Apparatus and method for wheel stability monitoring system

Abstract

The present invention discloses an apparatus and method for a wheel stability monitoring system. A traction control module includes: a sensor / estimation module configured to output wheel stability data based on a plurality of wheel condition inputs; and a wheel stability monitoring module configured to calculate a plurality of wheel stability predictors based on the wheel stability data. Each wheel stability predictor independently indicates a wheel slip condition. The traction control module further includes a wheel stability data fusion module configured to receive each of the plurality of wheel stability predictors, combine selected wheel stability predictors from the plurality of wheel stability predictors to generate a combination of wheel stability predictors, and selectively output a torque reduction request based on the combination of wheel stability predictors.

Description

[0001] The information provided in this section is for the purpose of generally presenting the background of the disclosure. The work of the inventors (to the extent described in this section) and aspects of the specification that were not otherwise prior art at the time of filing are neither explicitly nor implicitly admitted to be prior art to the present disclosure. Technical Field

[0002] The present disclosure relates to vehicle propulsion systems and, more particularly, to traction control systems for monitoring and controlling wheel stability. Background Art

[0003] Some vehicle types include only an internal combustion engine that generates propulsion torque. Electric vehicles may not include an internal combustion engine and may rely on one or more electric motors for propulsion.

[0004] A hybrid vehicle includes both an internal combustion engine and one or more electric motors. Some hybrid vehicle types utilize an electric motor and an internal combustion engine in an attempt to achieve greater fuel efficiency than using only the internal combustion engine. Some hybrid vehicle types utilize an electric motor and an internal combustion engine to achieve greater torque output than the internal combustion engine alone can achieve.

[0005] Some exemplary types of hybrid vehicles include parallel hybrid vehicles, series hybrid vehicles, and other types of hybrid vehicles. In a parallel hybrid vehicle, the electric motor operates in parallel with the engine to combine the power and range advantages of the engine with the efficiency and regenerative braking advantages of the electric motor. In a series hybrid vehicle, the engine drives a generator to generate electricity for the electric motor, and the electric motor drives the transmission. This allows the electric motor to take on some of the power responsibility of the engine, which can allow a smaller and potentially more efficient engine to be used.

[0006] Non-electric, electric, and hybrid vehicles may include traction control systems. Summary of the invention

[0007] The traction control module includes a sensor / estimation module configured to output wheel stability data based on a plurality of wheel condition inputs and a wheel stability monitoring module configured to calculate a plurality of wheel stability predictors based on the wheel stability data. Each wheel stability predictor independently indicates a wheel slip condition. The traction control module further includes a wheel stability data fusion module configured to receive each of the plurality of wheel stability predictors, combine selected wheel stability predictors from the plurality of wheel stability predictors to generate a combination of wheel stability predictors, and selectively output a torque reduction request based on the combination of wheel stability predictors.

[0008] In other features, the plurality of wheel stability predictors corresponds to a plurality of flags, and the wheel stability monitoring module is configured to selectively set the plurality of flags based on the wheel stability data.

[0009] In other features, the plurality of indicia includes a wheel status indicia indicative of wheel slip.

[0010] In other features, the wheel state indicia indicates at least one of a relationship between a wheel speed relative to a longitudinal speed and a slip ratio and a rate of change of torque of the wheel.

[0011] In other features, the plurality of indicia includes wheel acceleration indicia indicative of wheel acceleration.

[0012] In other features, the plurality of indicia includes a slope indicia indicating at least one of a slope of tire longitudinal force with respect to slip ratio and a slope of reaction torque with respect to wheel torque.

[0013] In other features, the plurality of indicia includes a wheel speed phase-portrait indicia that indicates a deviation between a wheel speed slope and a reference slope.

[0014] In other features, the plurality of indicia includes a predictive indicia indicative of a rate of change of a wheel speed slope.

[0015] In other features, the plurality of wheel stability predictors correspond to a plurality of markers, and the plurality of markers include a wheel state marker indicating wheel slip, a slope marker indicating at least one of a slope of tire longitudinal force with respect to slip ratio and a slope of reaction torque with respect to wheel torque, and a wheel speed phase diagram marker indicating a deviation between a wheel speed slope and a reference slope.

[0016] In other features, the wheel stability data fusion module is configured to generate a first output based on a first combination of a slope flag and a wheel state flag, generate a second output based on a second combination of a wheel speed phase diagram flag and a wheel state flag, and generate a detection flag based on a third combination of the first output and the second output, and generate a torque reduction request based on the detection flag.

[0017] In other features, the plurality of markers further include a wheel acceleration marker indicating wheel acceleration and a prediction marker indicating a rate of change of a wheel speed slope, and the wheel stability data fusion module is configured to generate a torque reduction request based on a fourth combination of the detection marker, the wheel acceleration marker, and the prediction marker.

[0018] In other features, the wheel stability data fusion module includes a first logical AND module configured to perform a first combination, a second logical AND module configured to perform a second combination, a first logical OR module configured to perform a third combination, and a second logical OR module configured to perform a fourth combination.

[0019] In other features, a vehicle includes a traction control module.

[0020] A method for determining wheel stability includes outputting wheel stability data based on a plurality of wheel condition inputs and calculating a plurality of wheel stability predictors based on the wheel stability data. Each wheel stability predictor independently indicates a wheel slip condition. The method further includes combining selected wheel stability predictors from the plurality of wheel stability predictors to generate a combination of wheel stability predictors, and selectively outputting a torque reduction request based on the combination of wheel stability predictors.

