CN100381322C - Controller for electric power steering device - Google Patents

Abstract

A controller for an electric power steering device effectively reduces torque steer caused by a brake-drive power difference between left and right wheels and also effectively reduces behavior deterioration of a vehicle. The reduction is made by controlling steering assist torque. Basic assist torque (Tab) is calculated (S20-40) based on steering torque (Ts) and a vehicle speed (V), torque steer-reducing torque (Tts) promoting steering in the direction to cancel torque steer caused by a brake-drive power difference between the left and right wheels is calculated (S50), and behavior deterioration-reducing torque (Tvs) promoting steering in the direction to reduce an over steer state or an under steer state of the vehicle is calculated (S80). When the magnitude of the torque steer-reducing torque (Tts) is less than a standard value (Ttso), a target assist torque (Ta) is calculated based on the sum of Tab, Tts, and Tvs, and when the magnitude of the torque steer-reducing torque (Tts) is equal to or greater than the standard value (Ttso), the target assist torque (Ta) is calculated based on the sum of Tab and Tts.

Description

Controller for electric power steering device

Technical field

The present invention relates to the electric type power steering device of vehicle, be specifically related to controller for electric power steering device.

Background technology

In vehicles such as automobile, as one of the controller for electric power steering device of burden of operating the rudder that alleviates the driver by the assist torque of operating the rudder, be well known that for example special controller for electric power steering device of putting down in writing in the 2001-80535 communique of opening in the past, it constitutes: the braking/driving force of presumptive left and right wheels is poor, the control electric type power steering device, produce torque steer (ト Le Network ス テ ア) and alleviate torque, to promote operating the rudder to the direction of offsetting vehicle caused torque steer of braking/driving force difference of left and right wheels when on the different so-called inter-bank road of left and right sides ground-surface friction coefficient (ま ぎ road), travelling.

According to this controller for electric power steering device, the control electric type power steering device, produce torque steer and alleviate torque, to promote operating the rudder to the direction of the caused torque steer of braking/driving force difference of offsetting left and right wheels, thereby compare with the situation of not carrying out this control, can improve the riding stability of directly advancing travelling and vehicle of vehicle.

Also have, be well known that in the past, when vehicle becomes oversteer state or understeering state, work condition state according to institute's estimated vehicle, the control electric type power steering device, produce operating mode and worsen and alleviate torque, to promote that this worsens for the operating mode that alleviates the vehicle that is caused by oversteer state or understeering state is actv. to the operating the rudder of the direction that alleviates vehicle oversteer state or understeering state.

Summary of the invention

The problem that solution is planned in invention

Generally speaking, torque steer when the torque steer in the time of can not occurring producing (1) car brakeing simultaneously alleviates torque and (2) vehicular drive alleviates the situation of torque, perhaps must produce operating mode that (3) alleviate vehicle oversteer state simultaneously and worsen and alleviate operating mode that torque and (4) alleviate vehicle understeering state and worsen and alleviate the situation of torque.

By contrast, when for example vehicle spirals on the inter-bank road, the operating mode that torque and (3) alleviate vehicle oversteer state of alleviating torque steer when occurring sometimes producing (1) car brakeing simultaneously worsens and alleviates operating mode that torque or (4) alleviate vehicle understeering state and worsen and alleviate the situation of torque, and the torque steer in the time of perhaps must producing (2) vehicular drive simultaneously alleviates operating mode that torque, (3) alleviate vehicle oversteer state and worsens and alleviate operating mode that torque and (4) alleviate vehicle understeering state and worsen and alleviate the situation of torque.

Yet as mentioned above, in the controller for electric power steering device in the past, at the control electric type power steering device, produce promotion and alleviate torque to the torque steer of operating the rudder of the direction of the caused torque steer of braking/driving force difference of offsetting left and right wheels, and producing the operating mode of the operating the rudder deterioration that promotes to the direction that alleviates vehicle oversteer state or understeering state alleviates under the situation of torque, must produce torque steer alleviates torque and operating mode and worsens when alleviating torque, should how to control electric type power steering device, this is not discussed, room for improvement is arranged in this point.

In addition, above-mentioned should the improvement a little, travel on the inter-bank road for for example vehicle, in the time of should alleviating the variation of the caused vehicle working condition of braking/driving force difference of left and right wheels, the control electric type power steering device, alleviate the situation of torque thereby produce promotion to the working conditions change of operating the rudder of the direction of the variation of the caused vehicle working condition of braking/driving force difference that alleviates left and right wheels, also identical.

Disclosure of an invention

The present invention is in view of controlling electric type power steering device, produce to promote to alleviate torque to the caused torque steer of braking/driving force difference of offsetting left and right wheels or the braking/driving force difference of the operating the rudder influence of direction of variation that alleviates the caused vehicle working condition of braking/driving force difference of left and right wheels, and produce to promote the aforesaid technical task that the operating mode of operating the rudder to the direction that alleviates vehicle oversteer state or understeering state worsens under the situation that alleviates torque to make, major subjects of the present invention is, alleviating torque and operating mode according to braking/driving force difference influence worsens and alleviates torque and rationally control electric type power steering device, thereby effectively alleviate the caused torque steer of braking/driving force difference of left and right wheels and the variation of vehicle working condition, and effectively alleviate vehicle oversteer state or understeering state.

Above-mentioned main problem is solved by controller for electric power steering device of the present invention, and according to the present invention, controller for electric power steering device has at least: the device that calculates basic assist torque according to the torque of operating the rudder; Calculate the influence of braking/driving force difference and alleviate the device of torque, above-mentioned braking/driving force difference influence alleviates torque and is used to promote to the braking/driving force difference of offsetting left and right wheels operating the rudder to the direction of the influence of wheel; Design condition worsens and alleviates the device of torque, and above-mentioned operating mode deterioration alleviates torque and is used to promote operating the rudder to the direction that alleviates vehicle oversteer state or understeering state; And, influence alleviates torque or above-mentioned operating mode and worsens and alleviate torque according to above-mentioned basic assist torque and above-mentioned braking/driving force difference, calculate the auxiliary torque calculation device of target of target assist torque, control electric type power steering device according to above-mentioned target assist torque, it is characterized in that, the size that the auxiliary torque calculation device of above-mentioned target alleviates torque in above-mentioned braking/driving force difference influence is that a reference value is when above, according to above-mentioned basic assist torque and above-mentioned braking/driving force difference influence alleviate torque and, calculate above-mentioned target assist torque.

Generally speaking, the torque steer when vehicle travels on the inter-bank road reaches the variation of the vehicle working condition that causes thus, and the deterioration that becomes oversteer state or the caused vehicle working condition of understeering state with vehicle is compared, and sharply carries out.Also have, the control that vehicle becomes the braking force that the deterioration of oversteer state or the caused vehicle working condition of understeering state can be by wheel alleviates, but, the variation that the control of braking force that will be by wheel alleviates the caused vehicle working condition of torque steer, the braking force of the wheel of the high side of friction coefficient is reduced, thereby cause the increase of vehicle braked distance.Therefore alleviate torque and operating mode and worsen and alleviate under the situation of torque must producing the influence of braking/driving force difference, if selection wherein certain, preferably select the braking/driving force difference to influence and alleviate torque.

