore, in the preferred embodiment, when a voltage is applied to the field coil 45 and the motor 22 is running, a current can be generated in the stator 47. In one embodiment, current to the field coil 45 can be supplied by the battery 46. In another embodiment, the alternator 42 can include its own DC generator (not shown) to supply current to the field coil 45. The voltage and / or current to the field coil 45 can be regulated by a voltage regulator 44.The voltage regulator can, for example, be a DC-DC converter (or a device based on a DC-DC converter) configured to output a regulated voltage to the field coil 45. In one example, the voltage regulator 44 can be enclosed within the alternator 42. In another example, the voltage regulator 44 can be located outside the alternator 42. Thus, the voltage and / or current to the field coil 45, and therefore the current output of the stator 47, can be regulated by the voltage regulator 44. In one example, a voltage command from a control device 40 can be compared with a battery voltage by the voltage regulator 44. If the voltage command from the control device 40 differs from the battery voltage, the average voltage and / or average current to the field coil 45 can be adjusted to the voltage specified by the control device 40.For example, if the voltage ordered by the control device is greater than the battery voltage, the voltage and / or current applied to the field coil 45 can be increased to increase the current output power of the stator 47. When current is generated in the stator 47, the stator 47 exerts an electromotive force on the rotor 43, which opposes the rotational movement of the rotor 43. Thus, when a voltage is applied to the alternator field coil 45, a load is applied to the motor 22. In another example, decreasing the voltage and / or current applied to the field coil 45 can decrease the current output power of the alternator 42 and decrease the load applied to the motor 22. Therefore, the load applied to the motor 22 can be adjusted by increasing or decreasing the voltage and / or current applied to the field coil 45 of the alternator 42. As below, with reference to the... Fig. 5A and Fig. As discussed in more detail in section 5B, the speed of the motor during idling can be increased by reducing the voltage supplied to the field coil 45.

[0019] In one example, as shown, the motor 22 can be configured to selectively (and automatically) switch off when idle-stop conditions are met and to switch on again when restart conditions are met. One or more auxiliary loads can be maintained at 12 V, for example, even when the motor is switched off. The power to keep the auxiliary loads operational when the motor is switched off can be provided, at least in part, by battery 46.

[0020] The vehicle system 10 can be controlled, at least partially, by a control unit 40 and by input from a vehicle operator 190 via an input device 192. In this example, the input device 192 includes an accelerator pedal and a brake pedal. Additionally, a pedal position sensor 194 is included in the input device 192 to generate a signal of the proportional pedal position PP. The control unit 40 can be a microcomputer comprising: a microprocessor unit, input / output ports, an electronic storage medium for executable programs and calibration values ​​(e.g., a read-only memory chip), working memory, diagnostic memory, and a data bus.The read-only memory, as a storage medium, can be programmed with computer-readable data representing non-volatile instructions executable by the microprocessor to perform the routines described herein, as well as other variations that may be expected but are not specifically listed. The control unit 40 can be configured to receive information from a variety of sensors 65 and to send control signals to a variety of actuators 75 (several examples of which are described herein). Other actuators, such as a variety of additional valves and throttles, can be coupled to various positions in the vehicle system 10.The control unit 40 can receive input data from the various sensors, process the input data, and trigger the actuators in response to the processed input data based on instructions or code programmed therein, corresponding to one or more routines. Exemplary control routines are described herein with reference to the... Fig. 3-5B described.

[0021] As in Fig. As described in section 5, the control device 40 can be configured to vary the voltage or current applied to the alternator's field coil 45, thereby adjusting the mechanical load applied to the engine via the alternator 42 during engine start-up and / or idling. By varying the alternator's field voltage or current, it is possible to change the load the alternator applies to the engine during start-up and / or idling, allowing the alternator load to be varied according to control parameters that are not fundamentally dependent on the engine speed. For example, the alternator's field voltage or current can be adjusted to compensate for engine friction related to engine temperature.Alternatively, the control device 40 can provide the motor with a predictable, consistent volume of mechanical load by essentially maintaining a constant voltage across the alternator's field coil circuit. However, it should be noted that when a constant voltage is applied to the alternator's field coil, the field current and load supplied to the motor by the alternator are not constant. Rather, when a constant voltage is applied to the alternator's field coil, the alternator's field current changes with the rotor's angular velocity. Thus, the current output power of the stator 47 depends on both the voltage and / or current applied to the field coil 45 and the rotational speed of the motor 22. The load applied by the alternator 42 to the motor 22 depends on the voltage and / or current applied to the field coil 45.

[0022] The control device 40 can be configured to receive inputs from the motor 22 and adjust accordingly a mechanical load applied to the motor by the alternator by adjusting the voltage or current supplied by the alternator field coil 45. For example, during engine idling, the control device can adjust the voltage or current supplied to the alternator field coil based on a difference between the actual engine speed and a desired engine speed profile. By adjusting the voltage or current of the field coil 45, the intensity of a magnetic field produced by the field coil 45 in the alternator rotor 43 can be adjusted, making it easier or harder to rotate the rotor 43 of the alternator 42.In this way it is possible to adjust a load applied to a motor 22 via an alternator mechanically coupled to the motor during engine idling, so that the engine speed can be regulated to a desired engine speed.

[0023] The control unit 40 can also adjust engine torque output by adapting a combination of ignition timing (also referred to herein as ignition point), fuel pulse width, fuel pulse rate, and / or air charge by controlling throttle opening and / or valve timing, valve lift, and boost pressure of turbocharged or forced induction engines. In the case of a diesel engine, the control unit 40 can regulate engine torque output by controlling a combination of fuel pulse width, fuel pulse rate, and air charge. In all cases, engine control can be performed cylinder by cylinder to regulate engine torque output.

[0024] If idle-stop conditions are met (e.g., when the vehicle is idling and engine operating parameters are within a desired range), the control unit 40 can selectively switch off the engine by, for example, controlling the operation of the powertrain and / or additional components. Similarly, if engine restart conditions are met, for example, when the vehicle is already idling and one or more engine operating parameters are outside the desired range, the control unit 40 can selectively restart the engine by supplying power to the starter using a battery. Furthermore, the control unit 40 can control engine torque actuators (e.g.,The throttle valve 25 and fuel injector 26) are used, and simultaneously adjustments are made to the current supplied to an alternator field coil 45 to regulate the engine speed during idle. By controlling the engine torque actuators and the load applied to the engine 22 by means of the alternator 42, it may be possible to regulate the engine speed 22 during idle within a desired range.

[0025] If one now turns Fig. 2. A block diagram of an arrangement of an exemplary electrical system of the vehicle system 10 is shown. Fig. 1 shown.

