Patent Description:
As conventional art, PTL <NUM> discloses a control device for a vehicle. The vehicle is provided with a rotating electrical machine that is capable of functioning as a generator to generate braking torque by regenerative torque and a brake control device that electrically controls braking torque of a mechanical brake provided to wheels. The control unit performs switching control that switches between braking torque generated by the rotating electrical machine and braking torque generated by the mechanical brake while keeping target braking torque.

Specifically, after the vehicle starts decelerating based on the braking torque of the rotating electrical machine, when the speed of the vehicle lowers to a predetermined switching start speed, the control device starts the switching control. Thereafter, during a time period during which the speed of the vehicle decreases from the switching start speed to a switching end speed, while keeping the total torque obtained by summing the braking torque of the rotating electrical machine and the braking torque of the mechanical brake to the target braking torque, the control device decreases the braking torque of the rotating electrical machine and increases the braking torque of the mechanical brake. When the speed of the vehicle reaches the switching end speed, the switching from the braking torque of the rotating electrical machine to the braking torque of the mechanical brake has been completed. While the switching control is performed, that is, when the switching from the braking torque of the rotating electrical machine to the braking torque of the mechanical brake is being performed, if the braking torque of the vehicle deviates from the target braking torque, the control device corrects the braking torque of the rotating electrical machine so that the mount of deviation decreases. The control device calculates the braking torque of the vehicle based on estimated surface resistance, coasting torque, vehicle acceleration, a differential ratio, a tire diameter, and reference vehicle weight.

Document <CIT> discloses a braking device for a vehicle. The braking device includes a friction brake device, a regeneration bake device, a control portion, which controls the friction braking force and the regeneration braking force through a cooperative control, and a state judging portion, which judges whether a vehicle state is in a stopped state or a non-braking operation state where the braking operation is not performed. The control portion executes a factor change control which suppresses an increase of change inclination of the friction braking force by changing a factor relating to a friction used when the hydraulic pressure is converted into the friction braking force to an increasing side and returns the factor to a value at a non-operation of the factor change control when the vehicle state is judged to be in the stopped state or the non-braking operation state by the state judging portion.

According to the control device for a vehicle described in PTL <NUM>, for example, when the acceleration of the vehicle changes greatly while the switching control is performed, the calculated value of the braking torque of the vehicle suddenly changes. Hence, the amount of correction of the braking torque of the rotating electrical machine changes greatly. For example, when the vehicle drives over a curb while the switching control is performed, or a road surface on which the vehicle travels changes from a flat surface to a sloping surface, the acceleration of the vehicle changes greatly. As a result, the amount of correction of the braking torque of the rotating electrical machine may increase. In such a case, since control torque of the rotating electrical machine suddenly changes, the vehicle cannot be stopped smoothly. This causes the ride in the car to be uncomfortable.

The present invention has been made in light of such circumstances as stated above and aims to provide a control device for a movable body, the control device being capable of stop the movable body more smoothly.

A control device according to an aspect of the present invention is defined in claim <NUM>.

According to the above configuration, after the vehicle is stopped, the braking torque depending on the braking torque difference is output from the rotating electrical machine. That is, torque corresponding to a difference between braking torque required for keeping the stopped state of the vehicle and braking torque of the braking device is output from the rotating electrical machine. Hence, since torque corresponding to the deviation of the braking torque of the braking device is output from the rotating electrical machine, while the output torque of the rotating electrical machine is suppressed from suddenly changing, a state in which braking force of the vehicle fails is difficult to occur. Thus, the vehicle can be stopped more smoothly.

Hereinafter, an embodiment of a control device for a vehicle will be described with reference to the drawings. To facilitate understanding descriptions, the same components are denoted by the same reference sign as much as possible in the drawings to omit redundant description.

First, the schematic configuration of the vehicle to which the control device of the present embodiment is installed will be described. As illustrated in <FIG>, a vehicle <NUM> includes a front MG (Motor Generator) 11a, a rear MG 11b, a front inverter device 12a, a rear inverter device 12b, and a battery <NUM>. The vehicle <NUM> is a so-called electric vehicle that travels based on power of the MGs 11a, 11b. In the present embodiment, the vehicle <NUM> corresponds to a movable body.

The inverter devices 12a, 12b convert DC power stored in the battery <NUM> to AC power and supply the converted AC power to the MGs 11a, 11b.

The MGs 11a, 11b are rotating electrical machines operating as a motor and a generator. When operating as a motor, the MGs 11a, 11b are driven based on AC power supplied from the inverter devices 12a, 12b, respectively. In the vehicle <NUM>, driving force of the front MG 11a is transferred to a right front wheel 18a and a left front wheel 18b via a front drive train 14a and a front drive shaft 15a, whereby the front wheels 18a, 18b rotate. Similarly, driving force of the rear MG 11b is transferred to a right rear wheel 18c and a left rear wheel 18d via a rear drive train 14b and a rear drive shaft 15b, whereby the rear wheels 18c, 18d rotate. As described above, the vehicle <NUM> is a so-called four-wheel drive vehicle in which the four wheels 18a to 18d function as driving wheels.