[0021] In other features, the plurality of wheel stability predictors corresponds to a plurality of markers, and the method further includes selectively setting the plurality of markers based on the wheel stability data.

[0022] In other features, the multiple marks include: a wheel state mark indicating at least one of the relationship between the wheel speed relative to the longitudinal speed and the slip ratio and torque change rate of the wheel, a slope mark indicating at least one of the slope of the tire longitudinal force with respect to the slip ratio and the slope of the reaction torque with respect to the wheel torque, and a wheel speed phase diagram mark indicating the deviation between the wheel speed slope and a reference slope.

[0023] In other features, the method further includes generating a first output based on a first combination of a slope flag and a wheel state flag, generating a second output based on a second combination of a wheel speed phase diagram flag and a wheel state flag, and generating a detection flag based on a third combination of the first output and the second output, and generating a torque reduction request based on the detection flag.

[0024] In other features, the plurality of indicia further includes a wheel acceleration indicia indicating wheel acceleration and a prediction indicia indicating a rate of change of a wheel speed slope.

[0025] In other features, the method further comprises generating a torque reduction request based on a fourth combination of the detection flag, the wheel acceleration flag, and the prediction flag.

[0026] In other features, the method further includes performing the first combination using a first logical AND module, performing the second combination using a second logical AND module, performing the third combination using a first logical OR module, and performing the fourth combination using a second logical OR module.

[0027] The present invention also discloses the following technical solution:

[0028] Solution 1. A traction control module, comprising:

[0029] a sensor / estimation module configured to output wheel stability data based on a plurality of wheel condition inputs;

[0030] a wheel stability monitoring module configured to calculate a plurality of wheel stability predictors based on the wheel stability data, wherein each of the wheel stability predictors independently indicates a wheel slip condition; and

[0031] A wheel stability data fusion module is configured to i) receive each of the plurality of wheel stability predictors, ii) combine selected wheel stability predictors from the plurality of wheel stability predictors to generate the combination of wheel stability predictors, and iii) selectively output a torque reduction request based on the combination of wheel stability predictors.

[0032] Embodiment 2. The traction control module of embodiment 1, wherein the plurality of wheel stability predictors correspond to a plurality of flags, and wherein the wheel stability monitoring module is configured to selectively set the plurality of flags based on the wheel stability data.

[0033] Option 3. The traction control module of Option 2, wherein the plurality of flags includes a wheel status flag indicating wheel slip.

[0034] Embodiment 4. The traction control module of embodiment 3, wherein the wheel state flag indicates at least one of: i) wheel speed relative to longitudinal speed, and ii) a relationship between slip ratio and torque change rate of the wheel.

[0035] Embodiment 5. The traction control module of embodiment 2, wherein the plurality of markers include a wheel acceleration marker indicating wheel acceleration.

[0036] Embodiment 6. The traction control module of embodiment 2, wherein the plurality of indicia includes a slope indicia indicating at least one of: i) a slope of tire longitudinal force with respect to slip ratio, and ii) a slope of reaction torque with respect to wheel torque.

[0037] Embodiment 7. The traction control module of embodiment 2, wherein the plurality of markers include a wheel speed phase diagram marker indicating a deviation between a wheel speed slope and a reference slope.

[0038] Embodiment 8. The traction control module of embodiment 2, wherein the plurality of markers includes a prediction marker indicating a rate of change of a wheel speed slope.

[0039] Embodiment 9. The traction control module of embodiment 1, wherein the plurality of wheel stability predictors correspond to a plurality of markers, and wherein the plurality of markers include:

[0040] wheel status markings indicating wheel slip;

[0041] a slope indicia indicating at least one of: i) a slope of tire longitudinal force with respect to slip ratio, and ii) a slope of reaction torque with respect to wheel torque; and

[0042] Wheel speed phase marker indicating the deviation between the wheel speed slope and the reference slope.

[0043] Solution 10. The traction control module according to Solution 9, wherein the wheel stability data fusion module is configured to:

[0044] i) generating a first output based on a first combination of the slope flag and the wheel state flag, ii) generating a second output based on a second combination of the wheel speed phase diagram flag and the wheel state flag, and iii) generating a detection flag based on a third combination of the first output and the second output; and

[0045] The torque reduction request is generated based on the detection flag.

[0046] Option 11. A traction control module according to Option 10, wherein the plurality of markers further include a wheel acceleration marker indicating wheel acceleration and a prediction marker indicating a rate of change of a wheel speed slope, and wherein the wheel stability data fusion module is configured to generate the torque reduction request based on a fourth combination of the detection marker, the wheel acceleration marker and the prediction marker.

[0047] Solution 12. The traction control module according to Solution 11, wherein the wheel stability data fusion module comprises:

[0048] a first logical AND module configured to perform said first combination;

[0049] a second logical AND module configured to perform said second combination;

[0050] a first logical OR module configured to perform said third combination; and

[0051] A second logical OR module is configured to perform the fourth combination.

[0052] Embodiment 13. A vehicle comprising a traction control module according to Embodiment 1.

[0053] Solution 14. A method for determining wheel stability, the method comprising:

[0054] outputting wheel stability data based on a plurality of wheel condition inputs;

[0055] calculating a plurality of wheel stability predictors based on the wheel stability data, wherein each of the wheel stability predictors independently indicates a wheel slip condition;

[0056] combining selected wheel stability predictors from the plurality of wheel stability predictors to generate the combination of wheel stability predictors; and

[0057] A torque reduction request is selectively output based on the combination of the wheel stability predictors.