[0026] Components of the in Fig. The vehicle systems 10 shown in the 2 can be the same as those in Fig. The components shown in section 1 must be present. Therefore, the components listed above, referring to... Fig. The components of the vehicle system described in section 10 below will not be discussed in detail. All components described in section 10 will be discussed in more detail below. Fig. The two connection lines shown represent electrical connections. Therefore, all components of the vehicle system 10, which are shown as coupled together, can be directly electrically connected to each other.

[0027] The control unit 40 can be configured to receive information from a variety of sensors 65 and to send control signals to a variety of actuators 75 (several examples of which are described herein). Other actuators, such as a variety of auxiliary valves and throttle valves, can be coupled to various positions in the vehicle system 10. The control unit 40 can communicate electrically with the stator 47, electrical loads 48, and voltage regulator 44. The electrical loads 48 can include auxiliary electrical devices such as pumps, heaters, fans, radios, power steering, etc. In other examples, the control unit 40 can be electrically coupled to the battery 46 and can be powered by the battery 46. In still other examples, the control unit 40 can have its own power source.The voltage regulator 44 can be electrically coupled to the stator 47 of the alternator 42 and the battery 46 to detect the voltage output powers provided by the stator 47 and the battery 46 and to forward the detected voltages to the control device 40. The control device 40 can send signals to the voltage regulator 44 to adjust the voltage and / or current to the alternator field coil 45. In one example, the alternator 42 can include its own excitation circuit 202, which can supply the voltage to the field coil 45. The excitation circuit 202 can be a DC generator or another DC power source. In another example, the voltage for the field coil 45 can be supplied by the battery 46.

[0028] When a motor (e.g., motor 22) is running and voltage is applied to the alternator field coil 45, an alternating magnetic field can be produced by the field coil 45, which can induce a current flow in the stator 47. The stator 47 can include coil windings configured to output current to power the electrical loads 48 and charge the battery 46. During motor operation, the voltage and / or current to the alternator field coil 45 can be modulated by commands from the control unit 40 to the voltage regulator 44, depending on the current requirements of the battery 46 and electrical loads 48.For example, if the control device 40 determines that the current and / or voltage output power of the alternator 42 exceeds the current and / or voltage input from the battery 46 and the electrical loads 48, the control device can signal the voltage regulator 44 to reduce the voltage and / or current to the field coil 45. In another example, if the control device 40 determines that the current output power of the alternator 42 is lower than the current requirements of the electrical loads 48, the control device can signal the voltage regulator to increase the voltage and / or current to the field coil 45. In other words, the voltage regulator 44 can vary the current applied to the field coil 45 to produce a constant voltage in the current output power of the alternator 42.In some examples, the battery 46 can also be used to supplement the electrical output of the alternator 42 if the current demand of the electrical loads 48 is higher than the current output of the alternator 42. In other words, the battery 46 can supply additional electrical power to the electrical loads 48 if their current demand exceeds the current output of the alternator 42. Thus, in some examples, the control device can detect battery current and regulate the current and / or voltage applied to the field coil 45 to maintain a constant state of charge for the battery 46.

[0029] During engine idling, a voltage sufficient to supply all electrical loads 48 of the vehicle system 10 can still be applied to the field coil 45. In other examples, a voltage sufficient to supply all electrical loads 48 and to charge the battery 46 of the vehicle system 10 can be applied to the field coil 45 during engine idling. In still other examples, a voltage sufficient to charge the battery 46, but not sufficient for all electrical loads 48 of the vehicle system 10, can be applied to the field coil 45 during engine idling. In other examples, the current applied to the field coil 45 can drop to near zero during engine idling, and the battery 46 can be used to meet the electrical energy requirements of the electrical loads. As below with reference to the Fig. As discussed in more detail in sections 5A-5B, under certain engine operating conditions at idle, the voltage and / or current to the alternator field coil 45 can be significantly reduced or completely interrupted (e.g., reduced to 0 V), thus reducing the load applied to the engine (e.g., engine 22) by the alternator 42. The control unit 40 can therefore receive signals relating to the state of charge of the battery 46, the power requirements of the electrical loads 48, and the current output power of the stator 47 of the alternator 42. Furthermore, the control unit 40 can estimate and / or measure engine operating conditions based on feedback from a variety of sensors 65.In this way, the control device 40 can adjust the voltage and / or current to the alternator field coil 45 and thus the current output power of the alternator 42 based on engine operating conditions, power requirements of the electrical loads 48 and the state of charge of the battery 46.

[0030] Fig. Figure 3 shows a flowchart of a procedure 300 for entering engine idle during deceleration of a motor vehicle (e.g., vehicle system 10). Instructions for carrying out the procedure 300 can be stored in a memory of an engine control unit such as control unit 40, which is located in the Fig. The data shown in Figures 1-2 can be stored. Furthermore, procedure 300 can be executed by the control unit. Procedure 300 starts at 302, and the control unit (e.g., control unit 40) estimates and / or measures engine operating conditions based on feedback from a variety of sensors (e.g., sensors 65). Engine operating conditions can include engine speed and load, intake air mass flow rate, engine intake pressure, the position of a throttle valve, the position of a brake pedal, engine temperature, etc.

[0031] After estimating and / or measuring engine operating conditions, the control unit can proceed to step 304 and determine whether the throttle angle is lower than a threshold. The threshold can be a predefined threshold angle stored in the control unit's memory. Alternatively, the threshold can be based on a known relationship between the throttle angle, barometric pressure, and air mass flow rate in the vehicle's intake system. Thus, the throttle angle can be used by the control unit to estimate the amount of intake air flowing into the engine (e.g., engine 22). In one example, the throttle valve (e.g., throttle valve 25) may have a valve that regulates the airflow into the engine.If the control unit at 304 determines that the throttle angle is greater than a threshold at 304, the control unit at 310 can proceed and continue engine operation based on engine operating parameters and input from a user (e.g., vehicle operator 190) via an accelerator pedal or brake pedal (e.g., input device 192). Thus, at 310, the control unit can adjust engine operating parameters such as the throttle angle, fuel injection quantity, and alternator load based on input from a user.