According to above-mentioned formation, the size that the influence of braking/driving force difference alleviates torque is more than a reference value, when worrying that torque steer causes the operating mode steep variation of vehicle, that influence alleviates torque according to basic assist torque and braking/driving force difference and calculate the target assist torque, thereby make braking/driving force difference influence alleviate torque to have precedence over operating mode and worsen and alleviate torque, calculate the target assist torque, so just can prevent effectively that torque steer from causing the operating mode steep variation of vehicle.

Also have, above-mentioned main problem is solved by controller for electric power steering device of the present invention, and according to the present invention, controller for electric power steering device has at least: the device that calculates basic assist torque according to the torque of operating the rudder; Calculate the influence of braking/driving force difference and alleviate the device of torque, above-mentioned braking/driving force difference influence alleviates torque and is used to promote to the braking/driving force difference of offsetting left and right wheels operating the rudder to the direction of the influence of wheel; Design condition worsens and alleviates the device of torque, and above-mentioned operating mode deterioration alleviates torque and is used to promote operating the rudder to the direction that alleviates vehicle oversteer state or understeering state; And, influence alleviates torque and above-mentioned operating mode and worsens and alleviate torque according to above-mentioned basic assist torque and above-mentioned braking/driving force difference, calculate the auxiliary torque calculation device of target of target assist torque, control electric type power steering device according to above-mentioned target assist torque, it is characterized in that, the size that the auxiliary torque calculation device of above-mentioned target alleviates torque in above-mentioned braking/driving force difference influence is that a reference value is when above, according to above-mentioned basic assist torque, above-mentioned braking/driving force difference influence alleviates torque, above-mentioned operating mode worsens and alleviates the weighted sum of torque, calculate above-mentioned target assist torque, the weighting that wherein above-mentioned braking/driving force difference influence alleviates torque worsens the weighting that alleviates torque greater than above-mentioned operating mode.

According to above-mentioned formation, the size that the influence of braking/driving force difference alleviates torque is more than a reference value, when worrying that torque steer causes the operating mode steep variation of vehicle, alleviate torque and compare and increased basic assist torque, the influence of braking/driving force difference that the influence of braking/driving force difference alleviates the weighting of torque and alleviate torque, operating mode and worsen and alleviate the weighted sum of torque according to worsening with operating mode, calculate above-mentioned target assist torque, thereby the size that has alleviated the target assist torque becomes superfluous worry, and can prevent effectively that torque steer from causing the operating mode steep variation of vehicle.

Also have, above-mentioned main problem is solved by controller for electric power steering device of the present invention, and according to the present invention, controller for electric power steering device has at least: the device that calculates basic assist torque according to the torque of operating the rudder; Calculate the influence of braking/driving force difference and alleviate the device of torque, above-mentioned braking/driving force difference influence alleviates torque and is used to promote to the braking/driving force difference of offsetting left and right wheels operating the rudder to the direction of the influence of wheel; Design condition worsens and alleviates the device of torque, and above-mentioned operating mode deterioration alleviates torque and is used to promote operating the rudder to the direction that alleviates vehicle oversteer state or understeering state; And, influence alleviates torque and above-mentioned operating mode and worsens and alleviate the auxiliary torque calculation device of target that the target assist torque is calculated in torque according to above-mentioned basic assist torque and above-mentioned braking/driving force difference, control electric type power steering device according to above-mentioned target assist torque, it is characterized in that, the auxiliary torque calculation device of above-mentioned target according to above-mentioned basic assist torque, the influence of above-mentioned braking/driving force difference alleviate torque, above-mentioned operating mode worsen alleviate torque and, calculate above-mentioned target assist torque.

According to above-mentioned formation, according to above-mentioned basic assist torque, above-mentioned braking/driving force difference influence alleviate torque, above-mentioned operating mode worsen alleviate torque and, calculate above-mentioned target assist torque, thereby the switching of calculating of target assist torque that need not alleviate the size etc. of torque based on braking/driving force difference influence, control can be simplified, and the value steep variation of target assist torque can be prevented really and the driver's that causes thus not harmony sense.

Also have, according to the present invention, in above-mentioned each formation, can constitute, the size that the auxiliary torque calculation device of above-mentioned target alleviates torque in above-mentioned braking/driving force difference influence is during less than a reference value, according to above-mentioned basic assist torque, above-mentioned braking/driving force difference influence alleviate torque, above-mentioned operating mode worsen alleviate torque and, calculate above-mentioned target assist torque.

According to above-mentioned formation, the size that alleviates torque in braking/driving force difference influence is during less than a reference value, according to basic assist torque, braking/driving force difference influence alleviate torque, operating mode worsen alleviate torque and, calculate the target assist torque, thereby can prevent effectively that vehicle from becoming the deterioration of oversteer state or the caused vehicle working condition of understeering state, and can prevent effectively that torque steer from causing the operating mode steep variation of vehicle.

Also have, according to the present invention, can constitute in the above-described configuration, the auxiliary torque calculation device of above-mentioned target limits the size of above-mentioned target assist torque with above-mentioned upper limit a reference value when the size of above-mentioned target assist torque surpasses upper limit a reference value.

According to above-mentioned formation, when the size of target assist torque surpasses upper limit a reference value, come the size of limited target assist torque with above-mentioned upper limit a reference value, thereby the size that can prevent the target assist torque really becomes superfluous, and compare with the situation of not carrying out this protective treatment, can increase size that braking/driving force difference influence alleviates torque and the ratio of the braking/driving force difference of left and right wheels and operating mode are worsened alleviate the ratio of the size of torque, thus just can high braking/driving force difference influence alleviate effect and the operating mode deterioration alleviates effect the degree of vehicle oversteer state or understeering state.

Also have, according to the present invention, can constitute in the above-described configuration, it is that promotion alleviates torque to the torque steer of operating the rudder of the direction of the caused torque steer of braking/driving force difference of offsetting left and right wheels that above-mentioned braking/driving force difference influence alleviates torque.

Also have, according to above-mentioned formation, it is that promotion alleviates torque to the torque steer of operating the rudder of the direction of the caused torque steer of braking/driving force difference of offsetting left and right wheels that the influence of braking/driving force difference alleviates torque, thereby the influence that can alleviate torque steer, just can effectively prevent the operating mode steep variation of vehicle thus.

Also have, according to the present invention, can constitute in the above-described configuration, it is that promotion alleviates torque to the working conditions change of operating the rudder of the direction of the variation of the caused vehicle working condition of braking/driving force difference that alleviates left and right wheels that above-mentioned braking/driving force difference influence alleviates torque.

Also have, according to above-mentioned formation, it is that promotion alleviates torque to the working conditions change of operating the rudder of the direction of the variation of the caused vehicle working condition of braking/driving force difference that alleviates left and right wheels that the influence of braking/driving force difference alleviates torque, thereby the influence that can alleviate the braking/driving force difference of left and right wheels, just can make the operating mode of vehicle keep stabilized conditions thus effectively.

Also have, according to the present invention, can constitute in the above-described configuration, calculate the influence of braking/driving force difference and alleviate the device of torque, with promote to the braking force difference that alleviates left and right wheels the braking force difference of the operating the rudder influence of the direction of the influence of vehicle is alleviated torque and promote to the propulsive effort difference that alleviates left and right wheels to the propulsive effort difference of the operating the rudder influence of the direction of the influence of vehicle alleviate torque and, calculate the influence of braking/driving force difference and alleviate torque.