The MGs 11a, 11b perform regenerative operation when the vehicle <NUM> is braked, thereby operating as a generator. Specifically, when the vehicle <NUM> is braked, braking torque applied to the right front wheel 18a and the left front wheel 18b is input to the front MG 11a via the front drive shaft 15a and the front drive train 14a. The front MG 11a generates power based on torque reversely input from the front wheels 18b, 18c. AC power generated by the front MG 11a is converted to DC power by the front inverter device 12a and is charged in the battery <NUM>. Similarly, AC power generated by the rear MG 11b is converted to DC power by the rear inverter device 12b and is charged in the battery <NUM>.

The four wheels 18a to 18d are provided with braking devices 16a to 16d, respectively. The braking devices 16a to 16d are components of a hydraulic braking system <NUM> illustrated in <FIG>. The hydraulic braking system <NUM> drives the braking devices 16a to 16d based on a depressing operation of a brake pedal <NUM> by the driver to apply frictional force to the wheels 18a to 18d, thereby applying braking force to the vehicle <NUM>.

Specifically, as illustrated in <FIG>, the hydraulic braking system <NUM> includes the brake pedal <NUM>, a master cylinder <NUM>, a booster <NUM>, a reservoir tank <NUM>, a hydraulic circuit <NUM>, and the braking devices 16a to 16d.

The master cylinder <NUM> causes brake oil to generate hydraulic pressure based on a depressing operation of the brake pedal <NUM> by the driver. The brake pedal <NUM> is connected with the booster <NUM>. The master cylinder <NUM> is fixed to the booster <NUM>. The booster <NUM> converts, at the master cylinder <NUM>, pressure applied to the brake pedal <NUM> by a depressing operation by the driver to brake hydraulic pressure depending on the manipulated variable of the brake pedal <NUM>. In the present embodiment, brake hydraulic pressure in the master cylinder <NUM> is also referred to as master cylinder pressure. The master cylinder <NUM> is provided with a master cylinder pump, not shown, which can adjust the master cylinder pressure by applying pressure in the master cylinder <NUM>. The top of the master cylinder <NUM> is provided with the reservoir tank <NUM>. When the depressing operation of the brake pedal <NUM> is released, the master cylinder <NUM> and the reservoir tank <NUM> are in a connected state.

The hydraulic circuit <NUM> is provided between the master cylinder <NUM> and the braking devices 16a to 16d, and adjusts and transfers hydraulic pressure of brake oil between the master cylinder <NUM> and the braking devices 16a to 16d. In the present embodiment, the hydraulic pressure of brake oil corresponds to fluid pressure.

The braking devices 16a to 16d have wheel cylinders 26a to 26d, respectively. Hydraulic pressure of brake oil is transferred from the hydraulic circuit <NUM> to the wheel cylinders 26a to 26d, whereby the wheel cylinders 26a to 26d apply braking force to the wheels 18a to 18d, respectively. As the braking devices 16a to 16d configured by the wheel cylinders 26a to 26d, various types of braking devices such as drum-type and disk-type braking devices can be used.

The vehicle <NUM> has various sensors for detecting states thereof. As illustrated in <FIG>, the vehicle <NUM> has, for example, a master cylinder pressure sensor <NUM>, a wheel pressure sensor <NUM>, wheel speed sensors 32a to 32d, MG resolvers 33a, 33b, current sensors 34a, 34b, an acceleration sensor <NUM>, an accelerator position sensor <NUM>, and a brake stroke sensor <NUM>.

The master cylinder pressure sensor <NUM> detects master cylinder pressure Pmc, which is internal pressure of the master cylinder <NUM> illustrated in <FIG>. The wheel pressure sensor <NUM> detects wheel pressure Pwc, which is internal pressure of the wheel cylinders 26a to 26d illustrated in <FIG>. The wheel speed sensors 32a to 32d are respectively provided to the four wheels 18a to 18d and respectively detect wheel speeds ωwh(a) to ωwh(d), which are the number of rotations per unit time of the wheels 18a to 18d. The MG resolvers 33a, 33b are respectively provided to the two MGs 11a, 11b and respectively detect MG rotating speeds ωfmg, ωrmg, which are the number of rotations per unit time of output shafts of the MGs 11a, 11b. The current sensors 34a, 34b are also respectively provided to the two MGs 11a, 11b and respectively detect driving currents Img(a), Img(b), which are supplied to the MGs 11a, 11b.