[0032] However, if the control unit at 304 determines that the angle of the throttle valve, and thus the amount of intake air flowing to the engine, is lower than a threshold, the control unit can proceed to 306 and determine whether the brake (e.g., the brake pedal of the input device 192) is depressed. The control unit can determine that the brake is applied based on the brake's position as measured by a position sensor (e.g., pedal position sensor 194). In one example, when the brake pedal's position reaches a threshold, the control unit can determine that the brake is applied. In another example, any change in the brake's position when the brake is depressed can be registered by the control unit. If the control unit determines that the brake is not applied, it can proceed to 310 and continue engine operation as discussed above.Procedure 300 can then be resumed from 310. On the other hand, if the control unit determines that the brake at 306 has been applied, procedure 300 can proceed to 308, and the control unit can determine whether the motor speed is below a threshold. The threshold motor speed can be a preset speed stored in the control unit's memory. In other examples, the threshold motor speed can be calibrated by the control unit based on motor operating conditions. The control unit can determine the motor speed using a sensor in the motor, for example, a Hall sensor. If the control unit determines that the motor speed is greater than the threshold motor speed, the control unit can proceed to 310 and continue motor operation as discussed in more detail above.However, if the controller determines that the engine speed is below the threshold engine speed at 308, the controller can proceed to 312 and determine whether the vehicle speed is below a threshold. The threshold at 312 can be a predefined threshold stored in the controller's memory. In other examples, the speed threshold can be a value calibrated by the controller based on engine operating conditions. The controller can estimate the vehicle speed using a sensor, such as a Hall sensor. If the controller determines that the vehicle speed is lower than the threshold value at 312, the procedure 300 to 318 can proceed, and the controller can enter an engine idle control routine as described in more detail with reference to [reference to relevant document]. Fig. 5. In particular, the engine idle control routine can include maintaining the engine speed at a desired speed during engine idling.

[0033] However, if the control unit at 312 determines that the vehicle speed is greater than the threshold, it can deactivate fuel injectors (e.g., fuel injector 26) at 314. Thus, in an effort to slow the vehicle while reducing fuel consumption, the control unit can signal the fuel injectors to stop injecting fuel into the vehicle cylinders. To further assist in slowing the vehicle, the control unit at 314 can proceed to brake energy recuperation at 316, as described below with reference to Fig. 4 is discussed in more detail. In particular, the control device can signal a voltage regulator (e.g., voltage regulator 44) to increase the voltage and / or current to a field coil (e.g., alternator field coil 45) of an alternator (e.g., alternator 42), thus increasing the load applied by the alternator to the engine. The increased load applied to the engine can assist in decelerating the vehicle. Once the control device has completed the brake energy recuperation routine at 316 and the vehicle speed is below a threshold, the process 300 to 318 can proceed, and the control device can transition to engine idle control. Thus, the control device can enter the engine idle control routine directly from 312 when the vehicle speed is below a threshold.However, the control device can proceed to 314 and 316 to reduce the vehicle's speed before entering engine idle control if the vehicle speed at 312 is above the threshold. Then procedure 300 can be resumed.

[0034] It was now on Fig. 4 Reference, in which a flowchart of a procedure 400 for performing a brake energy recovery routine is shown. In particular, the procedure 400 may include applying an additional braking force, besides that of the vehicle brakes (e.g., brakes 38), to the engine (e.g., engine 22) by increasing the alternator torque applied to the engine. Instructions for performing procedure 400 may be stored in a memory of an engine control unit such as the one described in the Fig. The control unit 40 shown in Figures 1-2 can be stored. Furthermore, the procedure 400 can be executed by the control unit. It is important to note that the procedure 400 is based on the control unit as described above. Fig. Procedure 300, discussed in section 3, can be continued. More precisely, procedure 400 can include the brake energy recovery routine discussed in section 316 of procedure 300.

[0035] Procedure 400 begins at 402, and the control unit (e.g., control unit 40) estimates and / or measures engine operating conditions based on feedback from a variety of sensors (e.g., sensors 65). Engine operating conditions may include engine speed and load, intake air mass flow rate, engine intake pressure, a throttle valve position, a brake pedal position, engine temperature, etc. After estimating and / or measuring engine operating conditions at 402, procedure 400 can proceed to 404, and the control unit can determine whether the conditions for brake energy recovery are met. As above, referring to Fig. 3. As discussed in more detail, the conditions for brake energy recovery can include: throttle angle and engine speed below a threshold, vehicle speed above a threshold, application of the vehicle brake by a user, etc. If the control device determines that the conditions for brake energy recovery at 404 are not met, the control device can proceed to 406 and continue engine operation. In particular, the control device can adjust engine operation based on engine operating parameters and input from a vehicle operator (e.g., vehicle operator 190) via a brake pedal and / or accelerator pedal (e.g., input device 192). However, if the control device determines that the conditions for brake energy recovery at 404 are met, the procedure 400 can proceed to 408, and the control device can increase alternator torque and current supplied to a battery (e.g., battery 46).As above, referring to . Fig. As discussed in section 1, a rotor (e.g., rotor 43) of an alternator (e.g., alternator 42) can be mechanically coupled to a motor (e.g., motor 22). Therefore, increasing the alternator torque can increase the load applied by the alternator to the motor and thus provide a braking force for a vehicle system (e.g., vehicle system 10).

[0036] The control device can increase the alternator torque by advancing to one or more optional steps 409 and 411. In one example, the control device can increase the voltage supplied to an alternator field coil (e.g., alternator field coil 45) at 409, thereby increasing the strength of the magnetic field generated by the field coil through the alternator torque. In another example, the control device can increase the setting of a voltage regulator (e.g., voltage regulator 44) at 411. Increasing the setting of the voltage regulator can increase the desired current output power of the alternator. The voltage regulator, in turn, can increase the voltage supplied to the alternator field coil to produce a resulting increase in the alternator's current output power.Thus, the control device can send a signal to the voltage regulator at 408 to increase the voltage and / or current to the alternator field coil. As a result of the increased alternator field coil voltage, the load applied to the engine can increase, thereby slowing the vehicle system, and the alternator's electrical output can increase. The increased electrical output of the alternator at 408 can be directed by the control device to charge the battery. Therefore, method 400 can not only be used to provide braking force to the vehicle by increasing the alternator torque, but it can also be used to charge the battery while the vehicle is decelerating, thus reducing the need to charge the battery during engine idling.

[0037] After increasing the alternator torque and the current supplied to the battery at 408, the control unit can proceed to 412 and determine whether the vehicle speed is below a threshold. The threshold at 412 can be a speed threshold below which the engine is idled, so that torque from the engine is not necessarily transmitted to the wheels (e.g., wheels 36) of the vehicle system. The speed threshold can be predefined and stored in the control unit's memory. In other examples, the speed threshold can be a value calibrated by the control unit based on engine operating conditions. The control unit can estimate the vehicle speed using a sensor, such as a Hall sensor.If the control unit determines that the vehicle speed is not below the threshold at 412, the control unit can return to 408 and increase the alternator torque to the threshold speed in an effort to further decelerate the vehicle. Thus, in one example, the control unit 40 can continue to increase the alternator torque until the vehicle speed is below the threshold value at 412. In other examples, an upper threshold for alternator torque may be predefined and stored in the control unit's memory, so that the alternator torque does not necessarily exceed the upper threshold at 408. If the control unit at 412 determines that the vehicle speed is below the threshold value, the control unit at 414 can, as described below with reference to the... Fig. 5A-5B, which are discussed in more detail, transition to engine idle control. Then procedure 400 can be resumed.