Also have, according to the present invention, can constitute in the above-described configuration, design condition worsens and alleviates the device of torque, when promoting the oversteer of operating the rudder to the direction that alleviates vehicle oversteer state operating mode worsen operating mode when alleviating torque and promoting the understeering of operating the rudder to the direction that alleviates vehicle understeering state worsen alleviate torque and, come design condition to worsen and alleviate torque.

Also have, according to the present invention, can constitute in the above-described configuration, design condition worsens and alleviates the device of torque, and to promote the reciprocal auxiliary torque of operating the rudder of operating the rudder to the rotation direction of vehicle, operating mode worsens and alleviates torque when calculating oversteer.

Also have, according to the present invention, can constitute in the above-described configuration, design condition worsens and alleviates the device of torque, and with the operate the rudder auxiliary torque of operating the rudder of counter-force of increase, operating mode worsens and alleviates torque when calculating understeering.

Also have, according to the present invention, can constitute in the above-described configuration, design condition worsens and alleviates the device of torque, in the degree of vehicle understeering state is more than the first reference value and second a reference value when following, to alleviate the assisted diversion torque of the counter-force of operating the rudder, operating mode worsens and alleviates torque when calculating understeering.

Also have, according to the present invention, can constitute in the above-described configuration, target is assisted the torque calculation device, when the size that alleviates torque when torque steer changes more than a reference value and between less than a reference value, and the asymptotic processing that alleviates the rate of change of target assist torque.

Also have, according to the present invention, can constitute in the above-described configuration, the auxiliary torque calculation device of target strengthens the weighting that the influence of braking/driving force difference alleviates torque with the size increase that the influence of braking/driving force difference alleviates torque.

Also have,, can constitute in the above-described configuration, calculate device that the influence of braking/driving force difference alleviates torque and calculate the influence of braking force difference according to the braking force difference of left and right wheels and condition of road surface and alleviate torque according to the present invention.

Also have,, can constitute in the above-described configuration, judge condition of road surface according to the deceleration/decel of vehicle according to the present invention.

Also have, according to the present invention, can constitute in the above-described configuration, the deceleration/decel of vehicle hour is compared when big with the deceleration/decel of vehicle, reduces the influence of braking force difference and alleviates the size of torque.

Also have,, can constitute in the above-described configuration, judge that according to the braking force difference of the left and right sides front-wheel braking force of left and right wheels is poor at least according to the present invention.

Also have,, can constitute in the above-described configuration according to the present invention, according to the braking force difference of left and right sides front-wheel and the braking force difference of comparing the left and right sides trailing wheel that has alleviated weighting with the braking force difference of left and right sides front-wheel and, judge that the braking force of left and right wheels is poor.

Also have, according to the present invention, can constitute in the above-described configuration, the device that the influence of calculating braking/driving force difference alleviates torque is carrying out under the situation of anti-skidding control a wheel at least, according to the braking force difference and the condition of road surface of left and right wheels, calculate the influence of braking force difference and alleviate torque.

Also have,, can constitute in the above-described configuration, increase and strengthen the influence of braking force difference and alleviate the size of torque with the ground-surface friction coefficient of the high side of ground-surface friction coefficient according to the present invention.

Also have,, can constitute in the above-described configuration, judge condition of road surface according to the deceleration/decel of the vehicle under the situation of a wheel being carried out anti-skidding control at least according to the present invention.

Also have, according to the present invention, can constitute in the above-described configuration, the deceleration/decel of vehicle is lower limit a reference value when following, the braking force difference is influenced alleviate torque and be controlled to be 0.

Also have, according to the present invention, can constitute in the above-described configuration, the deceleration/decel of vehicle is upper limit a reference value when above, the braking force difference is influenced alleviate torque and be controlled to be 0.

Also have,, can constitute in the above-described configuration, judge that according to the brake pressure difference of the left and right sides front-wheel braking force of left and right wheels is poor at least according to the present invention.

Also have,, can constitute in the above-described configuration according to the present invention, according to the brake pressure difference of left and right sides front-wheel and the brake pressure difference of comparing the left and right sides trailing wheel that has alleviated weighting with the brake pressure difference of left and right sides front-wheel and, judge that the braking force of left and right wheels is poor.

Description of drawings

Fig. 1 is the summary pie graph of an embodiment of expression controller for electric power steering device of the present invention.

Fig. 2 is the diagram of circuit of the main program of the assist torque control of operating the rudder among the expression embodiment 1.

Fig. 3 is the diagram of circuit that the torque steer among the expression embodiment 1 alleviates the subprogram of torque Tts calculating.

Fig. 4 is the diagram of circuit that the operating mode among the expression embodiment 1 worsens the subprogram that alleviates torque Tvs calculating.

Fig. 5 is a chart of representing the relation between torque Ts and the basic assist torque Tab ' of operating the rudder.

Fig. 6 is the chart of the relation between expression vehicle velocity V and the speed of a motor vehicle COEFFICIENT K v.

Fig. 7 is that expression brake pressure difference Δ P of left and right wheels and glancing impact torque steer alleviate the chart that torque Tbts (thick line) and glancing impact working conditions change alleviate the relation between the torque Tbvb (fine rule).

Operating mode worsened the chart that alleviates the relation between the torque Tovs when Fig. 8 was expression slew mode amount SS and oversteer.

Operating mode worsened the chart that alleviates the relation between the torque Tuvs when Fig. 9 was expression slip value DV and understeering.

Figure 10 is the diagram of circuit of the main program of the assist torque control of operating the rudder among the embodiment 2 of expression controller for electric power steering device of the present invention.

Figure 11 is the diagram of circuit of the main program of the assist torque control of operating the rudder among the embodiment 3 of expression controller for electric power steering device of the present invention.

Figure 12 is that the expression torque steer alleviates the absolute value of torque Tts and the chart of the relation between the COEFFICIENT K.

The specific embodiment

Following with reference to accompanying drawing, describe the present invention in detail by preferred embodiment.

Embodiment 1

Fig. 1 is the summary pie graph of the embodiment 1 of expression controller for electric power steering device of the present invention.

Among Fig. 1,10FL and 10FR represent the left and right sides front-wheel from drive wheel as vehicle 12 respectively, and 10RL and 10RR represent the left and right sides trailing wheel as the drive wheel of vehicle 12 respectively.Also the electric type power steering device 16 of driven rack-and-pinion is operated the rudder by tierod 18L and 18R by response driver's coming about of steering handwheel 14 of carrying out as the left and right sides front-wheel 10FL of the wheel of operating the rudder and 10FR.

In illustrated embodiment, electric type power steering device 16 is electric type power steering devices of tooth bar coaxial type, is controlled by electronic control package 20.Electric type power steering device 16 has electrical motor 22 and the rotating torques of electrical motor 22 is transformed to the mapping device 26 of for example round head bolt formula that ratch 24 comes and goes the power of the directions that move, generation drives the auxiliary power of coming about of ratch 24 with respect to support 28, thereby produces the assist torque of operating the rudder of the burden of operating the rudder that alleviates the driver.