The acceleration sensor <NUM> is mounted to a vehicle body <NUM> illustrated in <FIG> and detects an acceleration Asen of the vehicle <NUM>. The acceleration sensor <NUM> is a so-called <NUM>-axis acceleration sensor that can detect, for example, in addition to an acceleration in each of the longitudinal direction, the horizontal direction, and the vertical direction of the vehicle body <NUM>, an acceleration in each of the pitch direction, the roll direction, and the yaw direction. The accelerator position sensor <NUM> detects a depression amount Sa of the accelerator pedal of the vehicle <NUM>. The brake stroke sensor <NUM> detects a depression amount Sb of the brake pedal <NUM> illustrated in <FIG>.

The vehicle <NUM> includes various ECUs (Electronic Control Units) for controlling a plurality of devices installed therein. As illustrated in <FIG>, the vehicle <NUM> includes, for example, a brake ECU <NUM> and a traveling control ECU <NUM>. Each of the ECUs <NUM>, <NUM> is mainly configured by a microcomputer having a CPU, a ROM, a RAM, and the like. The ECUs <NUM>, <NUM> can communicate various pieces of information to each other via an in-vehicle network <NUM> provided to the vehicle <NUM>.

The brake ECU <NUM> executes a program previously stored in the ROM thereof to control the hydraulic braking system <NUM>. For example, the brake ECU <NUM> controls the hydraulic braking system <NUM> based on a braking torque required value transmitted from the traveling control ECU <NUM>. The braking torque required value is a target value of braking torque to be applied from the braking devices 16a to 16d to the wheels 18a to 18d. The brake ECU <NUM> controls the hydraulic braking system <NUM> so that the sum of the braking torque applied from the braking devices 16a to 16d to the wheels 18a to 18d, respectively, reaches the braking torque required value.

The traveling control ECU <NUM> executes a program previously stored in the ROM thereof to integrally control travel of the vehicle <NUM>. In the present embodiment, the traveling control ECU <NUM> corresponds to a control device. The traveling control ECU <NUM> has, as functional elements implemented by executing the program, for example, an information acquisition unit <NUM>, a target torque setting unit <NUM>, an MG control unit <NUM>, and a braking indication unit <NUM>.

The information acquisition unit <NUM> detects and calculates various state quantities of the vehicle <NUM> based on output signals of the sensors installed in the vehicle <NUM>. For example, the information acquisition unit <NUM> detects the master cylinder pressure Pmc, the wheel pressure Pwc, the wheel speeds ωwh(a) to ωwh(d), the MG rotating speeds ωfmg, ωrmg, the driving currents Img(a), Img(b), the acceleration Asen of the vehicle <NUM>, the depression amount Sa of the accelerator pedal, and the depression amount Sb of the brake pedal <NUM>. In addition, the information acquisition unit <NUM> further calculates various state quantities of the vehicle <NUM> based on detection values of the sensors. For example, the information acquisition unit <NUM> determines an average value of the wheel speeds ωwh(a) to ωwh(d), and, based on the determined average wheel speed, uses an arithmetic expression or the like to calculate a vehicle speed Vc, which is a traveling speed of the vehicle <NUM> and an acceleration Awh of the vehicle <NUM>. In addition, the information acquisition unit <NUM> calculates time differential values of the respective MG rotating speeds ωfmg, ωrmg to acquire a rotational acceleration afmg of the front MG 11a and a rotational acceleration armg of the rear MG 11b. Furthermore, the information acquisition unit <NUM> determines an average value of the MG rotating speeds ωfmg, ωrmg and uses the determined average value as an MG rotating speed ωmg.

The target torque setting unit <NUM> acquires the various state quantities of the vehicle <NUM> from the information acquisition unit <NUM> and sets a torque indicated value Tmg*, which is a target value of output torque of the MGs 11a, 11b.

When, for example, detecting depression of the accelerator pedal based on the depression amount Sa of the accelerator pedal acquired from the information acquisition unit <NUM>, the target torque setting unit <NUM> calculates basic driving torque based on the depression amount Sa of the accelerator pedal using an arithmetic expression, a map, or the like. The basic driving torque is a target value of driving torque to be applied to the wheels 18a to 18d in order to accelerate the vehicle <NUM>. The basic driving torque is set to a positive value when the vehicle <NUM> is accelerated in the forward movement direction, and is set to a negative value when the vehicle <NUM> is accelerated in the rearward movement direction. The target torque setting unit <NUM> calculates a driving torque required value Tdrv, which is a target value of driving torque to be output from the MGs 11a, 11b, from the calculated basic driving torque and transmits the calculated driving torque required value Tdrv to the MG control unit <NUM> as a torque indicated value Tmg*.