[0038] In the Fig. Figures 5A-5B show flowcharts of a procedure 500 for performing an engine idle speed control routine. During engine idling, the engine speed can be maintained at a preselected speed or within a preselected range of speeds. The ignition timing (also referred to herein as ignition point) can be retarded to reduce the efficiency of the engine (e.g., engine 22), so that if the engine speed drops below the permissible range of engine speeds during idling, the ignition timing can be advanced to increase the engine efficiency and thus increase the engine speed. The ignition timing can be retarded to an offset value during idling because if the ignition timing is advanced beyond a threshold, knocking and engine performance degradation can occur.However, retarding the ignition timing and thus reducing the engine's efficiency leads to an increase in the engine's fuel consumption during idling. Method 500 represents an engine idle speed control that, unlike retarding the ignition timing, can reduce the engine's fuel consumption during idling. In particular, under certain engine operating conditions, Method 500 involves reducing the alternator torque applied to the engine in order to increase the engine speed.

[0039] Instructions for performing procedure 500 may be stored in a memory of an engine control unit such as the one described in the Fig. The control device 40 shown in Figures 1-2 can be stored. Furthermore, the control device can execute procedure 500. Procedure 500 starts at 502, and the control device (e.g., control device 40) estimates and / or measures engine operating conditions based on feedback from a variety of sensors (e.g., sensors 65). Engine operating conditions can include engine speed and load, intake air mass flow rate, engine intake pressure, a throttle valve position, a brake pedal position, engine temperature, etc. After estimating and / or measuring engine operating conditions at 502, procedure 500 can proceed to 504, and the control device can determine whether the conditions for idle control are met. As above, referring to the Fig. 3-4, discussed in more detail, the conditions for idle speed control may include: throttle angle and engine speed below a threshold, vehicle speed below a threshold, application of a vehicle brake by a user, etc.

[0040] If the control unit determines that the conditions for idle control are not met (e.g., that the engine speed is not below a threshold), the control unit can proceed to 506 and continue engine operation. Specifically, at 506, the control unit can adjust engine operation based on engine operating parameters and input from a vehicle operator (e.g., vehicle operator 190) via a brake pedal and / or accelerator pedal (e.g., input device 192). The procedure can then be resumed. However, if the control unit determines at 504 that the conditions for engine idle control are met, the control unit can then determine at 508 whether the state of charge of a battery (e.g., battery 46) is above a threshold. In one example, the control unit can determine the state of charge of the battery via signal outputs from a voltage regulator (e.g.,Voltage regulator 44), which detects, estimates, and / or measures the voltage drop across the battery terminals. The threshold battery charge level can be a predefined threshold stored in the control unit's memory, above which the battery can be fully charged and below which it should be charged. Thus, in one example, if the battery charge is greater than the threshold at 508, the battery does not necessarily have to accept additional current from an alternator (e.g., alternator 42) because it may be fully charged. In other examples, the threshold can represent a battery charge level at which the battery is almost fully charged. If the control unit determines that the battery charge level is not above a threshold, the procedure can be changed to 500 to 540 in . Fig. 5B continue and allow battery charging during idle. Otherwise, if the control unit determines that the battery's state of charge is above a threshold and charging is not necessary, the control unit can deactivate battery charging at 510. Deactivating battery charging may involve reducing or completely stopping the current flow from an alternator (e.g., alternator 42) to the battery. In one embodiment, the control unit can also signal the voltage regulator to apply a voltage to a field coil (e.g., alternator field coil 45) of the alternator sufficient only to power various auxiliary electronics (e.g., electrical loads 48) at 510.Thus, the control device can also reduce the voltage and / or current to a field coil at 510, so that the amount of current output power by the alternator is sufficient to supply power to electrical devices in the vehicle (e.g. vehicle system 10), but is not necessarily sufficient to charge the battery.

[0041] After battery charging is deactivated, the control unit can proceed to step 512 and determine whether an electrical load, also referred to herein as electrical devices (e.g., one of the electrical loads 48), is available for load shedding. In one example, the control unit can determine at step 512 whether a momentary reduction in the current supplied to one or more electrical devices would be imperceptible to a user (e.g., vehicle operator 190). In another example, the control unit can determine at step 512 whether terminating the current flow to one or more electrical devices would be imperceptible to a user. The electrical loads can include one or more auxiliary electronics such as: water pumps, heaters, air conditioners, fans, radios, lights, heated rear windows, heated steering wheels, heated gearshift knobs, heated windshields, etc.For example, a temporary reduction in the power supplied to the heated rear window may go unnoticed by a user.

[0042] In another example, the availability for discarding an electrical load can also be based on the battery's state of charge. For instance, if the battery's state of charge is high, it can be used alongside the alternator as a power source to supply various electrical loads.

[0043] If the controller determines that an electrical load at 512 is not available for discharge, it can then retard the ignition timing at 513 to an offset value. The first offset value can be predefined and stored in the controller's memory and can be based on a known relationship between ignition timing and engine efficiency. In other examples, the offset ignition timing can be calibrated by the controller and based on current engine operating conditions. After retarding the ignition timing at 513, the controller can proceed to 516 and determine whether the engine speed is higher than an upper first threshold. The controller can estimate the engine speed based on feedback from a Hall sensor or another sensor capable of measuring rotational speed.In one example, the upper first threshold could be a predefined engine speed stored in the control unit's memory. This first threshold could represent a maximum desired engine idle speed, above which excessive fuel consumption occurs. In another example, the upper first threshold could be the rate of increase of the engine speed. The control unit can then determine at step 516 whether the rate of increase of the engine speed is above the upper threshold. If the control unit determines that the engine speed at step 516 is above the upper first threshold, it can proceed to step 518 and retard the ignition timing from the first offset value to a second offset value, where the second offset value can be retarded further than the first. The control unit can adjust the ignition timing by sending appropriate signals to spark plugs in the engine cylinders.The control unit can then proceed to step 538 and decrease the throttle angle. Thus, at step 538, the control unit can move the throttle towards a closed position to reduce or stop the airflow to the engine. In one example, the control unit can decrease the angle of a valve positioned in the throttle body (e.g., throttle body 25) to decrease the flow of intake air to the engine. In another example, the valve can be a solenoid valve that can be adjusted based on signals from the control unit. Both decreasing the throttle angle and retarding the ignition timing can each decrease the engine speed. Thus, the control unit can execute steps 518 and 538 to decrease the engine speed. In other examples, the control unit can execute steps 518 and 538 simultaneously.In yet another example, the control device can execute step 518 before executing step 538.