The braking that the braking force of each wheel is controlled wheel cylinder 34FR, 34FL, 34RR, 34RL by the oil hydraulic circuit 32 of brake equipment 30 is pressed and is controlled.Though it is not shown, but, oil hydraulic circuit 32 comprises receiver, oil pump, various valve gears etc., and by the depressing operation of the brake pedal 36 that according to driver carry out control usually by driven master cylinder 38 for the braking pressure of each wheel cylinder, or controlled by electronic control package 40 as required.In addition, electronic control package 20 and electronic control package 40 carry out giving and accepting of necessary information mutually, when electronic control package 40 has worsened in the operating mode of vehicle, with electronic control package 20 combineds action, by the known braking force that will get the predetermined wheel of control in this technical field, thereby the operating mode of the operating mode stabilization of vehicle is controlled.

Steering shaft 42 is provided with the angle transducer 44 and detect the torque sensor 46 of the torque Ts that operates the rudder of operating the rudder that detects the angle θ that operates the rudder, and vehicle 12 is provided with the car speed sensor 48, the yaw rate sensor 50 that detects the yaw rate gamma of vehicle that detect vehicle velocity V, detect the front and back acceleration pick-up 52 of acceleration/accel Gx before and after the vehicle and detect the transverse acceleration sensor 54 of the transverse acceleration Gy of vehicle.In addition, the angle transducer 44 of operating the rudder, torque sensor 46, yaw rate sensor 50, transverse acceleration sensor 54 turn left moving direction for just with vehicle, detect operate the rudder angle θ, the torque Ts that operates the rudder, yaw rate gamma, transverse acceleration Gy respectively.

As shown in the figure, expression is input to electronic control package 20 by signal, the expression of the torque sensor 46 detected torque Ts that operate the rudder by the signal of car speed sensor 48 detected vehicle velocity V by signal, the expression of the angle transducer 44 detected angle θ that operate the rudder that operate the rudder, and expression is input to electronic control package 40 by signal, the expression of front and back acceleration pick-up 52 detected front and back acceleration/accel Gx by the signal of transverse acceleration sensor 54 detected transverse acceleration Gy by signal, the expression of yaw rate sensor 50 detected yaw rate gamma.In addition, expression in detail among the figure, but, electronic control package 20 and 40 has for example CPU, ROM, RAM and input/output port device, comprises the micro computer of the general formation that they is connected to each other by two-way shared bus.

Electronic control package 20 is according to diagram of circuit shown in Figure 2, according to torque Ts and the vehicle velocity V of operating the rudder, be calculated as the basic assist torque Tab of the burden of operating the rudder that alleviates the driver, calculate promotion and alleviate torque Tts to the torque steer of operating the rudder of the direction of the caused torque steer of braking/driving force difference that alleviates left and right wheels, calculate the operating mode of the operating the rudder deterioration that promotes to the direction that alleviates vehicle oversteer state or understeering state and alleviate torque Tvs, the size that torque steer alleviates torque Tts is during less than a reference value, according to basic assist torque Tab, torque steer alleviates torque Tts, operating mode worsen alleviate torque Tvs's and, calculate target assist torque Ta, the size that torque steer alleviates torque Tts is that a reference value is when above, according to basic assist torque Tab and torque steer alleviate torque Tts's and, calculate target assist torque Ta, according to target assist torque Ta, control electric type power steering device 16 is controlled the assist torque of operating the rudder thus.

Particularly in the illustrated embodiment, electronic control package 20 is bigger than a reference value at the absolute value of target assist torque Ta, it is big or small when excessive, carry out the size of target assist torque Ta is restricted to the protective treatment of a reference value, and when the size that alleviates torque Tts at torque steer changes, prevent the asymptotic processing big or small jumpy of target assist torque Ta between less than the situation of a reference value and the situation more than a reference value.

Also have, in illustrated embodiment, electronic control package 20 torque steer when promoting the glancing impact torque steer of operating the rudder to the direction of the caused torque steer of braking force difference of offsetting left and right wheels and alleviate torque Tbts and promoting the driving of operating the rudder to the direction of the caused torque steer of propulsive effort difference of offsetting left and right wheels alleviate torque Tdts's and, come calculating torque to turn to and alleviate torque Tts.

Also have, electronic control package 20 operating mode when promoting the oversteer of operating the rudder to the direction that alleviates vehicle oversteer state worsen when alleviating torque Tovs and promoting the understeering of operating the rudder to the direction that alleviates vehicle understeering state operating mode worsen alleviate torque Tuvs's and, come design condition to worsen and alleviate torque Tvs.

In addition, not shown as diagram of circuit, but, electronic control package 40 is according to the wheel velocity Vwi of each wheel, to get the brake slip amount SBi (i=fl that calculates body speed of vehicle Vb and each wheel by known in this technical field, fr, rl, rr), it is bigger than a reference value of anti-skidding control (ABS control) beginning that the brake slip amount SBi of certain wheel becomes, and the beginning condition of anti-skidding control is set up, and just this wheel is increased and decreased the anti-skidding control of the pressure in the wheel cylinder, make the brake slip quantitative change in the predetermined scope, set up up to the termination condition of anti-skidding control.

Also have, electronic control package 40 is according to the wheel velocity Vwi of each wheel, to get the acceleration amount of skidding SAfrl and the SArr that calculates body speed of vehicle Vb and left and right sides trailing wheel by known in this technical field, it is bigger than a reference value of traction control (TRC control) beginning that the acceleration amount of skidding SArl or SArr become, the words that the beginning condition of traction control is set up, just this wheel is increased and decreased the traction control of the pressure in wheel cylinder 34FL, the 34FR, make the quantitative change of quickening to skid in the predetermined scope, set up up to the termination condition of traction control.

Have again, electronic control package 40 according to vehicle travel and the vehicle state quantity that changes, the outside slip quantity of state DS of the degree of the slew mode amount SS of the degree of the rotation of calculating expression vehicle and the outside slip of expression vehicle, according to slew mode amount SS and outside slip quantity of state DS, calculating makes the target braking force of each wheel of operating mode control of operating mode stabilization of vehicle or the target rate of skidding, use the pressure in high-pressure source, with driver's brake operating irrespectively, control the braking of each wheel presses according to target braking force or the target rate of skidding, give braking force to predetermined wheel thus, make the operating mode stabilization of vehicle.

For example electronic control package 40 is when vehicle is slew mode, give braking force to rotating outside front-wheel, vehicle is rotated the yaw moment that suppresses direction, thereby suppress rotation, when vehicle is the outside slip state, give braking force to left and right sides trailing wheel, make car retardation and vehicle is rotated the yaw moment of auxiliary direction, thereby suppress outside slip.Anti-skidding control, traction control, operating mode control itself are not main points of the present invention, thereby these controls get final product by known will getting arbitrarily in the technical field separately.

Secondly, the assist torque control of operating the rudder among the embodiment 1 is described with reference to Fig. 2 to diagram of circuit shown in Figure 4.In addition, the control of the diagram of circuit shown in Figure 2 never closure of graphic ignition lock begins, and till opening to ignition lock, carries out repeatedly by each preset time.