In addition, when detecting depression of the accelerator pedal based on the depression amount Sb of the brake pedal <NUM> acquired from the information acquisition unit <NUM>, the target torque setting unit <NUM> calculates basic braking torque based on the depression amount Sb of the brake pedal <NUM> using an arithmetic expression, a map, or the like. The basic braking torque is a target value of braking torque to be applied to the wheels 18a to 18d in order to decelerate the vehicle <NUM>. The basic braking torque is basically set to a negative value. The target torque setting unit <NUM> calculates a regenerative torque required value Trgr, which is a target value of regenerative torque to be output from the MGs 11a, 11b, from the calculated basic braking torque, and transmits the calculated regenerative torque required value Trgr to the MG control unit <NUM> as the torque indicated value Tmg*.

The MG control unit <NUM> controls driving of the MGs 11a, 11b based on the torque indicated value Tmg* transmitted from the target torque setting section <NUM>. Hence, for example, when the torque indicated value Tmg* is set to the driving torque required value Tdrv, control is performed so that the sum of the driving torque of each of the MGs 11a, 11b reaches the driving torque required value Tdrv. As a result, driving torque depending on the depression amount Sa of the accelerator pedal is output from the MGs 11a, 11b, whereby the vehicle <NUM> accelerates in the forward movement direction or the rearward movement direction.

In contrast, when the torque indicated value Tmg* is set to the regenerative torque required value Trgr, control is performed so that the sum of the regenerative torque of each of the MGs 11a, 11b reaches the regenerative torque required value Trgr. As a result, regenerative torque depending on the depression amount Sb of the brake pedal <NUM> is output from the MGs 11a, 11b, whereby the vehicle <NUM> decelerates.

It is noted that, hereinafter, driving torque and regenerative torque of the MGs 11a, 11b are referred to collectively as output torque of the MGs 11a, 11b.

Incidentally, after the vehicle <NUM> decelerates by regenerative torque of the MGs 11a, 11b and thereafter stops, if the vehicle <NUM> can be stopped only by the regenerative torque of the MGs 11a, 11b not using the hydraulic braking system <NUM>, unusual noise can be suppressed from being generated when the vehicle <NUM> stops, and behavior of the vehicle <NUM> can be stabilized.

However, when the vehicle <NUM> stops on a sloping road having a predetermined gradient, since the vehicle <NUM> is affected by external force in the longitudinal direction due to influence of the force of gravity, braking torque is required to be continuously applied to the wheels 18a to 18d to keep the vehicle <NUM> in the stopped state against the force of gravity. If regenerative torque corresponding to the braking torque is continuously output from the MGs 11a, 11b, heat may be generated from the MGs 11a, 11b due to motor lock. In addition, there may be situations in which regenerative torque cannot be continuously output from the MGs 11a, 11b due to the regulation of the control or the like. Hence, after the vehicle <NUM> stops, it is desirable to switch from regenerative torque of the MGs 11a, 11b to braking torque of the hydraulic braking system <NUM>. It is noted that the stop of the vehicle <NUM> as referred to in the present embodiment may be stopping or parking of the vehicle <NUM>. In addition, the stopped state of the vehicle <NUM> may be a stopped state or a parked state of the vehicle <NUM>.

Hence, when the vehicle <NUM> stops on a sloping road or the like, the traveling control ECU <NUM> performs switching control that switches from the regenerative torque of the MGs 11a, 11b to the braking torque of the braking devices 16a to 16d. As illustrated in <FIG>, the traveling control ECU <NUM> further includes a switching control unit <NUM> that performs the switching control.

For example, after the vehicle <NUM> starts deceleration due to regenerative operation of the MGs 11a, 11b, the switching control unit <NUM> monitors change of the vehicle speed Vc. If detecting that the vehicle speed Vc is a predetermined switching speed Vtha or lower, the switching control unit <NUM> starts the switching control. Specifically, while gradually decreasing the absolute value of the regenerative torque required value Trgr to be transmitted to the MG control unit <NUM> as time elapses, the switching control unit <NUM> transmits braking torque required value Trb corresponding to the decreasing to the brake ECU <NUM>. Hence, after the switching control is started, the braking torque required value Trb gradually increases as time elapses. While the switching control is performed, the sum of the regenerative torque required value Trgr and the braking torque required value Trb g is kept to basic braking torque depending on the depression amount of the brake pedal <NUM>. Since such switching control is performed, the regenerative torque of the MGs 11a, 11b gradually decreases, and the braking torque applied from the hydraulic braking system <NUM> to the wheels 18a to 18d gradually increases. It is noted that, hereinafter, the regenerative torque required value Trgr is also referred to as a basic regenerative torque required value Trgr.