[0044] If the control unit determines at 516 that the engine speed is below the upper first threshold, it can then determine whether the engine speed at 520 is below a lower second threshold. The lower second threshold can be a predefined engine speed stored in the control unit's memory. The second threshold can be lower than the first threshold. Furthermore, in one example, the second threshold could represent a minimum desired engine idle speed below which the engine may stall. In another example, the second threshold could be a rate at which the engine speed decreases. Thus, in yet another example, the control unit can determine at 520 whether the engine speed is decreasing at a rate above the second threshold.If the control unit determines that the engine speed is below the second threshold, it can advance the ignition timing from the first offset value in step 522 and then increase the throttle angle in step 534. Thus, in step 534, the control unit can move the throttle valve towards an open position, thereby increasing airflow to the engine. As discussed above, the throttle angle can be adjusted by modifying a valve located within the throttle valve. Specifically, in step 534, the valve can be moved to an open position. This increases the throttle angle, thereby increasing the amount of air flowing through the engine. The control unit can maintain the increased throttle angle until the engine speed rises above the lower second threshold.Thus, the duration of the increase in throttle angle can be based on the time required for the engine speed to increase above the lower second threshold.

[0045] In one example, the control device can advance the ignition timing back to the same or a very close approximation of step 513 and postpone the retardation to the first offset ignition timing. In other examples, the ignition timing can be advanced to a point retarded beyond the ignition timing of step 513. Furthermore, in one embodiment, the control device can execute steps 522 and 534 simultaneously. In yet other embodiments, the control device can increase the throttle angle at step 534 before advancing the ignition timing in step 522. Advancing the ignition timing and increasing the throttle angle can increase the engine speed.If the control unit determines that the engine speed is above the lower second threshold in step 520, procedure 500 can proceed to step 536, and the control unit can maintain the ignition timing and throttle angle. Thus, if the engine speed is above the lower second threshold, the engine speed can remain within the lower second and upper first thresholds.

[0046] Therefore, the engine speed during idle can be within a desired range of speeds, and thus the control device does not necessarily adjust the ignition timing or throttle angle based on the current ignition timing and throttle angle.

[0047] Returning to step 512, if the control system determines that an electrical load is available for load shedding in step 512, the control system can proceed to step 524 and maintain the current ignition timing. Thus, the engine's efficiency can be maintained during engine idling in step 524. The control system can then proceed to step 526 and determine whether the engine speed is above the upper first threshold. The upper first threshold in step 526 can be the same upper first threshold discussed above in step 516. If it is determined that the engine speed is above the upper first threshold, the control system can proceed to retard the ignition timing in step 528. Specifically, the control system can retard the ignition timing from the ignition timing in step 524.The retarded ignition timing can be similar to the first offset ignition timing discussed above in step 513. In one example, the duration by which the ignition timing is retarded can be predetermined and stored in the control unit's memory. In another example, the duration by which the ignition timing is retarded in step 528 can be based on the engine speed. Thus, the ignition timing can be retarded more as the engine speed rises above the upper first threshold. After retarding the ignition timing in step 528, the control unit can proceed to step 538 and decrease the throttle angle. In other examples, the control unit can execute steps 528 and 538 simultaneously. In still other examples, the control unit can decrease the throttle angle in step 538 before retarding the ignition timing in step 528.

[0048] However, if the control system determines in step 526 that the engine speed is below the upper first threshold, the control system may proceed to step 530 and determine whether the vehicle speed is below the lower second threshold. The lower second threshold in step 530 may be the same lower second threshold discussed above in step 520. If the control system determines in step 520 that the engine speed is above the lower second threshold, procedure 500 may proceed to step 536, and the control system may maintain the ignition timing and throttle angle. Thus, if the engine speed is above the lower second threshold, the engine speed may be within both the lower second and upper first thresholds.Therefore, the engine speed during idle can be within a desired range, and thus the control device does not necessarily adjust the ignition timing or throttle angle based on the current ignition timing and throttle angle. If the control device determines that the engine speed is below the lower second threshold, it can proceed to step 532 and shed an electrical load (e.g., one of the electrical loads 48). Shedding an electrical load in step 532 can involve reducing or completely stopping the current flow to one or more electrical devices. Thus, in one embodiment, the current to one or more electrical loads identified as available for load shedding in step 512 can be reduced.In other examples, the current supplied to the one or more electrical loads identified as available for load shedding in step 512 can be completely interrupted. By reducing the current demand from the electrical loads, a voltage regulator (e.g., voltage regulator 44) can reduce the voltage and / or current to a field coil (e.g., alternator field coil 45) of an alternator (e.g., alternator 42), thus potentially reducing the electrical output power of the alternator. In particular, in one example, the voltage and / or current to the alternator field coil can be reduced to 0 V, so that potentially no voltage is applied to the alternator field coil.In another example, the control unit can determine the extent of the voltage and / or current reduction applied to the alternator field coil based on how much lower the engine speed is than the second threshold. Thus, the control unit can apply larger voltage reductions to the alternator field coil when there is a larger difference between the engine speed and the second threshold. The control unit can also simply signal a voltage regulator (e.g., voltage regulator 44) to reduce the voltage and / or current to the alternator field coil for only a short duration. In particular, the duration of the voltage reduction applied to the alternator field coil in step 532 can be shorter than the duration of the throttle angle increase in step 534. In one example, the duration of the voltage reduction to the alternator field coil can be 0.7 seconds.In other examples, the duration of the voltage drop may be less than 0.7 seconds. In still other examples, the duration of the voltage drop may be more than 0.7 seconds. Reducing the voltage and / or current to the field coil may reduce the torque exerted by the alternator on the engine. Thus, reducing the current to one or more electrical loads in step 532 may provide an immediate or near-immediate reduction in engine load and may thereby increase the engine speed. The control device may then proceed to step 534 and increase the throttle angle. In another example, the control device may execute steps 532 and 534 simultaneously. In still other examples, the control device may execute step 534 before executing step 532.Thus, reducing the voltage and / or current to the alternator field coil in step 532 and increasing the throttle angle can increase the engine speed. The engine speed does not necessarily increase immediately after increasing the throttle angle, as it can take some time for intake air to flow from the throttle valve to the engine cylinders. Therefore, there can be a delay in the increase in engine speed in response to an increase in the throttle angle. To increase the engine speed during this delay between the throttle valve and the engine cylinders, current to one or more electrical loads can be reduced, and consequently, the voltage and / or current to the alternator field coil can also be reduced.Thus, the shedding of the electrical loads in step 532 can provide a near-immediate reduction in the motor load and therefore an increase in the motor speed during the deceleration phase, during which the motor speed does not increase in response to the increased throttle angle in step 534.

[0049] It should also be noted that in other embodiments, the battery control unit can signal the need to supply electrical power to the electrical loads in step 532. Thus, if the alternator's current output decreases in step 532 due to a reduction in the voltage and / or current to the field coil, the control unit does not necessarily have to reduce the current supplied to the electrical loads in step 532. Instead, current can be drawn from the battery to maintain a constant current and / or voltage supply to the electrical loads for the duration of the reduction in voltage supplied to the field coil in step 532.