At first, in step 10, represent to operate the rudder the reading in of signal etc. of angle θ, in step 20, according to the torque Ts that operates the rudder, calculate basic assist torque Tab ' according to cooresponding curve in the chart shown in Figure 5, the big more basic assist torque Tab ' of size of the feasible torque Ts that operates the rudder is just big more, in step 30, according to vehicle velocity V, calculate speed of a motor vehicle COEFFICIENT K v according to cooresponding curve in the chart shown in Figure 6, make the high more speed of a motor vehicle COEFFICIENT K of vehicle velocity V v just more little, in step 40, with the basic assist torque Tab that calculates with after the revisal of speed of a motor vehicle coefficient that amasss of speed of a motor vehicle COEFFICIENT K v and basic assist torque Tab '.

In step 50, come calculating torque to turn to according to diagram of circuit shown in Figure 3 and alleviate torque Tts, in step 80, come design condition to worsen according to diagram of circuit shown in Figure 4 and alleviate torque Tvs.

In step 100, carry out torque steer and whether alleviate the absolute value of torque Tts than the big judgement of a reference value Ttso (positive fixed number), when making negative evaluation, in step 110 with basic assist torque Tab, torque steer alleviate torque Tts, operating mode worsen alleviate torque Tvs's and calculate target assist torque Ta, when making affirmative determination, in step 120, alleviate torque Tts with basic assist torque Tab and torque steer and calculate target assist torque Ta.

In step 200, because the judgement in above-mentioned steps 100 is switched between negative evaluation and affirmative determination, thereby the calculating of target assist torque Ta is when having switched between step 110 and 120, for preventing the value steep variation of target assist torque Ta, carry out the asymptotic processing of target assist torque Ta as required, for example, the value of target assist torque Ta is gradually changed from switching the value of preceding value after switching by rate of change protective treatment or filtration treatment.

In step 210, whether the absolute value that carries out target assist torque Ta is than the big judgement of a reference value Tao (positive fixed number), be the whether excessive judgement of size of target assist torque Ta, just directly enter step 230 when making negative evaluation, just enter step 220 when making affirmative determination.

In step 220, the symbol of signTa as target assist torque Ta, Ta is made as TaosignTa the target assist torque, in step 230, the pairing control signal of target assist torque Ta is outputed to electrical motor 22, alleviate the assist torque control of operating the rudder of the required power of operating the rudder of driver thus.

Alleviate in the step 52 of torque Tts calculation procedure at torque steer shown in Figure 3, whether be judgement more than a reference value for example according to master cylinder pressure Pm, carry out whether carrying out the judgement of brake operating by the driver, it promptly whether is the judgement in the braking, just enter step 60 when making negative evaluation, just enter step 54 when making affirmative determination.

In step 54, for example the poor Pfl-Pfr that presses with the braking of left and right sides front-wheel calculates the brake pressure difference Δ P of left and right wheels.In addition, the brake pressure difference Δ P of left and right wheels to the weighting of the brake pressure difference of left and right sides trailing wheel be made as Kr (for example 0.5 like this than 0 big than 1 little on the occasion of), the brake pressure difference Δ P of left and right wheels also can be according to following formula 1, and their weighted sum of weighting that has alleviated the brake pressure difference of left and right sides trailing wheel with the brake pressure difference to left and right sides front-wheel is calculated.

ΔP＝Pfl-Pfr+Kr(Prl-Prr)……(1)

In step 56, carry out whether at least a wheel being carried out skidproof judgement, enter step 60 when making negative evaluation, enter step 58 when making affirmative determination.

In step 58, carry out vehicle deceleration/decel Gbx (=-Gx) whether big than lower limit a reference value Gbx1, than the little judgement of upper limit a reference value Gbx2, in step 60, the glancing impact torque steer is alleviated torque Tbts when making negative evaluation and be made as 0, enter step 62 when making affirmative determination.

In addition, lower limit a reference value Gbx1 at acceleration due to gravity during for g is-value of 0.2g degree, it is following a reference value, this a reference value is used to prevent because the braking force of the caused left and right wheels such as deviation of the relation between the detection error of pressure sensor and braking pressure and the braking force is poor, although the torque steer of the degree that vehicle should suppress and working conditions change do not produce, and unnecessarily control electric type power steering device, the generation unnecessary torque turns to and alleviates torque.Also have, upper limit a reference value Gbx2 is following a reference value, this a reference value is used to prevent that the braking force difference of left and right wheels under the situation that has produced high deceleration/decel from not becoming big, and under this situation, unnecessarily control electric type power steering device according to the braking force difference of left and right wheels, the generation unnecessary torque turns to and alleviates torque.

In step 62, according to the brake pressure difference Δ P of left and right wheels and the deceleration/decel Gbx of vehicle, according to Fig. 7 in the chart shown in the thick line cooresponding curve calculate the glancing impact torque steer and alleviate torque Tbts, make that the size of brake pressure difference Δ P of left and right wheels is big more, the size that the glancing impact torque steer alleviates torque Tbts is just big more, and the deceleration/decel Gbx of vehicle is high more, and the size that the glancing impact torque steer alleviates torque Tbts is just big more.

In step 64, whether be the judgement of drawing in (TRC) control, enter step 68 when making negative evaluation, enter to step 66 when making affirmative determination.

In step 66, to get the propulsive effort difference Δ Fdr that infers as the left and right sides trailing wheel of drive wheel by known in this technical field, and whether the absolute value of propulsive effort difference Δ Fdr that carries out left and right sides trailing wheel is than the big judgement of a reference value Δ Fdro (positive fixed number), the judgement of the situation that the torque steer when promptly whether being driving becomes excessive, when making negative evaluation in step 68 when driving torque steer alleviate torque Tdts and be made as 0, in step 70 Kdts is made as positive certain coefficient when making affirmative determination, torque steer alleviates torque Tdts when calculating driving with amassing of Kdts and Δ Fdr.

In step 72, with the glancing impact torque steer alleviate torque Tbts and when driving torque steer alleviate torque Tdts's and come calculating torque to turn to alleviate torque Tts, enter step 80 then.

Alleviate in the step 82 of torque Tvs calculation procedure in operating mode deterioration shown in Figure 4, calculate the deviation of transverse acceleration with the deviation Gy-γ V of the long-pending γ V of transverse acceleration Gy and vehicle velocity V and yaw rate gamma, be the sideslip acceleration/accel Vyd of vehicle, calculate the sideslip speed Vy of car body by integration sideslip acceleration/accel Vyd, with the sideslip speed Vy of car body the ratio Vy/Vx of speed Vx (=vehicle velocity V) before and after the car body is calculated the angle β that skids of car body again.

In step 84, respectively K1 and K2 are made as positive fixed number, linear and K1 β+K2Vyd with skid the angle β and the sideslip acceleration/accel Vyd of car body calculates rotation amount SV, and judge the rotation direction of vehicle according to the symbol of yaw rate gamma, slew mode amount SS turns left when moving with SV at vehicle, turn right when moving at vehicle and to calculate with-SV, it is 0 that result of calculation is established the slew mode amount during for negative value.In addition, rotation amount SV also can be with the linear of angle β and differential value β d thereof and calculating of skidding of car body.