[0058] Option 15. The method according to Option 14, wherein the plurality of wheel stability predictors correspond to a plurality of flags, and the method further comprises: selectively setting the plurality of flags based on the wheel stability data.

[0059] Scheme 16. The method according to Scheme 15, wherein the plurality of markers include:

[0060] a wheel state indicia indicating at least one of: i) wheel speed relative to longitudinal speed, and ii) a relationship between slip ratio and rate of change of torque of the wheel;

[0061] a slope indicia indicating at least one of: i) a slope of tire longitudinal force with respect to slip ratio, and ii) a slope of reaction torque with respect to wheel torque; and

[0062] Wheel speed phase marker indicating the deviation between the wheel speed slope and the reference slope.

[0063] Scheme 17. The method according to Scheme 16 further comprises:

[0064] i) generating a first output based on a first combination of the slope flag and the wheel state flag, ii) generating a second output based on a second combination of the wheel speed phase diagram flag and the wheel state flag, and iii) generating a detection flag based on a third combination of the first output and the second output; and

[0065] The torque reduction request is generated based on the detection flag.

[0066] Embodiment 18. The method according to embodiment 17, wherein the plurality of markers further include a wheel acceleration marker indicating wheel acceleration and a prediction marker indicating a rate of change of a wheel speed slope.

[0067] Option 19. The method according to Option 18 further comprises: generating the torque reduction request based on a fourth combination of the detection flag, the wheel acceleration flag and the prediction flag.

[0068] Scheme 20. The method according to Scheme 19 further comprises:

[0069] performing the first combination using a first logical AND module;

[0070] performing the second combination using a second logical AND module;

[0071] performing the third combination using a first logical OR module; and

[0072] The fourth combination is performed using a second logical OR module.

[0073] Other aspects of the application of the present disclosure will be apparent from the detailed description, claims, and drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] The present disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0075] Figure 1 is a functional block diagram of an exemplary vehicle system;

[0076] Figure 2 is a functional block diagram of an exemplary propulsion control system;

[0077] Figure 3 is a functional block diagram of an exemplary traction control module;

[0078] Figure 4A shows the slope based on the slip ratio;

[0079] Figure 4B showing the slope based on wheel torque;

[0080] Figure 4C showing a deviation between a wheel speed slope and a reference slope;

[0081] Figure 5 is a functional block diagram of an exemplary wheel stability data fusion module; and

[0082] Figure 6The steps of an exemplary method for determining wheel stability are shown, where Y is "yes" and N is "no".

[0083] In the drawings, reference numerals may be repeated to refer to similar and / or identical elements. DETAILED DESCRIPTION

[0084] The internal combustion engine of a vehicle burns air and fuel in cylinders to produce propulsion torque. The engine can output torque to the wheels of the vehicle via a transmission. Some vehicle types may not include an internal combustion engine or the internal combustion engine may not be mechanically coupled to the vehicle's powertrain.

[0085] The electric motor may be mechanically coupled to a shaft of the transmission. In some cases, a control module of the vehicle may apply power from a battery to the electric motor in order to cause the electric motor to output torque for vehicle propulsion. In other cases, the control module may disable the flow of power to the electric motor and allow the transmission to drive the rotation of the electric motor. The electric motor generates electricity when driven by the transmission. When the voltage generated via the electric motor is greater than the voltage of the battery, the electricity generated by the electric motor can be used to recharge the battery. The control module switches one or more switches of the inverter module in order to apply power from the battery to the electric motor.

[0086] A vehicle according to the present disclosure includes a traction control system that monitors wheel stability and accurately predicts wheel behavior. For example, the traction control system monitors multiple conditions indicative of wheel stability and utilizes the multiple monitored conditions to predict wheel behavior.

[0087] Reference now Figure 1 , a functional block diagram of an exemplary vehicle system 100 is presented. Although the vehicle system 100 for a hybrid vehicle 104 is shown and will be described, the present disclosure is also applicable to non-electric vehicles, electric vehicles that do not include an internal combustion engine, fuel cell vehicles, autonomous vehicles, and other types of vehicles. In addition, although an example of a vehicle 104 is provided, the present application is also applicable to non-vehicle embodiments.

[0088] The engine 108 may combust an air / fuel mixture to produce drive torque. An engine control module (ECM) 112 controls the engine 108. For example, the ECM 112 may control actuation of engine actuators such as a throttle valve, one or more spark plugs, one or more fuel injectors, valve actuators, camshaft phasers, exhaust gas recirculation (EGR) valves, one or more boost devices, and other suitable engine actuators. In some vehicle types (e.g., electric vehicles), the engine 108 may be omitted.

[0089] The engine 108 may output torque to the transmission 116. A transmission control module (TCM) 120 controls operation of the transmission 116. For example, the TCM 120 may control gear selection and one or more torque-transmitting devices (eg, a torque converter, one or more clutches, etc.) within the transmission 116.

[0090] The vehicle system 100 includes one or more electric motors, such as the electric motor 124. The electric motor can be used as a generator or as a motor at a given moment. When used as a generator, the electric motor converts mechanical energy into electrical energy. The electrical energy can be used, for example, to charge the battery 128. When used as a motor, the electric motor generates torque that can be used, for example, for vehicle propulsion. Although an example of an electric motor is provided, a vehicle can include more than one electric motor.