[0050] If one now turns Fig. 5B to, the above can be in Fig.Procedure 500, discussed in 5A, is continued from step 508. If the control unit determines that the state of charge of a battery is below a threshold in step 508, the control unit can proceed to step 540 and enable charging of the battery. In particular, the control unit can signal the voltage regulator to apply a voltage to the alternator field coil sufficient to generate enough current to both power the electrical loads and charge the battery. Thus, the voltage and / or current to the alternator field coil in step 540 can be greater than the voltage and / or current to the alternator field coil in step 510, at which point battery charging is disabled. Subsequently, the control unit can proceed to step 542 and determine whether the engine speed is above the upper first threshold.The upper first threshold in step 542 may be the same upper first threshold as discussed above for steps 516 and 526. If it is determined that the engine speed is above the upper first threshold, the control device may proceed to retard the ignition timing and decrease the throttle angle in step 544, as discussed above for steps 528 and 538. However, if the engine speed in step 542 is below the upper first threshold, the control device may proceed to step 546 and determine whether the engine speed is below the lower second threshold. The lower second threshold in step 546 may be the same lower second threshold as discussed above for steps 520 and 530.If the control unit determines that the engine speed is above the lower second threshold in step 546, procedure 500 can proceed to step 548, and the control unit can maintain the ignition timing and throttle angle as discussed above for step 536. Thus, if the engine speed is above the lower second threshold, the engine speed can be within the lower second and upper first thresholds. Consequently, the engine speed can be within a desired range of speeds during engine idle, and therefore the control unit does not necessarily adjust the ignition timing or throttle angle based on the current ignition timing and throttle angle.

[0051] If, in step 546, the control unit determines that the engine speed is below the lower second threshold, it can proceed to step 550 and determine whether an electrical load is available for load shedding, as described above in 512. If the control unit determines that no electrical load is available for load shedding, it can proceed to step 552 and reduce the current supplied to the battery by the alternator. In particular, the control unit can signal the voltage regulator to reduce the voltage and / or current to the alternator field coil. This can reduce the alternator's current output power. The voltage and / or current to the field coil must not be reduced below a threshold voltage sufficient to generate enough current in the alternator to power the electrical loads.Due to the reduction in current generated by the alternator, the current to the battery can be reduced. In one example, the current supplied to the battery by the alternator may be completely interrupted at step 552. Consequently, battery charging may end at step 552, and the current generated by the alternator at step 552 may only be sufficient to power auxiliary electronics in the vehicle. The reduction in voltage and / or current to the voltage regulator (e.g., voltage regulator 44) may only last for a relatively short period. In one example, the duration of the voltage drop to the alternator field coil may be 0.7 seconds. In other examples, the duration of the voltage drop may be less than 0.7 seconds. In still other examples, the duration of the voltage drop may be more than 0.7 seconds.Reducing the voltage and / or current to the field coil can reduce the torque exerted by the alternator on the engine. Therefore, diverting the current supplied to the battery in step 552 can provide an immediate or near-immediate reduction in engine load and thus increase engine speed. However, the current to the electrical accessories is not necessarily reduced.

[0052] After reducing the voltage and / or current to the alternator field coil and the current supplied to the battery in step 552, the control unit can proceed to step 556 and increase the throttle angle as discussed above in step 534. The control unit can maintain the increased throttle angle until the engine speed increases above the lower second threshold. Furthermore, the duration of the reduction in voltage and / or current to the alternator field coil and the current supplied to the battery in step 552 can be shorter than the duration of the increase in the throttle angle in step 556.

[0053] If the control unit determines in step 550 that an electrical load is available to be discarded, it can proceed to step 554 and discard an electrical load and / or reduce the current supplied to the battery. Thus, in step 554, the control unit can signal the voltage regulator to reduce the voltage and / or current to the alternator field coil, thereby reducing the alternator's current output and the load exerted on the engine by the alternator. For example, the reduction in voltage and / or current to the alternator field coil can be fixed and stored in the control unit's memory. Specifically, the voltage and / or current to the alternator field coil can be reduced to 0 V, potentially resulting in no voltage being applied to the alternator field coil.In another example, the extent of the reduction in voltage and / or current to the alternator field coil can be determined by the control unit based on how much lower the engine speed is than the second threshold. Thus, the control unit can apply larger voltage reductions to the alternator field coil when there is a larger difference between the engine speed and the second threshold. In response to the reduced alternator output, the control unit can reduce the current to one or more of the battery and auxiliary electrical devices. Reducing the current to the auxiliary electrical devices may involve reducing it to only one or more than one of the electrical devices. Therefore, in some examples, the current is not necessarily reduced for all electrical devices.Furthermore, the current may only be reduced for those devices whose imminent end of use would not be noticed by the user. In other embodiments, however, the current supplied by the alternator to all electrical accessories may be suspended during the reduction of voltage and / or current to the alternator field coil. In one embodiment, the control device can determine, based on the extent of the reduction in voltage and / or current to the alternator field coil, whether current should be reduced to the battery, to the electrical accessories, or to both. Thus, larger reductions in voltage and / or current to the alternator field coil can cause the control device to reduce the current supplied to both the electrical accessories and the battery.In another embodiment, the control device can reduce the current supplied to the battery by the alternator before reducing the current supplied to the electrical devices. In yet another embodiment, the control device can reduce the current supplied to one or more electrical devices before reducing the current supplied to the battery by the alternator. After discarding an electrical load and / or reducing the current supplied to the battery in step 554, the control device can then increase the throttle angle in step 556. In further examples, the control device can perform steps 554 and 556 simultaneously. In still further examples, the control device can increase the throttle angle in step 556 before discarding an electrical load and / or reducing the current supplied to the battery in step 554.It should also be noted that the duration of the reduction of voltage and / or current to the alternator field coil and of the current supplied to the battery in step 552 may be less than the duration of the increase of the throttle angle in step 556.