Meanwhile, the switching control unit <NUM> calculates a stopped time required braking torque Tstp during a time period during which the switching control is performed. The stopped time required braking torque Tstp is braking torque to be applied from the hydraulic braking system <NUM> to the wheels 18a to 18d to keep the vehicle <NUM> in the stopped state after the vehicle <NUM> stops. For example, the switching control unit <NUM> acquires, from the information acquisition unit <NUM>, a first deceleration of the vehicle <NUM> detected based on an output signal of the acceleration sensor <NUM> and a second deceleration of the vehicle <NUM> detected based on the wheel speeds ωwh(a) to ωwh(d). The first deceleration mainly includes an actual deceleration of the vehicle <NUM> in the vehicle longitudinal direction and a component of the acceleration of gravity in the vehicle travelling direction. The second deceleration is an actual deceleration of the vehicle <NUM> in the vehicle longitudinal direction. Hence, the difference value between the first deceleration and the second deceleration is the component of the acceleration of gravity in the vehicle longitudinal direction. Using this, the switching control unit <NUM> calculates a difference value between the first deceleration and the second deceleration. In addition, based on the calculated difference value, using a predetermined arithmetic expression or the like, the switching control unit <NUM> calculates deceleration force, which is a gravity component acting on the vehicle <NUM> in the vehicle longitudinal direction when the vehicle <NUM> is stopped.

The switching control unit <NUM> uses, based on the calculated deceleration force, a predetermined arithmetic expression or the like to calculate the stopped time required braking torque Tstp and transmits the calculated stopped time required braking torque Tstp to the brake ECU <NUM> as the braking torque required value Trb. When the vehicle <NUM> is stopped, the brake ECU <NUM> controls the hydraulic braking system <NUM> based on the braking torque required value Trb. Hence, since the stopped time required braking torque Tstp is applied from the braking devices 16a to 16d to the wheels 18a, 18b, even when the vehicle <NUM> is stopped on a sloping road, the stopped state can be kept.

Incidentally, in comparison to control accuracy and response accuracy of the regenerative torque of the MGs 11a, 11b, control accuracy and response accuracy of the braking torque of the hydraulic braking system <NUM> is low. This causes the braking torque actually applied from the hydraulic braking system <NUM> to the wheels 18a, 18b deviates from the braking torque required value Trb. When the vehicle <NUM> stops on an upwardly-sloping road, if the braking torque deviates so that the absolute value of the braking torque of the hydraulic braking system <NUM> decreases, since the braking torque of the hydraulic braking system <NUM> fails, the vehicle <NUM> may roll down after stopping.

Meanwhile, although a method of compensating such amount of deviation of the braking torque of the hydraulic braking system <NUM> by the regenerative torque of the MGs 11a, 11b can be considered, if regenerative torque of the MGs 11a, 11b is determined based on the acceleration of the vehicle <NUM> as in the control device described in the above PTL <NUM>, the regenerative torque of the MGs 11a, 11b may change greatly when the acceleration of the vehicle <NUM> has changed suddenly. In such a case, since a great braking force is applied to the vehicle <NUM>, the vehicle <NUM> may not be smoothly stopped.

Hence, the traveling control ECU <NUM> of the present embodiment estimates differences between the braking torque required value Trb and actual values of the braking torque applied from the hydraulic braking system <NUM> to the wheels 18a to 18d based on various state quantities detected and calculated by the information acquisition unit <NUM>. In the present embodiment, the braking torque required value Trb corresponds to an ideal value of braking torque of the braking devices 16a to 16d. Then, the traveling control ECU <NUM> corrects output torque of the MGs 11a, 11b based on the differences to suppress the braking torque actually applied to the wheels 18a to 18d from deviating from the basic braking torque. In addition, the traveling control ECU <NUM> provides an upper limit and a lower limit of a regenerative torque indicated value of the MGs 11a, 11b to avoid the absolute value of the output torque of the MGs 11a, 11b from being too excessive when the vehicle <NUM> is stopped. Hence, the vehicle <NUM> can be stopped more smoothly.

Hereinafter, the control of the MGs 11a, 11b performed by the traveling control ECU <NUM> until the vehicle <NUM> is decelerated and stopped will be described in detail.

As illustrated in <FIG>, the traveling control ECU <NUM> further includes, as functional elements implemented by executing the program, a deceleration acquisition unit <NUM>, a gradient disturbance acquisition unit <NUM>, a difference ratio calculation unit <NUM>, a first difference acquisition unit <NUM>, and a second difference acquisition unit <NUM>.

The deceleration acquisition unit <NUM> calculates a disturbance deceleration difference Diffsum, which is a difference between an ideal value Di and an actual value Da of a deceleration of the vehicle <NUM> while the vehicle <NUM> decelerates.

The actual value Da of a deceleration of the vehicle <NUM> is an actual deceleration. The deceleration acquisition unit <NUM>, for example, calculates a differential value of the vehicle speed Vc acquired by the information acquisition unit <NUM> to acquire the actual value Da of a deceleration of the vehicle <NUM>.