In step 86, according to slew mode amount SS, operating mode worsens and alleviates torque Tovs when cooresponding curve calculates oversteer in the chart shown in Figure 8, makes that the size of slew mode amount SS is big more, and to worsen the size that alleviates torque Tovs just big more for operating mode during oversteer (OS).

In step 88, calculate the real rudder angle δ of front-wheel according to the angle θ that operates the rudder, if H is a wheelbase, if Kh is stable factor, calculate target yaw rate γ e according to following formula 2, and establishing T is time constant, and establishing s is Laplacian, calculates according to following formula 3 and infers yaw rate gamma t based on the vehicle of the vehicle velocity V and the angle θ that operates the rudder.In addition, target yaw rate γ e also may be thought of as moving yaw-rate and the transverse acceleration Gy that adds vehicle calculates.

γe＝Vδ/{(1+KhV ²)H}......(2)

γt＝γe/(1+Ts)......(3)

In step 90, calculate slip value DV according to following several 4, and judge the rotation direction of vehicle according to the symbol of yaw rate gamma, outside slip quantity of state DS turns left when moving with DV at vehicle, turn right when moving at vehicle and to calculate, when result of calculation is negative value the outside slip quantity of state is made as 0 with-DV.In addition, slip value DV also can calculate according to following several 5.

DV＝(γt-γ)……(4)

DV＝H(γt-γ)/V……(5)

In step 92, according to outside slip quantity of state DS, operating mode worsens and alleviates torque Tuvs when cooresponding curve calculates understeering in the chart shown in Figure 9, makes that the size of outside slip quantity of state DS is big more, and to worsen the size that alleviates torque Tuvs just big more for operating mode during understeering (US).

As shown in Figure 9, during understeering operating mode worsen alleviate torque Tuvs when the size of outside slip quantity of state DS be more than the first reference value DS1 and second a reference value DS2 when following, assist torque with the direction that alleviates the counter-force of operating the rudder is calculated, like this, the driver with regard to according to operate the rudder counter-force reduce recognize vehicle near the boundary of understeering state.

In step 94, the operating mode deterioration alleviated torque Tuvs's and comes the design condition deterioration to alleviate torque Tvs when the operating mode deterioration alleviated torque Tovs and understeering during with oversteer, entered step 100 then.

Like this, according to illustrated embodiment 1, in step 20～40, torque Ts and vehicle velocity V are calculated basic assist torque Tab according to operating the rudder, the size of the feasible torque Ts that operates the rudder is big more, its size is just big more, and vehicle velocity V is high more, its size is just more little, in step 50, calculating promotes to alleviate torque Tts to the torque steer of operating the rudder of the direction of the caused torque steer of braking/driving force difference of offsetting left and right wheels, in step 80, calculates the operating mode of the operating the rudder deterioration that promotes to the direction that alleviates vehicle oversteer state or understeering state and alleviates torque Tvs.

And, in step 100～120, the size that torque steer alleviates torque Tts is during less than a reference value Ttso, according to basic assist torque Tab, torque steer alleviate torque Tts, operating mode worsen alleviate torque Tvs's and calculate target assist torque Ta, the size that torque steer alleviates torque Tts is that a reference value Ttso is when above, alleviate torque Tts's and calculate target assist torque Ta according to basic assist torque Tab. and torque steer, in step 230, according to target assist torque Ta, control the assist torque of operating the rudder by control electric type power steering device 16.

Therefore, the size that torque steer alleviates torque Tts is more than a reference value Ttso, when worrying that torque steer causes the operating mode rapid deterioration of vehicle, torque steer alleviates torque Tts and has precedence over operating mode and worsen and to alleviate torque Tvs, calculate target assist torque Ta, thereby can prevent effectively that torque steer from causing the operating mode rapid deterioration of vehicle.

Particularly according to illustrated embodiment 1, the size that torque steer alleviates torque Tts is that a reference value Ttso is when above, do not consider that the operating mode deterioration alleviates torque Tvs, alleviate torque Tts's and calculate target assist torque Ta according to basic assist torque Tab and torque steer, even thereby under the size that torque steer alleviates torque Tts is situation more than a reference value Ttso, with considered that operating mode worsens the situation that alleviates torque Tvs and compares, improved torque steer and alleviated the ratio of torque Tts the braking/driving force difference of left and right wheels, it is superfluous that the size of also not too worrying target assist torque Ta becomes, thereby can be really and effectively prevent to improve torque steer and alleviate torque Tts is caused vehicle by torque steer to the ratio of the braking/driving force difference of left and right wheels operating mode rapid deterioration.

Embodiment 2

Figure 10 is the diagram of circuit of the main program of the assist torque control of operating the rudder among the embodiment 2 of expression controller for electric power steering device of the present invention.In addition, in Figure 10 to the step identical with step shown in Figure 2 pay with Fig. 2 in the identical step number of step number.

In this embodiment 2, the carrying out of step 10～110 and step 200～230 is identical with the situation of the foregoing description 1, when in step 100, making affirmative determination, just in step 130, COEFFICIENT K is made as than 0.5 big than 1 little positive fixed number, calculates target assist torque Ta according to following formula 6.

Ta＝Tab+K·Tts+(1-K)Tvs……(6)

Like this, according to illustrated embodiment 2, the size that torque steer alleviates torque Tts is a reference value Ttso when above, according to operating mode worsen alleviate torque Tvs compare the basic assist torque Tab that increased torque steer and alleviated the weighting of torque Tts. torque steer alleviates torque Tts, operating mode worsens the weighted sum that alleviates torque Tvs and calculates target assist torque Ta.

Therefore, the size that torque steer alleviates torque Tts is more than a reference value Ttso, when worrying that torque steer causes the operating mode rapid deterioration of vehicle, alleviating torque Tvs with the operating mode deterioration compares, also increased the weighting that torque steer alleviates torque Tts, calculate target assist torque Ta according to the two, thereby the size that has alleviated target assist torque Ta becomes superfluous worry, and can prevent effectively that torque steer from causing the operating mode rapid deterioration of vehicle.

In addition, in the illustrated embodiment 2, COEFFICIENT K is positive fixed number, but, for example shown in Figure 12, also can alleviate the size of torque Tts and variable setting according to torque steer, make it become big greatly with the size change that torque steer alleviates torque Tts, in this case, the worry of the operating mode rapid deterioration that size is big more, torque steer causes vehicle that torque steer alleviates torque Tts is high more, it is high more to the percentage contribution of target assist torque Ta just to make torque steer alleviate torque Tts, just can prevent effectively further that thus torque steer from causing the operating mode rapid deterioration of vehicle.

Embodiment 3

Figure 11 is the diagram of circuit of the main program of the assist torque control of operating the rudder among the embodiment 3 of expression controller for electric power steering device of the present invention.In addition, in Figure 11 to the step identical with step shown in Figure 2 pay with Fig. 2 in the identical step number of step number.

In this embodiment 3 also be, the carrying out of step 10～110 and step 200～230 is identical with the situation of the foregoing description 1 and 2, the words that step 110 is finished, just carry out step 210, like this, target assist torque Ta often with basic assist torque Tab, torque steer alleviate torque Tts, operating mode worsen alleviate torque Tvs's and calculate.