[0054] Thus, Method 500 can provide for maintaining the engine speed at idle at a desired speed or within a desired range of speeds. Depending on the battery's state of charge, the control device can either enable or disable battery charging during idle. If the battery's state of charge is above a threshold and battery charging during idle is disabled, in a first mode the ignition timing can be retarded beyond a first setpoint to a later, offset second value if electrical loads cannot be discarded without this being perceptible to a user. However, in a second mode, if electrical loads are available for discard without this being perceptible to a user during idle, Method 500 can include not retarding the ignition timing.If the engine speed is above the desired idle speed range, the retarded ignition timing can be further advanced in the first mode, and in the second mode, the ignition timing can be advanced beyond the target value to a further advanced value. If the engine speed is below the desired idle speed range, the ignition timing can be advanced from the second advanced value in the first mode, and in the second mode, one or more electrical loads can be disconnected, thus reducing the voltage and / or current to the alternator coil. If the battery charge level is below a certain threshold and the engine speed is higher than the desired range, the battery can be charged in a third mode, and the ignition timing can be advanced beyond a target value.However, if, in a fourth mode, the battery's state of charge falls below a certain threshold and the engine speed is lower than the desired range, the voltage and / or current to the alternator's field coil can be reduced. Consequently, either battery charging and / or the power supply to electrical loads can be reduced and / or suspended. In other words, the alternator's current output can be reduced in the fourth mode, and therefore the power supplied to either the battery or various electrical devices, or both, can be reduced. Thus, in the fourth mode, if the engine speed is lower than the desired idle speed range, the battery will not necessarily be charged for a certain period of time.

[0055] Therefore, in the first, second, and fourth modes, the battery is not necessarily charged during all or part of the engine idling time. Furthermore, battery charging during idling may only continue for the duration of the engine idling if the battery charge level is below a certain threshold and no electrical loads are available to be shed. Additionally, the ignition timing may only be retarded to an offset value at idle if battery charging is disabled (e.g., if the battery is fully charged) and no electrical load is available to be shed.

[0056] In this way, a method may include: charging a battery by means of an alternator driven by said engine when a motor-driven vehicle is decelerating; and during engine idle control, when the engine speed is lower than desired, in a first mode reducing the electrical power to selected devices, and in a second mode setting a desired engine ignition timing to a new setting when the engine speed is higher than desired. Idle control may commence when the vehicle decelerates to a preselected speed. The method may further include increasing alternator torque during deceleration to provide additional braking force to the vehicle, wherein increasing alternator torque includes increasing the electrical power applied to a rotor field coil of the alternator.The method may further include reducing alternator torque when electrical power to selected devices is reduced in the first mode, wherein reducing alternator torque includes reducing the electrical power applied to a rotor field coil of the alternator. Additionally, the method may include, if the engine speed is higher than desired, retarding the ignition timing beyond the desired engine ignition timing in the first mode, and further retarding the ignition timing beyond the new setting in the second mode. The selected devices may include those electrical devices which, if deactivated or supplied with reduced electrical power, would not be perceptible to an operator, including one or more of the following: coolant fans, pumps, and heaters.The method may further include moving a throttle valve coupled to the engine for controlling the airflow introduced into the engine to a fully open position when the engine speed is lower than desired. The method may further include moving a throttle valve coupled to the engine for controlling the airflow introduced into the engine to a fully closed position when the engine speed is higher than desired.

[0057] In this way, a method can include controlling the idle speed of an engine coupled to an alternator that supplies electrical power to various electrical devices in a vehicle driven by the engine. The method can include a first mode of engine idle control, which is active when a reduction or shutdown of electrical power applied to selected electrical devices would be perceptible to an operator of the vehicle, and, during the first engine idle control mode, advancing a constant-state ignition timing value of the engine in a retarded direction to an offset retarded value, and, if the engine speed is lower than desired, advancing the ignition timing before the offset retarded value, and, if the engine speed is higher than desired, retarding the ignition timing beyond the offset retarded value.The method may additionally include a second mode of engine idle control, which is active when a reduction or shutdown of electrical power applied to the selected electrical devices would not be perceptible to a vehicle operator; and during the second idle control mode, include removing the offset retarded value and disabling or reducing the electrical power to the selected devices when the engine speed is lower than desired, and retarding the ignition timing beyond the constant-state ignition timing value when the engine speed is higher than desired. The method may further include regulating field current in the alternator to control alternator torque and alternator current output power.Field current regulation may include regulating the field current to reduce alternator torque and increase engine torque after switching off the electrical power applied to the selected electrical devices in the second engine idle control mode. The selected electrical devices may include those electrical devices which, if switched off or supplied with reduced electrical power, would not be perceptible to an operator, including one or more of the following: coolant fans, pumps, and heaters.The method may further include moving a throttle valve coupled to the engine for regulating the airflow introduced into the engine to a fully open position when the engine speed is lower than desired, and moving the throttle valve to a closed position when the engine speed is higher than desired. The method may further include charging a vehicle battery with current supplied by the vehicle's alternator when the battery's state of charge falls below a threshold, and conversely, reducing the current supplied to the battery in the first engine idle control mode when the engine speed is lower than desired. Reducing the current supplied to the battery may include reducing alternator torque by reducing the electrical power applied to a rotor field coil of the alternator.

[0058] In this way, a method for decelerating a motor-driven vehicle may include charging a battery by an alternator driven by said motor; initiating idle speed control of the motor when the vehicle has decelerated to a preselected speed; allowing the battery to be charged at idle when the battery's state of charge falls below a threshold; and, during a first operating mode, advancing a target ignition timing of the motor in a retarded direction towards an offset target value, and if the motor speed is lower than desired, advancing the ignition timing before the offset target value, and if the motor speed is higher than desired, retarding the ignition timing beyond the offset target value.The procedure may further include, during the second operating mode, if a reduction in the power applied to selected electrical devices would not be perceptible to a vehicle operator, switching off the electrical power applied to the selected electrical devices when the engine speed is lower than desired, and retarding the engine ignition timing beyond the target ignition timing when the engine speed is higher than desired. The target ignition timing may correspond to a permanent ignition timing, and the offset ignition timing is set such that it allows the ignition timing to be advanced without causing engine knock.The method may further include voltage regulation of the voltage supplied by the alternator, wherein the voltage regulation results in a reduction of the alternator torque and a corresponding increase in the engine torque in response to the disconnection of electrical power applied to the selected electrical devices. The method may further include regulating field current in the alternator to control alternator torque. The method may additionally include increasing alternator torque during deceleration of the vehicle to provide additional braking force to the vehicle, wherein increasing the alternator torque includes increasing the electrical power applied to a rotor winding of the alternator.

[0059] In this way, a method for an engine can include charging a battery while a vehicle decelerates and maintaining the engine speed within a desired range of engine speeds during idling. As a vehicle decelerates, the voltage and / or current to an alternator's field coil can be increased, thereby increasing the alternator torque and, consequently, the load exerted on the engine by the alternator. Thus, a technical effect of providing braking force to a vehicle can be achieved by increasing the voltage and / or current to the alternator while the vehicle is decelerating. Additionally, the alternator's current output power can increase in response to the increase in voltage and / or current to the alternator's field coil.This additional current can be supplied to the battery to charge it while the vehicle decelerates. Thus, increasing the voltage and / or current to an alternator field coil achieves the further technical effect of charging a battery during deceleration. At idle, the engine speed can be maintained within a desired range. In particular, the engine ignition timing can be retarded if the engine speed increases by more than a threshold, thereby reducing engine efficiency and lowering the engine speed. Conversely, if the engine speed drops due to an increase in engine load by more than a threshold, various electrical loads can be discharged to reduce the load applied to the engine by the alternator.