The ideal value Di of a deceleration of the vehicle <NUM> is a deceleration to be generated in the vehicle <NUM> based on output torque of the MGs 11a, 11b, rolling resistance of a road surface, or the like. The deceleration acquisition unit <NUM>, for example, calculates the ideal value Di of a deceleration of the vehicle <NUM> based on the following expression f1. It is noted, in the expression f1, T is torque applied to the wheels 18a to 18d, I is inertia of the vehicle body <NUM>, and R is a radius of tires of the wheels 18a to 18d. [Expression <NUM>] <MAT>.

The inertia I of the vehicle body <NUM> and the radius R of tires are previously stored in the ROM of the traveling control ECU <NUM>.

The torque T is calculated from the following expression f2 by the information acquisition unit <NUM>. It is noted, in the expression f2, Tmg* is a torque indicated value, Tbrk is hydraulic braking torque, Ifmg is inertia of the front drive shaft 15a, and afmg is a rotational acceleration of the front MG 11a acquired by the information acquisition unit <NUM>. In addition, Irmg is inertia of the rear drive shaft 15b, armg is a rotational acceleration of the rear MG 11b acquired by the information acquisition unit <NUM>, and Troad is road surface reaction force torque applied to the wheels 18a to 18d based on the rolling resistance of the road surface. [Expression <NUM>] <MAT>.

The torque indicated value Tmg* is, as described above, set by the target torque setting unit <NUM>. In addition, the information acquisition unit <NUM> calculates hydraulic braking torque Tbrk based on the following expression f3. It is noted that, in the expression f3, Pwc is wheel pressure acquired by the information acquisition unit <NUM>, and BEF is a braking factor. [Expression <NUM>] <MAT>.

The braking factor BEF indicates a ratio of the braking torque actually acting on the wheels 18a to 18d to the braking torque of the braking devices 16a to 16d. The braking factor BEF is previously determined as a design value and is stored in the ROM of the traveling control ECU <NUM>. In the present embodiment, the hydraulic braking torque Tbrk calculated based on the expression f3 corresponds to a predicted value of the braking torque applied from the braking devices 16a to 16d to the wheels 18a to 18d.

The inertia Ifmg, Irmg in the expression f2 is also previously stored in the ROM of the traveling control ECU <NUM>.

Furthermore, the information acquisition unit <NUM> calculates road surface reaction force torque Tread based on the following expression f4. It is noted that, in the following expression f4, α, β, and γ are predetermined coefficients, and Vc is a vehicle speed acquired by the information acquisition unit <NUM>. [Expression <NUM>] <MAT>.

The coefficients α, β, γ are previously stored in the ROM of the traveling control ECU <NUM>.

The information acquisition unit <NUM> uses the expression f2 based on the torque indicated value Tmg* set by the target torque setting unit <NUM>, the hydraulic braking torque Tbrk calculated by the expression f3, the inertia Ifmg, Irmg previously stored in the ROM of the traveling control ECU <NUM>, the rotational accelerations afmg, armg acquired by the information acquisition unit <NUM>, and the road surface reaction force torque Troad calculated by the expression f4 to calculate basic vehicle torque T. In addition, the deceleration acquisition unit <NUM> uses the expression f1 based on the calculated basic vehicle torque T to calculate the ideal value Di of the deceleration of the vehicle <NUM>. The ideal value Di of the deceleration of the vehicle <NUM> is a deceleration of the vehicle <NUM> generated based on the basic vehicle torque T.

Herein, the vehicle <NUM> decelerates by being affected by not only the basic vehicle torque T but also other disturbance torque. The disturbance torque includes gradient disturbance torque affecting the vehicle <NUM> due to influence of the force of gravity when the vehicle <NUM> is located on a sloping road, the amount of deviation of the braking torque applied from the braking devices 16a to 16d to the wheels 18a to 18d, and the like. The amount of deviation of the braking torque is an amount of deviation between an actual value of braking torque applied from the hydraulic braking system <NUM> to the wheels 18a to 18d and the braking torque required value Trb. Actually, the vehicle <NUM> decelerates by being affected by the basic vehicle torque T and the disturbance torque. That is, the actual value Da of a deceleration of the vehicle <NUM> calculated from a differential value of the vehicle speed Vct is a deceleration of the vehicle <NUM> generated based on the basic vehicle torque T and the disturbance torque.

Based on the definitions of the actual value Da of a deceleration of the vehicle <NUM> and the ideal value Di of a deceleration of the vehicle <NUM> described above, the disturbance deceleration difference Diffsum, which is a difference therebetween, is a disturbance deceleration of the vehicle <NUM> generated based on the amount of deviation of the gradient disturbance torque and the braking torque. Specifically, the deceleration acquisition unit <NUM> calculates the disturbance deceleration difference Diffsum based on the following f5 from the actual value Da of the deceleration of the vehicle <NUM> and the ideal value Di of the deceleration of the vehicle <NUM>. It is noted that, in the expression f4, LFP indicates a function of a lowpass filter, and τ1 and τ2 indicate time constants of lowpass filters. [Expression <NUM>] <MAT>.