[0091] The motor control module 132 controls the flow of power from the battery 128 to the electric motor 124 and from the electric motor 124 to the battery 128. The motor control module 132 applies power from the battery 128 to the electric motor 124 to cause the electric motor 124 to output positive torque, such as for vehicle propulsion. For example, the motor control module 132 controls the switching of switches of the inverter module 134. The battery 128 may include, for example, one or more cells and / or battery packs.

[0092] The electric motor 124 can output torque to, for example, an input shaft of the transmission 116 or an output shaft of the transmission 116. The clutch 136 can be engaged to couple the electric motor 124 to the transmission 116 and disengaged to decouple the electric motor 124 from the transmission 116. One or more gearing devices can be employed between the output of the clutch 136 and the input of the transmission 116 to provide a predetermined ratio between the rotation of the electric motor 124 and the rotation of the input of the transmission 116.

[0093] The motor control module 132 can also selectively convert the mechanical energy of the vehicle into electrical energy. More specifically, when the electric motor 124 is driven by the transmission 116 and the motor control module 132 is not applying power from the battery 128 to the electric motor 124, the electric motor 124 generates and outputs power via back EMF. The motor control module 132 can charge the battery 128 via the power output by the electric motor 124.

[0094] The ECM 112 may implement a traction control system according to the principles of the present disclosure. Figure 1148; described in more detail below). For example, the ECM 112 receives various wheel condition inputs 140 (i.e., inputs indicative of wheel stability), such as measurements from corresponding sensors 144 (e.g., wheel speed sensors configured to measure corresponding rotational speeds of wheels 148). The wheel condition inputs 140 may include estimates, calculations, etc., including but not limited to wheel speed, wheel acceleration, drive torque, longitudinal acceleration, yaw rate, and vehicle longitudinal speed.

[0095] Reference now Figure 2 , a functional block diagram of an exemplary propulsion control system 200 including an ECM 112 according to the present disclosure is shown. The ECM 112 includes a driver torque module 204 that determines a driver torque request 208 based on a driver input 212. The driver input 212 may include, for example, an accelerator pedal position (APP), a brake pedal position (BPP), a cruise control input, and / or an autonomous input. In various implementations, the cruise control input may be provided by an adaptive cruise control system that attempts to maintain at least a predetermined distance between the vehicle 104 and an object in the path of the vehicle 104. The autonomous input may be provided by an autonomous driving system that controls the movement of the vehicle 104 from one location to another while avoiding objects and other vehicles. For example, the driver torque module 204 determines the driver torque request 208 based on one or more lookup tables that associate driver inputs with driver torque requests. The APP and BPP may be measured using one or more APP sensors and BPP sensors, respectively.

[0096] The driver torque request 208 may be an axle torque request. Axle torque (including axle torque requests) refers to torque at the wheels 148. As discussed further below, propulsion torque (including propulsion torque requests) differs from axle torque in that propulsion torque may refer to torque at a transmission input shaft.

[0097] The axle torque arbitration module 216 arbitrates between the driver torque request 208 and other axle torque requests 220. Axle torque (torque at the wheels) can be generated by various sources including the engine 108 and / or one or more electric motors (such as the electric motor 124). Other examples of axle torque requests 220 include, but are not limited to, torque reductions requested by a traction control system or module 222 when positive wheel slip is detected, torque increase requests to offset negative wheel slip, brake management requests to reduce axle torque to ensure that axle torque does not exceed the ability of the brakes to hold the vehicle when the vehicle is stopped, and vehicle overspeed torque requests to reduce axle torque to prevent the vehicle from exceeding a predetermined speed. The traction control module 222 according to the present disclosure monitors wheel stability and accurately predicts wheel behavior by monitoring multiple conditions (e.g., wheel condition inputs 140) that indicate wheel stability, as described in more detail below. The axle torque arbitration module 216 outputs one or more axle torque requests 224 based on the results of the arbitration between the received axle torque requests 208 and 220.

[0098] In a hybrid vehicle, a hybrid module 228 can determine how much of the one or more axle torque requests 224 the engine 108 should generate and how much of the one or more axle torque requests 224 the electric motor 124 should generate. For simplicity, the example of the electric motor 124 will continue, although multiple electric motors may be used. The hybrid module 228 outputs one or more engine torque requests 232 to a propulsion torque arbitration module 236. The engine torque request 232 indicates a requested torque output of the engine 108.

[0099] The hybrid module 228 also outputs a motor torque request 234 to the motor control module 132. The motor torque request 234 indicates a requested torque output (positive or negative) of the electric motor 124. In a vehicle where the engine 108 is omitted (e.g., an electric vehicle) or is not connected to output propulsion torque for the vehicle, the axle torque arbitration module 216 may output an axle torque request and the motor torque request 234 may be equal to the axle torque request. In the example of an electric vehicle, the ECM 112 may be omitted, and the driver torque module 204 and the axle torque arbitration module 216 may be implemented in the motor control module 132.

[0100] In an electric vehicle, the driver torque module 204 may input the driver torque request 208 to the motor control module 132 and components related to controlling engine actuators may be omitted.

[0101] The propulsion torque arbitration module 236 converts the engine torque request 232 from the axle torque domain (torque at the wheels) into the propulsion torque domain (e.g., torque at the input shaft of the transmission). The propulsion torque arbitration module 236 arbitrates the converted torque request with other propulsion torque requests 240. Examples of other propulsion torque requests 240 include, but are not limited to, torque reductions for engine overspeed protection requests and torque increases for stall prevention requests. The propulsion torque arbitration module 236 may output one or more propulsion torque requests 244 as arbitration results.