[0060] In other words, if a momentary interruption in the operation of one or more electrical devices would not be noticeable to the user, the power to such devices can be temporarily cut off, and the alternator current can be reduced by reducing the voltage and / or current to the alternator field coil. If the interruption in the operation of at least one of the electrical devices would be noticeable to a user, and if battery charging at idle is disabled, the ignition timing can be retarded to an offset value. The ignition timing can be retarded to the offset value so that, if additional engine torque is required due to a reduction in engine speed at idle, the ignition timing can be advanced without advancing it beyond a point that could cause engine knocking.However, retarding the ignition timing can result in the engine running less efficiently and consuming more fuel than if the ignition timing were not retarded. Therefore, a further technical benefit of increasing fuel efficiency at idle is achieved by not retarding the ignition timing at idle and increasing the voltage and / or current to the alternator field coil when the engine speed drops below a desired range. Thus, by using the alternator, rather than the ignition timing, to add engine torque when the engine speed drops below a desired idle speed range, the engine's fuel consumption at idle can be reduced.In other words, during engine idle, the ignition timing is not delayed, and the alternator torque can be reduced to compensate for drops in engine speed during idle.

[0061] It should be noted that the exemplary control and estimation methods included herein can be used with various engine and / or vehicle system configurations. The control methods and routines disclosed herein can be stored as executable instructions in non-volatile memory and can be executed by the control system, including the control device, in combination with the various sensors, actuators, and other engine hardware. The specific routines described herein can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multi-threaded, and the like. Thus, various actions, operations, and / or functions shown can be performed in parallel in the described sequence or, in some cases, omitted.Accordingly, the processing sequence is not necessarily required to achieve the features and benefits of the exemplary embodiments described herein, but is provided to simplify the presentation and description. One or more of the actions, operations, and / or functions shown may be performed multiple times, depending on the specific strategy used. Furthermore, the described actions, operations, and / or functions can be graphically represented as code to be programmed in the non-volatile memory of the computer-readable storage medium of the motor control system. The described actions are then performed by executing the instructions in a system that includes the various motor hardware components in combination with the electronic control unit.

[0062] It is to be assumed that the configurations and routines disclosed herein are exemplary in nature and that these specific embodiments are not to be considered limiting, as a multitude of variants are possible. For example, the technology described above can be applied to engine types such as V-6, inline-4, inline-6, V-12, four-cylinder boxer engines, and other engine types. The scope of this disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations disclosed herein and other features, functions, and / or characteristics.

[0063] The following claims specifically highlight certain combinations and subcombinations that are considered novel and non-obvious. These claims may refer to "one" element or "a first" element, or its equivalent. Such claims are to be understood as including the combination of one or more such elements, with two or more such elements neither required nor excluded. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by supplementing the present claims or by filing new claims in this or a related application. Such claims are also to be considered included in the subject matter of the present disclosure, regardless of whether they are broader, narrower, equivalent, or different in scope from the original claims.

Claims

[1] Method (300) comprising the following; Rules for the idling of an engine (22) coupled with an alternator (42) which provides electrical power to various electrical devices in a vehicle driven by the engine (22); a first mode of engine idle control which is active when a reduction or shutdown of electrical power applied to the selected electrical devices would be perceptible to an operator of the vehicle; During the first engine idle control mode, a permanent ignition timing value of the engine (22) is advanced in a retardation direction to an offset retarded value, and if the engine speed is lower than desired, the ignition timing is advanced before the offset retarded value, and if the engine speed is higher than desired, the ignition timing is retarded beyond the offset retarded value; a second mode of engine idle control, which is active when a reduction or shutdown of electrical power applied to the selected electrical devices would not be perceptible to a vehicle operator; and During the second idle control mode, the offset delayed value is removed and electrical power for the selected devices is deactivated or reduced when the engine speed is lower than desired, and the ignition timing is delayed beyond the permanent state ignition timing value when the engine speed is higher than desired. [2] Method (300) according to claim 1, further comprising regulating field current in the alternator (42) to control torque of the alternator (42) and current output power of the alternator (42). [3] Method (300) according to claim 1, further comprising moving a throttle valve (25) coupled to the motor (22) for controlling airflow introduced into the motor to a fully open position when the motor speed is lower than desired and moving the throttle valve (25) to a closed position when the motor speed is higher than desired. [4] Method (300) according to claim 1, further comprising charging a battery (46) of the vehicle via current supplied by an alternator (42) of the vehicle when the state of charge of the battery (46) falls below a threshold, and, on the other hand, reducing the current supplied to the battery (46) in the first engine idle control mode when the engine speed is lower than desired. [5] Method (300) according to claim 4, wherein reducing the current supplied to the battery (46) comprises reducing the alternator torque by reducing the electrical power applied to a rotor field coil (45) of the alternator (42). [6] Method (400) comprising the following: When a vehicle powered by a motor (22) slows down, a battery (46) is charged by an alternator (42) which is driven by the motor (22); Initiating idle control of the engine (22) when the vehicle has slowed down to a preselected vehicle speed; Enabling the charging of the battery (46) while idling when the state of charge of the battery (46) falls below a threshold; During a first operating mode, when electrical devices cannot be jettisoned without this being perceptible to an operator of the vehicle, retarding the target ignition timing of the engine (22) in a retarded direction towards an offset target value, and if the engine speed is lower than desired, advancing the ignition timing before the offset target value, and if the engine speed is higher than desired, retarding the ignition timing beyond the offset target value; During a second operating mode, if electrical devices for a drop are available and a reduction in the power applied to selected electrical devices would not be perceptible to an operator of the vehicle, switching off the electrical power applied to the selected electrical devices if the engine speed is lower than desired, and delaying the ignition timing of the engine beyond the target ignition timing if the engine speed is higher than desired. [7] Method (400) according to claim 6, wherein the target ignition timing corresponds to a permanent ignition timing, and the offset ignition timing is set such that it allows the ignition timing to be advanced without causing ignition knock in the engine (22). [8] Method (400) according to claim 6, further comprising a voltage regulation of the voltage provided by the alternator (42), wherein the voltage regulation leads to a reduction of the torque of the alternator (42) and a related increase of the torque provided by the motor (22) in response to the switching off of electrical power applied to the selected electrical devices. [9] Method (400) according to claim 6, further comprising increasing alternator torque during deceleration of the vehicle to provide additional braking force to the vehicle, wherein increasing the alternator torque comprises increasing the electrical power applied to a rotor winding of the alternator (42).

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