The time constants τ1, τ2 are previously stored in the ROM of the traveling control ECU <NUM>.

Meanwhile, the gradient disturbance acquisition unit <NUM> uses the acceleration Asen of the vehicle <NUM> detected by the acceleration sensor <NUM> and the acceleration Awh of the vehicle <NUM> determined from the wheel speeds ωwh(a) to ωwh(d) to calculate an acceleration Aslp of the vehicle <NUM> generated based on a gradient of the road surface on which the vehicle <NUM> is located. Hereinafter, the acceleration Aslp of the vehicle <NUM> is referred to as a gradient disturbance acceleration Aslp.

Specifically, the acceleration Asen of the vehicle <NUM> detected by the acceleration sensor <NUM> includes not only an actual acceleration of the vehicle <NUM> but also a gravitational acceleration component of the vehicle <NUM>. In contrast, the acceleration Awh of the vehicle <NUM> determined from the wheel speeds ωwh(a) to ωwh(d) by the information acquisition unit <NUM> is an actual acceleration of the vehicle <NUM>. Using this, as indicated by the following expression f6, the gradient disturbance acquisition unit <NUM> subtracts the acceleration Awh from the acceleration Asen to calculate the gradient disturbance acceleration Aslp. [Expression <NUM>] <MAT>.

The difference ratio calculation unit <NUM> uses the disturbance deceleration difference Diffsum calculated by the deceleration acquisition unit <NUM> and the gradient disturbance acceleration Aslp calculated by the gradient disturbance acquisition unit <NUM> to calculate a difference ratio Rpt, which is a ratio of the amount of deviation of an actual value to the ideal value of braking torque of the braking devices 16a to 16d. Specifically, based on the following expression f7, the difference ratio calculation unit <NUM> subtracts the gradient disturbance acceleration Aslp from the disturbance deceleration difference Diffsum to calculate a braking disturbance deceleration Diffbrk. The braking disturbance deceleration Diffbrk is a deceleration of the vehicle <NUM> generated based on the amount of deviation of the braking torque applied from the braking devices 16a to 16d to the wheels 18a to 18d. [Expression <NUM>] <MAT>.

The difference ratio calculation unit <NUM> calculates braking disturbance torque Tbrk, D from the braking disturbance deceleration Diffbrk based on the following expression f8. It is noted that, in the expression f8, I indicates inertia of the vehicle body <NUM>, and R is the radius of tires of the wheels 18a to 18d. [Expression <NUM>] <MAT>.

The braking disturbance torque Tbrk, D calculated by the expression <NUM> indicates the amount of deviation of the braking torque of the braking devices 16a to 16d.

In contrast, the hydraulic braking torque Tbrk calculated using the above expression f3 indicates an ideal value of the braking torque of the braking devices 16a to 16d.

Hence, as illustrated in the following expression f9, the difference ratio calculation unit <NUM> divides the braking disturbance torque Tbrk, D calculated using the expression f8 by the hydraulic braking torque Tbrk calculated using the above expression f3 to calculate the difference ratio Rpt. It is noted that, in the expression f9, Filter indicates a function based on, for example, a lowpass filter. [Expression <NUM>] <MAT>.

The first difference acquisition unit <NUM> calculates correction torque Tcor, based on the following expression f10 from the difference ratio Rpt calculated by the difference ratio calculation unit <NUM>, the braking factor BEF stored in the ROM, and the wheel pressure Pwc acquired by the information acquisition unit <NUM>
[Expression <NUM>] <MAT>.

In the present embodiment, the correction torque Tcor corresponds to a first braking torque difference, which is a difference between an ideal value and an actual value of the braking torque of the braking devices 16a to 16d.

When the switching control is performed, that is, when the absolute value of the braking torque required value Trb is increased while the absolute value of the basic regenerative torque required value Trgr is decreased, the switching control unit <NUM> calculates the torque indicated value Tmg* based on the following expression f11. [Expression <NUM>] <MAT>.

The MG control unit <NUM> controls output torque of the MGs 11a, 11b based on the torque indicated value Tmg* calculated by the expression f11. Hence, the torque output from the MGs 11a, 11b is controlled to a value obtained by adding the correction torque Tcor to the basic regenerative torque required value Trgr. As a result, in addition to the regenerative torque corresponding to the basic regenerative torque required value Trgr, the torque corresponding the amount of deviation of the braking torque of the braking devices 16a to 16d is output from the MGs 11a, 11b. Hence, the actual braking torque applied to the wheels 18a to 18d is difficult to greatly displace from the basic braking torque. Hence, the vehicle <NUM> can be stopped more smoothly.