[0102] The actuator control module 248 controls actuators 252 of the engine 108 based on the propulsion torque request 244. For example, based on the propulsion torque request 244, the actuator control module 248 may control opening of a throttle valve, timing of spark provided by a spark plug, timing and amount of fuel injected by a fuel injector, cylinder activation / deactivation, intake and exhaust valve phasing, output of one or more boost devices (e.g., a turbocharger, a supercharger, etc.), opening of an EGR valve, and / or one or more other engine actuators. In various implementations, the propulsion torque request 244 may be adjusted or modified before being used by the actuator control module 248, such as to create a torque reserve.

[0103] The motor control module 132 controls the switching of switches of the inverter module 134 based on the motor torque request 234. The switching of the inverter module 134 controls the flow of power from the battery 128 to the electric motor 124. Therefore, the switching of the inverter module 134 controls the torque of the electric motor 124. The inverter module 134 also converts the power generated by the electric motor 124 and outputs the power to the battery 128, for example, to charge the battery 128.

[0104] Figure 3 An exemplary traction control module 300 (eg, corresponding to Figure 2 The traction control module 300 includes a sensor / estimation module 304. The sensor / estimation module receives wheel condition inputs 140, which may include direct measurements from corresponding sensors 144 and data for estimating and / or calculating values ​​indicative of wheel stability. For example, the direct measurements may include measurements of wheel speeds, and the calculated values ​​may include wheel accelerations. The sensor / estimation module 304 outputs wheel stability data 308 based on the sensed and calculated values. The wheel stability data 308 includes, but is not limited to, wheel speeds, wheel accelerations, drive torque, longitudinal acceleration, and vehicle speed.

[0105] The wheel stability monitoring module 312 receives the wheel stability data 308 and calculates and outputs a plurality of wheel stability predictors 316 based on the wheel stability data 308. For example, the wheel stability monitoring module 312 calculates three or more of the wheel stability predictors 316. Each of the wheel stability predictors 316 can independently indicate a wheel slip condition, as described in more detail below. For example, the wheel stability predictor 316 is a corresponding flag that can be optimally set based on the wheel stability data 308 (e.g., a binary flag having a "0" state if the corresponding stability data 308 does not indicate wheel slip, or a "1" state if wheel slip is indicated). The wheel stability predictor 316 includes, but is not limited to, a slip ratio slope flag, one or more wheel state flags, and a wheel speed phase diagram flag. In some examples, the wheel stability predictor 316 includes a road condition flag (e.g., a flag that is selectively set when known road conditions meet one or more criteria).

[0106] The wheel stability data fusion module 320 receives the wheel stability predictors 316 and selectively indicates whether wheel slip is detected based on the wheel stability predictors 316. For example, in response to a determination that a combination of the wheel stability predictors 316 indicates that wheel slip is detected, the wheel stability data fusion module 320 outputs a torque reduction request (e.g., as one of the axle torque requests 220), as described in more detail below.

[0107] Figure 4A The slip ratio 400 is shown as a function of longitudinal force (N) (e.g., tire longitudinal force). For example, the slip ratio corresponds to the difference between the calculated forward speed of the vehicle 104 (e.g., as expected, based on the rotating wheel speed) and the actual speed of the vehicle 104. The slip ratio slope is greater than zero in the first region 404 ( ), is less than or equal to zero in the second region 408 ( or <0). A positive slip ratio slope (i.e., in the first region 404) indicates satisfactory wheel stability. Conversely, a zero or negative slip ratio slope (i.e., in the second region 408) may indicate wheel instability. Therefore, the wheel stability monitoring module 312 may monitor the slip ratio and set the slip ratio slope flag in response to a determination that the slip ratio slope is transitioning from the first region 404 to the second region 408 (e.g., at 412).

[0108] In some examples, the wheel stability monitoring module 312 may also be configured as follows: Figure 4BThe wheel torque 416 is shown monitored and the wheel torque slope flag is selectively set accordingly. The wheel torque 416 is shown as a function of the reaction torque (e.g., the estimated tire rotational force transmitted to the ground in Nm). The wheel torque slope is positive and is generally linear in the first region 420 and non-linear in the second region 424. A linear vehicle torque slope (i.e., in the first region 420) indicates satisfactory wheel stability. Conversely, a non-linear wheel torque slope (i.e., in the second region 424) may indicate wheel instability. Therefore, the wheel stability monitoring module 312 may monitor the wheel torque and set the wheel torque slope flag in response to a determination that the wheel torque slope is transitioning from the first region 420 to the second region 424 (e.g., at 428).

[0109] In this way, the wheel stability monitoring module 312 can selectively set one or both of the slip ratio slope flag and the wheel torque slope flag. In some examples, in response to a determination that either the slip ratio slope flag and the wheel torque slope flag are set, the wheel stability monitoring module 312 can set a single slope flag (e.g., the slope flag can be set based on a logical OR combination of the slip ratio slope flag and the wheel torque slope flag). In other words, in response to a determination that either of the following: (i) the slip ratio slope is transitioning from the first region 404 to the second region 408, and (ii) the wheel torque slope is transitioning from the first region 420 to the second region 424, the wheel stability monitoring module 312 can set the slope flag.