Like this, according to illustrated embodiment 3, do not switch to the size that alleviates torque Tts according to torque steer and calculate target assist torque Ta, thereby can prevent the value steep variation of target assist torque Ta really and the driver's that causes thus not harmony sense, can also omit the asymptotic processing of the step 200 in the foregoing description 1 and 2, and can alleviate the calculated load of electronic control package 20, reduce the desired performance of its component parts.

In addition, according to graphic each embodiment, in step 210 and 220, carried out protective treatment, make the size of target assist torque Ta be no more than a reference value Tao, thereby at target assist torque Ta with basic assist torque Tab, torque steer alleviates torque Tts, operating mode worsen alleviate torque Tvs and situation that calculate under, the size that also can prevent target assist torque Ta really becomes superfluous, and compare with the situation of not carrying out this protective treatment, can increase size that torque steer alleviates torque Tts to the ratio of the braking/driving force difference of left and right wheels and operating mode worsen alleviate torque Tvs size to the slew mode amount SS of vehicle or the ratio of outside slip quantity of state DS, alleviate effect and operating mode and worsen and alleviate effect thereby can improve torque steer.

Also have, according to graphic each embodiment, in step 52～62, calculate promotion and alleviate torque Tbts to the glancing impact torque steer of operating the rudder of the direction of the caused torque steer of braking force difference of offsetting left and right wheels, torque steer alleviates torque Tdts when calculate promoting the driving of operating the rudder to the direction of the caused torque steer of propulsive effort difference of offsetting left and right wheels in step 64～70, in step 72 with these torques and come calculating torque to turn to alleviate torque Tts, even thereby certain generation of the caused torque steer of propulsive effort difference of the caused torque steer of braking force difference of left and right wheels and left and right wheels, also can effectively alleviate torque steer.

Also have, according to graphic each embodiment, operating mode worsens and alleviates torque Tovs when calculate promoting the oversteer of operating the rudder to the direction that alleviates vehicle oversteer state in step 82～86, operating mode worsens and alleviates torque Tuvs when calculate promoting the understeering of operating the rudder to the direction that alleviates vehicle understeering state in step 88～92, with these torques and come design condition to worsen to alleviate torque Tvs, even thereby certain state of vehicle oversteer state and understeering state occurs, the operating mode that also can effectively alleviate vehicle worsens.

Also have, according to graphic each embodiment, operating mode worsens and alleviates torque Tuvs during understeering, when the size of outside slip quantity of state DS is more than the first reference value DS1 and second a reference value DS2 when following, assist torque with the direction that alleviates the counter-force of operating the rudder is calculated, thus can by the counter-force of operating the rudder reduce make the driver understand vehicle near the boundary of understeering state.

Also have, according to illustrated embodiment 1 and 2, in step 200, carry out the asymptotic processing of target assist torque Ta as required, thereby the calculating that can effectively prevent target assist torque Ta has been when having switched between step 110 and step 120 or 130, the value steep variation of target assist torque Ta and the driver's who causes thus not harmony sense.

Also have, according to graphic each embodiment, the glancing impact torque steer alleviates torque Tbts and calculates according to the brake pressure difference Δ P of left and right wheels and the deceleration/decel Gbx1 of vehicle, make that the size of brake pressure difference Δ P of left and right wheels is big more, the size that the glancing impact torque steer alleviates torque Tbts is just big more, and the deceleration/decel Gbx of vehicle is high more, the size that the glancing impact torque steer alleviates torque Tbts is just big more, the deceleration/decel Gbx of vehicle uprises with the ground-surface friction coefficient and uprises, thereby can increase with the ground-surface friction coefficient, the size of the caused torque steer of braking force difference of left and right wheels becomes big and strengthens the size that the glancing impact torque steer alleviates torque Tbts.

Therefore, can prevent under the little situation of deceleration/decel low at the ground-surface friction coefficient, vehicle, the size that the glancing impact torque steer alleviates torque becomes superfluous, and under the big situation of the deceleration/decel that can be created in ground-surface friction coefficient height, vehicle really the glancing impact torque steer of necessary size alleviate torque, with only calculate the situation that the glancing impact torque steer alleviates torque and compare according to the braking force difference of left and right wheels, rationally torque steer alleviates torque during control brake.

Also have, according to graphic each embodiment, it is high more by the deceleration/decel Gbx of vehicle that the glancing impact torque steer alleviates torque Tbts, the glancing impact torque steer alleviates the size of torque Tbts and calculates like that with regard to big more, the result, the ground-surface friction coefficient can be judged according to the deceleration/decel Gbx of vehicle, thereby just judged the pairing condition of road surface of ground-surface friction coefficient easily.

Also have, according to graphic each embodiment, not only under the size of the brake pressure difference Δ P of left and right wheels is situation below a reference value Δ Po, and below the deceleration/decel Gbx of vehicle is lower limit a reference value Gbx1 or upper limit a reference value Gbx2 when above, also the glancing impact torque steer is alleviated torque Tbts and be made as 0, do not produce the glancing impact torque steer and alleviate torque Tbts, although thereby turn to not high at the actual torque of glancing impact, and the detection error of pressure sensor 52i etc. cause that the size of the brake pressure difference Δ P of left and right wheels is under the above situation of a reference value Δ Po, can prevent really that unnecessarily producing the glancing impact torque steer alleviates torque Tbts.

Also have, according to graphic each embodiment, the glancing impact torque steer alleviates torque Tbts and at least a wheel is being carried out under the situation of anti-skidding control, calculate according to the brake pressure difference Δ P of left and right wheels and the deceleration/decel Gbx of vehicle, thereby compare with not considering the situation of whether carrying out anti-skidding control, torque steer alleviates torque Tbts in the time of can correctly coming control brake according to the ground-surface friction coefficient.

More than, describe the present invention in detail with regard to certain embodiments, but, the present invention is not limited to the foregoing description, within the scope of the invention, other various embodiment can be arranged, and this is tangible to those skilled in the art.

For example, in the various embodiments described above, to the braking/driving force difference that alleviates left and right wheels the braking/driving force difference of the operating the rudder influence of the direction of the influence of vehicle is alleviated torque as promoting, be calculate as the glancing impact torque steer alleviate torque Tbts and when driving torque steer alleviate torque Tdts's and torque steer alleviate torque Tts, but, braking/driving force difference influence alleviates torque and also can replace torque steer to alleviate torque Tts calculating to promote the working conditions change of operating the rudder to the direction of the variation of the caused vehicle working condition of braking/driving force difference that alleviates left and right wheels to alleviate torque Tvb.

In this case, the glancing impact working conditions change alleviates torque Tbvb and calculates according to the brake pressure difference Δ P of the left and right wheels shown in the fine rule among Fig. 7 for example and the deceleration/decel Gbx of vehicle, working conditions change alleviates torque Tdvb and calculates with the big COEFFICIENT K dvb of the COEFFICIENT K dts in ratio such as the step 70 and the amassing of propulsive effort difference Δ Fdr of left and right wheels during driving, working conditions change alleviate that torque Tvb alleviates torque Tbvb with the glancing impact working conditions change and when driving working conditions change alleviate torque Tdvb's and calculate, perhaps, during car brakeing, the glancing impact working conditions change alleviates torque Tbvb and alleviates torque Tvb with working conditions change and calculate, during vehicular drive, working conditions change alleviates torque Tdvb and alleviates torque Tvb with working conditions change and calculate during driving, also is fine.