[0110] The one or more wheel state flags may include, but are not limited to, a wheel acceleration flag, a relative wheel speed flag, and a slip-torque change flag. For example, in response to a determination that the wheel acceleration exceeds a predetermined wheel acceleration threshold (e.g., a calibrated wheel acceleration threshold indicating wheel slip), the wheel stability monitoring module 312 may set the wheel acceleration flag. In an example, in response to a determination that the wheel acceleration flag is set, the wheel stability monitoring module 312 may set the wheel state flag.

[0111] The relative wheel speed may correspond to a difference between a rotational speed of the wheel and a longitudinal speed of the wheel (e.g., measured or estimated at a location such as a wheel hub). In response to a determination that the relative wheel speed exceeds a predetermined relative wheel threshold (e.g., a calibrated relative wheel speed threshold indicating wheel slip), the wheel stability monitoring module 312 may set a relative wheel speed flag.

[0112] The slip-torque variation may correspond to a relationship between a slip ratio and a torque change rate. For example, the slip ratio and the torque change rate may increase correspondingly in a substantially linear manner. The difference between the slip ratio and the torque change rate may be constant or substantially linear. In response to a determination that the difference between the slip ratio and the torque change rate exceeds a predetermined slip-torque variation threshold (e.g., a calibrated slip-torque variation threshold indicating wheel slip), the wheel stability monitoring module 312 may set a slip-torque variation flag.

[0113] In an example, in response to a determination that both the relative wheel speed flag and the slip-torque variation flag are set, the wheel stability monitoring module 312 may set a wheel state flag (eg, the wheel state flag may be set based on a logical AND combination of the relative wheel speed flag and the slip-torque variation flag).

[0114] like Figure 4C As shown, the wheel stability monitoring module 312 may set a wheel speed phase diagram flag based on a deviation between a calculated slope 432 of a wheel speed 436 (e.g., shown as an equivalent rotational wheel speed relative to a longitudinal wheel speed at a wheel hub) and a reference slope 440. For example, the reference slope 440 may correspond to a slope of the wheel speed 436 while wheel stability is satisfactory (e.g., a slope predicted or calibrated during normal operating conditions). The wheel stability monitoring module 312 monitors the slope 432 and determines whether a difference (e.g., a deviation angle 444) between the slope 432 and the reference slope 440 exceeds a predetermined deviation threshold (e.g., a calibrated deviation threshold indicating wheel slip). In response to a determination that the deviation angle 444 exceeds the predetermined deviation threshold, the wheel stability monitoring module 312 sets the wheel speed phase diagram flag.

[0115] In some examples, the wheel stability monitoring module 312 may predict the wheel state based on a change in the slope 432. For example, as the slope 432 begins to deviate from the reference slope 440, the wheel stability monitoring module 312 calculates a rate of change of the slope 432. If the rate of change of the slope 432 exceeds a predetermined rate of change, the wheel stability monitoring module 312 may set a predicted wheel slip flag.

[0116] Reference now Figure 5, an exemplary wheel stability data fusion module 500 (e.g., corresponding to the wheel stability data fusion module 320) is shown. The wheel stability data fusion module 500 receives a flag (as the wheel stability predictor 316) and selectively outputs a wheel instability flag 504 based on the flag. For example, the wheel stability data fusion module 500 combines or fuses the flags output by the wheel stability monitoring module 312 to selectively set the wheel instability flag 504. The wheel instability flag 504 may correspond to a torque reduction request. As shown, the wheel stability data fusion module 500 is implemented as one or more logic circuits or modules. In other examples, the wheel stability data fusion module 500 may include a processor that executes software corresponding to the logic module. In some examples, the wheel stability data fusion module 500 may be configured to perform other appropriate data fusion processing, such as a Kalman filter, a membership function, etc.

[0117] The logic AND circuit or module 508 receives the slope flag and the wheel state flag. Therefore, the output of the logic AND module 508 indicates whether both the slope flag and the wheel state flag are set. Similarly, the logic AND circuit or module 512 receives the wheel speed phase diagram flag and the wheel state flag. Therefore, the output of the logic AND module 512 indicates whether both the wheel speed phase diagram flag and the wheel state flag are set. In this way, the logic AND modules 508 and 512 reduce the false alarms that may occur when only one of the slope flag, the wheel state flag and the wheel speed phase diagram flag is set. Conversely, the logic OR circuit or module 516 receives the corresponding outputs of the logic AND modules 508 and 512 and outputs a detection flag (e.g., a fused detection flag) 520 accordingly. In other words, if (i) both the slope flag and the wheel state flag are set, or (ii) both the wheel speed phase diagram flag and the wheel state flag are set, the logic OR module 516 sets the detection flag.

[0118] The logic OR circuit or module 524 receives the detection flag 520, the predicted wheel slip flag, and the wheel acceleration flag. Therefore, the output of the logic OR circuit (i.e., the wheel instability flag 504) indicates whether any one of the detection flag 520, the predicted wheel slip flag, and the wheel acceleration flag is set. The outputs of the logic AND modules 508 and 512 and the logic OR modules 516 and 524 correspond to the combination of the wheel stability predictors 316 (i.e., the corresponding flags) that independently indicate a wheel slip condition. In other words, the wheel stability data fusion module 500 fuses the data corresponding to the respective wheel stability predictors 316 to generate a wheel instability flag.

[0119] Figure 6Steps of an exemplary method 600 for determining wheel stability are shown. At 604, the method 600 (e.g., the sensor / estimation module 304) receives wheel condition inputs and outputs wheel stability data based on the wheel condition inputs. At 608, the method 600 (e.g., the wheel stability monitoring module 312) receives the wheel stability data and selectively sets one or more flags indicative of wheel stability based on the wheel stability data. For example, the method 600 selectively sets flags including, but not limited to, wheel state flags, slope flags, wheel speed phase diagram flags, predicted wheel slip flags, and wheel acceleration flags.

[0120] At 612, the method 600 (e.g., the wheel stability data fusion module 320) determines whether the wheel acceleration flag is set. If true, the method 600 continues to 616. If false, the method 600 continues to 620. At 616, the method 600 (e.g., the wheel stability data fusion module 320) outputs a wheel instability flag (e.g., corresponding to a torque reduction request).

[0121] At 620 , the method 600 (eg, the wheel stability data fusion module 320 ) determines whether the predicted wheel slip flag is set. If true, the method 600 continues to 616 and outputs a wheel instability flag. If false, the method 600 continues to 624 .

[0122] At 624, the method 600 (e.g., the wheel stability data fusion module 320) determines whether a detection flag is set. For example, the method 600 determines whether any of the following: (i) the slope flag and the wheel state flag are set, or (ii) the wheel speed phase diagram flag and the wheel state flag are set. If true, the method 600 (e.g., the wheel stability data fusion module 320) continues to 616 and outputs a wheel instability flag. For example, the method 600 sets the detection flag and outputs the wheel instability flag in response to the detection flag being set. If false, the method 600 continues to 604.

[0123] If method 600 outputs a wheel instability flag at 616 , method 600 continues to 628 . At 628 , method 600 (eg, the axle torque arbitration module 216 ) generates a torque request to adjust vehicle torque based on the wheel instability flag and continues to 604 .

[0124] The above description is essentially illustrative only and does not attempt to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in various forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be limited thereto, because once the drawings, descriptions and appended claims are studied, other modifications will become apparent. It should be understood that one or more steps in the method can be performed in different orders (or simultaneously) without changing the principles of the present disclosure. Further, although each embodiment is described above as having certain features, any one or more of these features described in any embodiment of the present disclosure can be implemented in any of the other embodiments and / or in combination with the features of any of the other embodiments, even if such a combination is not explicitly described. In other words, the embodiments are not mutually exclusive, and the replacement of one or more embodiments with each other falls within the scope of the present disclosure.

[0125] Various terms, including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "positioned," are used to describe spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.). Unless explicitly described as "directly," when describing a relationship between a first and a second element in the above disclosure, the relationship can be a direct relationship with no other intervening elements between the first and second elements, but can also be an indirect relationship with one or more intervening elements (spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical OR, and should not be construed to mean "at least one of A, at least one of B, and at least one of C."

[0126] In the drawings, the direction of the arrow, as shown by the arrow, generally indicates the flow of information (such as data or instructions) of interest to the illustration. For example, when component A and component B exchange various information, but the information transmitted from the component to component B is relevant to the illustration, the arrow may point from the component to component B. This unidirectional arrow does not imply that no other information is transmitted from component B to component A. Further, for information sent from component A to component B, component B may send an information request to component A or receive an information confirmation.

[0127] In this application, including the following definitions, the term "circuit" may be used instead of the term "module" or the term "controller". The term "module" may refer to a portion of or include an application specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or grouped) that executes code; a memory circuit (shared, dedicated, or grouped) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system on a chip.

[0128] The module may include one or more interface circuits. In some examples, the interface circuit may include a wired or wireless interface connected to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functionality of any given module of the present disclosure may be distributed among multiple modules connected via the interface circuits. For example, multiple modules may allow for load balancing. In further examples, a server (also referred to as a remote or cloud) module may perform some functions on behalf of a client module.

[0129] The term code used above may include software, firmware and / or microcode, and may refer to programs, routines, functions, classes, data structures and / or objects. The term shared processor circuit includes a single processor circuit that executes some or all of the code from multiple modules. The term grouped processor circuit includes a processor circuit that is combined with additional processor circuits to execute some or all of the code from one or more modules. Reference to multiple processor circuits includes multiple processor circuits on discrete chips, multiple processor circuits on a single chip, multiple cores of a single processor circuit, multithreading of a single processor circuit, or a combination of the above. The term shared memory circuit includes a single memory circuit that stores some or all of the code from multiple modules. The term grouped memory circuit includes a memory circuit that is combined with additional memory to store some or all of the code from one or more modules.

[0130] The term memory circuit is a subset of the term computer-readable medium. The term computer-readable medium as used herein does not include transient electronic or electromagnetic signals propagated through a medium (e.g., on a carrier wave); the term computer-readable medium may therefore be considered tangible and non-transient. Non-limiting examples of non-transient tangible computer-readable media are non-volatile memory circuits (e.g., flash memory circuits, erasable programmable read-only memory circuits, or mask read-only memory circuits), volatile memory circuits (e.g., static random access memory circuits or dynamic random access memory circuits), magnetic storage media (e.g., analog or digital tapes or hard drives), and optical storage media (e.g., CDs, DVDs, or Blu-ray discs).

[0131] A special-purpose computer can be produced by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program, thereby partially or completely implementing the devices and methods described in this application. The above-mentioned function blocks, flow chart components and other elements are used as software descriptions, which can be converted into computer programs through routine work of technicians or programmers.