Also have, in the various embodiments described above, with the glancing impact torque steer alleviate torque Tbts and when driving torque steer alleviate torque Tdts's and come calculating torque to turn to alleviate torque Tts, but, also can change into, during car brakeing, the glancing impact torque steer alleviates torque Tbts and alleviates torque Tts as torque steer and calculate, during vehicular drive, torque steer alleviates torque Tdts and alleviates torque Tts as torque steer and calculate during driving.

Also have, in the various embodiments described above, slew mode amount SS and outside slip quantity of state DS are calculated by electronic control package 20, but, also can change into, calculate slew mode amount SS and outside slip quantity of state DS at electronic control package 40, according to them, undertaken by the control of braking/driving force under the situation of operating mode control, slew mode amount SS and outside slip quantity of state DS are input to electronic control package 20 by electronic control package 40 by communication.

Also have, in the foregoing description 1 and 2, in step 200, carry out the asymptotic processing of target assist torque Ta as required, also have, in the various embodiments described above, in step 210 and 220, carry out protective treatment for the size that makes target assist torque Ta is no more than a reference value Tao, but, step 200 or step 210 and 220 processing also can be omitted.

Also have, in the various embodiments described above, the brake pressure difference Δ P of left and right wheels presses according to the braking of the left and right wheels that pressure sensor detected and calculates, but, also can change into, press Pi, press according to the braking of the left and right wheels of being inferred and calculate according to the braking of inferring each wheel to row to the oil of wheel cylinder.

Also have, in the various embodiments described above, deceleration/decel Gbx at vehicle is bigger than lower limit a reference value Gbx1, than the little situation of upper limit a reference value Gbx2 under, calculate the glancing impact torque steer according to the deceleration/decel Gbx of the brake pressure difference Δ P of left and right wheels and vehicle and alleviate torque Tbts, but, the deceleration/decel Gbx of vehicle whether can omit by the judgement littler than upper limit a reference value Gbx2.

Also have, in the various embodiments described above, the a reference value Δ Po of the brake pressure difference Δ P of left and right wheels and ground-surface friction coefficient thereby irrelevant with the deceleration/decel Gbx of vehicle, be certain, but, also can change into, the deceleration/decel Gbx of corresponding ground-surface friction coefficient or vehicle and variable setting, make its with the ground-surface friction coefficient uprise, the deceleration/decel Gbx of vehicle uprises and diminish.

Also have, in the various embodiments described above, target assist torque Ta alleviates torque Tts or operating mode with basic assist torque Tab and torque steer and worsens and alleviate torque Tvs's and calculate, but, also can change into, add value after other such controlling torque of the damping torque of bringing together the property raising that for example makes steering system with these torques, calculate target assist torque Ta.

Have, in the various embodiments described above, vehicle is the back-wheel drive car again, but, the vehicle that the present invention was suitable for also can be front wheel drive car and four-wheel drive vehicle, also has, as long as can control the assist torque of operating the rudder arbitrarily, electric type power steering device can be a known formation arbitrarily in this technical field.

Claims (7)

1. a controller for electric power steering device has: the device that calculates basic assist torque according to the torque of operating the rudder at least; Calculate the influence of braking/driving force difference and alleviate the device of torque, above-mentioned braking/driving force difference influence alleviates torque and is used to promote to the braking/driving force difference of offsetting left and right wheels operating the rudder to the direction of the influence of wheel; Design condition worsens and alleviates the device of torque, and described operating mode deterioration alleviates torque and is used to promote operating the rudder to the direction that alleviates vehicle oversteer state or understeering state; And, influence alleviates torque or described operating mode and worsens and alleviate torque according to described basic assist torque and described braking/driving force difference, calculate the auxiliary torque calculation device of target of target assist torque, control electric type power steering device according to described target assist torque, it is characterized in that, the size that the auxiliary torque calculation device of described target alleviates torque in described braking/driving force difference influence is that a reference value is when above, according to described basic assist torque and described braking/driving force difference influence alleviate torque and, calculate described target assist torque.

2. a controller for electric power steering device has: the device that calculates basic assist torque according to the torque of operating the rudder at least; Calculate the influence of braking/driving force difference and alleviate the device of torque, described braking/driving force difference influence alleviates torque and is used to promote to the braking/driving force difference of offsetting left and right wheels operating the rudder to the direction of the influence of wheel; Design condition worsens and alleviates the device of torque, and described operating mode deterioration alleviates torque and is used to promote operating the rudder to the direction that alleviates vehicle oversteer state or understeering state; And, influence alleviates torque and described operating mode and worsens and alleviate torque according to described basic assist torque and described braking/driving force difference, calculate the auxiliary torque calculation device of target of target assist torque, control electric type power steering device according to described target assist torque, it is characterized in that, the size that the auxiliary torque calculation device of described target alleviates torque in described braking/driving force difference influence is that a reference value is when above, according to described basic assist torque, described braking/driving force difference influence alleviates torque, described operating mode worsens and alleviates the weighted sum of torque, calculate described target assist torque, the weighting that wherein said braking/driving force difference influence alleviates torque worsens the weighting that alleviates torque greater than described operating mode.

3. a controller for electric power steering device has: the device that calculates basic assist torque according to the torque of operating the rudder at least; Calculate the influence of braking/driving force difference and alleviate the device of torque, described braking/driving force difference influence alleviates torque and is used to promote to the braking/driving force difference of offsetting left and right wheels operating the rudder to the direction of the influence of wheel; Design condition worsens and alleviates the device of torque, and described operating mode deterioration alleviates torque and is used to promote operating the rudder to the direction that alleviates vehicle oversteer state or understeering state; And, influence alleviates torque and described operating mode and worsens and alleviate the auxiliary torque calculation device of target that the target assist torque is calculated in torque according to described basic assist torque and described braking/driving force difference, control electric type power steering device according to described target assist torque, it is characterized in that, the auxiliary torque calculation device of described target according to described basic assist torque, the influence of described braking/driving force difference alleviate torque, described operating mode worsen alleviate torque and, calculate described target assist torque.

4. according to any described controller for electric power steering device in the claim 1 to 3, it is characterized in that, the size that the auxiliary torque calculation device of described target alleviates torque in described braking/driving force difference influence is during less than a reference value, according to described basic assist torque, described braking/driving force difference influence alleviate torque, described operating mode worsen alleviate torque and, calculate described target assist torque.

5. according to any described controller for electric power steering device in the claim 1 to 3, it is characterized in that, the auxiliary torque calculation device of described target limits the size of described target assist torque with described upper limit a reference value when the size of described target assist torque surpasses upper limit a reference value.

6. according to any described controller for electric power steering device in the claim 1 to 3, it is characterized in that it is that promotion alleviates torque to the torque steer of operating the rudder of the direction of the caused torque steer of braking/driving force difference of offsetting left and right wheels that described braking/driving force difference influence alleviates torque.

7. according to any described controller for electric power steering device in the claim 1 to 3, it is characterized in that it is that promotion alleviates torque to the working conditions change of operating the rudder of the direction of the variation of the caused vehicle working condition of braking/driving force difference that alleviates left and right wheels that described braking/driving force difference influence alleviates torque.

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