[0132] The computer program includes processor executable instructions stored on at least one non-transitory tangible computer readable medium. The computer program may also include or rely on stored data. The computer program may include a basic input / output system (BIOS) that interacts with the hardware of the special-purpose computer, device drivers that interact with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0133] A computer program may include: (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language), XML (Extensible Markup Language), or JSON (Javascript Object Notation), (ii) assembly code, (iii) object code generated by a compiler from a source code, (iv) source code executed by a translator, (v) source code compiled and executed by a just-in-time compiler, etc. By way of example only, the source code may be written using syntax formed by languages ​​including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor Language), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.

Claims

1. A traction control module, comprising: a sensor / estimation module configured to output wheel stability data based on a plurality of wheel condition inputs; a wheel stability monitoring module configured to calculate a plurality of wheel stability predictors based on the wheel stability data, wherein each of the wheel stability predictors independently indicates a wheel slip condition; and a wheel stability data fusion module configured to i) receive each of the plurality of wheel stability predictors, ii) combine selected wheel stability predictors from the plurality of wheel stability predictors to generate the combination of wheel stability predictors, and iii) selectively output a torque reduction request based on the combination of wheel stability predictors, wherein the plurality of wheel stability predictors correspond to a plurality of flags, and wherein the wheel stability monitoring module is configured to selectively set the plurality of flags based on the wheel stability data, and Wherein, the plurality of indicia include a slope indicia indicating at least one of: i) a slope of tire longitudinal force with respect to slip ratio, and ii) a slope of reaction torque with respect to wheel torque, wherein the reaction torque is an estimated tire rotational force transmitted to the ground.

2. The traction control module of claim 1, wherein: The plurality of indicia also includes a wheel status indicia indicating wheel slip.

3. The traction control module of claim 2, wherein: The wheel state indicia indicates at least one of: i) wheel speed relative to longitudinal speed, and ii) a relationship between a slip ratio and a rate of change of torque of the wheel.

4. The traction control module of claim 1 , wherein: The plurality of indicia further includes a wheel acceleration indicia indicating wheel acceleration.

5. The traction control module of claim 1 , wherein: The plurality of indicia further includes a wheel speed phase diagram indicia indicating a deviation between a wheel speed slope and a reference slope.

6. The traction control module of claim 1, wherein: The plurality of indicia also includes a predictive indicia indicative of a rate of change of a wheel speed slope.

7. The traction control module of claim 1 , wherein: The plurality of wheel stability predictors corresponds to a plurality of markers, and wherein the plurality of markers comprises: wheel status markings indicating wheel slip; a slope indicia indicating at least one of: i) a slope of tire longitudinal force with respect to slip ratio, and ii) a slope of reaction torque with respect to wheel torque; and Wheel speed phase marker indicating the deviation between the wheel speed slope and the reference slope.

8. The traction control module of claim 7, wherein: The wheel stability data fusion module is configured to: i) generate a first output based on a first combination of the slope flag and the wheel state flag, ii) generate a second output based on a second combination of the wheel speed phase diagram flag and the wheel state flag, and iii) generate a detection flag based on a third combination of the first output and the second output; and The torque reduction request is generated based on the detection flag.

9. The traction control module of claim 8, wherein: The plurality of markers further include a wheel acceleration marker indicating wheel acceleration and a prediction marker indicating a rate of change of a wheel speed slope, and wherein the wheel stability data fusion module is configured to generate the torque reduction request based on a fourth combination of the detection marker, the wheel acceleration marker, and the prediction marker.

10. The traction control module of claim 9, wherein: The wheel stability data fusion module comprises: a first logical AND module configured to perform said first combination; a second logical AND module configured to perform said second combination; a first logical OR module configured to perform said third combination; and A second logical OR module is configured to perform the fourth combination.

11. A vehicle comprising the traction control module according to claim 1.

12. A method for determining wheel stability, the method comprising: outputting wheel stability data based on a plurality of wheel condition inputs; calculating a plurality of wheel stability predictors based on the wheel stability data, wherein each of the wheel stability predictors independently indicates a wheel slip condition; combining selected wheel stability predictors from the plurality of wheel stability predictors to generate the combination of wheel stability predictors; and selectively outputting a torque reduction request based on said combination of said wheel stability predictors, wherein the plurality of wheel stability predictors correspond to a plurality of markers, and the method further comprises: selectively setting the plurality of markers based on the wheel stability data, and The multiple tags include: a wheel state indicia indicating at least one of: i) wheel speed relative to longitudinal speed, and ii) a relationship between slip ratio and rate of change of torque of the wheel; a slope indicia indicating at least one of: i) a slope of tire longitudinal force with respect to slip ratio, and ii) a slope of reaction torque with respect to wheel torque, wherein the reaction torque is an estimated tire rotational force transmitted to the ground; and Wheel speed phase marker indicating the deviation between the wheel speed slope and the reference slope.

13. The method according to claim 12, further comprising: i) generating a first output based on a first combination of the slope flag and the wheel state flag, ii) generating a second output based on a second combination of the wheel speed phase diagram flag and the wheel state flag, and iii) generating a detection flag based on a third combination of the first output and the second output; as well as The torque reduction request is generated based on the detection flag.

14. The method according to claim 13, wherein: The plurality of markers further include a wheel acceleration marker indicating wheel acceleration and a prediction marker indicating a rate of change of a wheel speed slope.

15. The method according to claim 14, further comprising: The torque reduction request is generated based on a fourth combination of the detection flag, the wheel acceleration flag, and the prediction flag.

16. The method according to claim 15, further comprising: performing the first combination using a first logical AND module; performing the second combination using a second logical AND module; performing the third combination using a first logical OR module; as well as The fourth combination is performed using a second logical OR module.

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