When the vehicle <NUM> is stopped on a sloping road, if the stopped state of the vehicle <NUM> cannot be kept only by braking torque of the braking devices 16a to 16d, the second difference acquisition unit <NUM> calculates a correction value Tslp of output torque of the MGs 11a, 11b corresponding to the braking torque deficit. Hereinafter, the correction value Tslp of output torque is referred to as a gradient correction torque Tslp. In the present embodiment, the gradient correction torque Tslp corresponds to a second braking torque difference, which is a difference between braking torque required for keeping the stopped state of the vehicle <NUM> when the vehicle <NUM> is stopped and braking torque of the braking devices 16a to 16d.

Specifically, the second difference acquisition unit <NUM> calculates the gradient correction torque Tslp based on the following expression f12. It is noted that, in the expression f12, K is a feedback coefficient, ωmg is an MG rotating speed acquired by the information acquisition unit <NUM>, and T<NUM> is an initial value of the gradient correction torque. [Expression <NUM>] <MAT>.

The feedback coefficient K is previously stored in the ROM of the traveling control ECU <NUM>. The second difference acquisition unit <NUM> uses the integral term of the expression f12 as a time integral value based on elapsed time from the start of the switching control to the present time.

In addition, the second difference acquisition unit <NUM> calculates an initial value T<NUM> of the gradient correction torque based on the following expression f13. It is noted, in the expression f13, M is weight of the vehicle <NUM>, Aslp is an acceleration of the vehicle <NUM> generated based on a gradient of the road surface on which the vehicle <NUM> is located, R is a radius of tires. DEF is a gear ratio of the tires from the MGs 11a, 11b to the wheels 18c, 18d. [Expression <NUM>] <MAT>.

The weight M, the radius R of the tires, and the gear ratio DEF of the vehicle <NUM> are previously stored in the ROM of the traveling control ECU <NUM>. As the acceleration Aslp of the vehicle <NUM>, a calculated value of the above expression f6 is used.

When the vehicle <NUM> is stopped, the switching control unit <NUM> sets the gradient correction torque Tslp to the torque indicated value Tmg* as illustrated in the following expression f14. [Expression <NUM>] <MAT>.

In this regard, the switching control unit <NUM> sets the larger one of the absolute value |Trgr| of the basic regenerative torque required value and the absolute value |Tcor| of the correct torque to an upper limit of the torque indicated value Tmg*. In addition, the switching control unit <NUM> sets the smaller one of -|Trgr| and -|Tcor| to a lower value of the torque indicated value Tmg*.

The MG control unit <NUM> controls output torque of the MGs 11a, 11b based on the torque indicated value Tmg*. Hence, the torque output from the MGs 11a, 11b is controlled to the gradient correction torque Tslp. As a result, when the stopped state of the vehicle <NUM> cannot be kept only by braking torque of the braking devices 16a to 16d, since the torque corresponding to the braking torque deficit is output from the MGs 11a, 11b, the vehicle <NUM> can be kept in the stopped state.

Next, a procedure of a specific process performed by the elements of the traveling control ECU <NUM> described above will be described with reference to <FIG>.

The traveling control ECU <NUM> repeatedly performs the process illustrated in <FIG> at predetermined periods. As illustrated in <FIG>, first, in the traveling control ECU 50t, as processing of step S10, the information acquisition unit <NUM> determines whether a Ready signal of the vehicle <NUM> is an on state. The vehicle <NUM> is provided with a Ready switch operated by the driver when the vehicle <NUM> is started.

The Ready signal is an output signal of the Ready switch. When the driver turns on the Ready switch, the Ready signal becomes an on state. Hence, the processing of step S10 corresponds to processing determining whether the vehicle <NUM> has started.

If making an affirmative determination in the processing of step S10, that is, if the Ready switch is in an on state, as processing of step S11, the information acquisition unit <NUM> determines whether the hydraulic braking torque Tbrk is a predetermined torque threshold value Tth or larger. Specifically, the information acquisition unit <NUM> calculates the hydraulic braking torque Tbrk based on the above expression f3 from the wheel pressure Pwc detected by the wheel pressure sensor <NUM> and the braking factor BEF previously stored in the ROM. The torque threshold value Tth is previously determined by experiment or the like so as to be able to determine whether the brake pedal <NUM> has been depressed and is stored in the ROM of the traveling control ECU <NUM>.

If making an affirmative determination in the processing of step S11, that is, if the hydraulic braking torque Tbrk is the torque threshold value Tth or larger, the information acquisition unit <NUM> determines that the brake pedal <NUM> has been depressed. In this case, the traveling control ECU <NUM> performs processing of calculating the difference ratio Rpt as processing of step S12. The specific procedure of the deviation ratio calculation process is illustrated in <FIG>.

As illustrated in <FIG>, in the deviation ratio calculation process, first, as processing of step S20, the deceleration acquisition unit <NUM> calculates the disturbance deceleration difference Diffsum. Specifically, the deceleration acquisition unit <NUM> calculates the disturbance deceleration difference Diffsum based on the above expression f5 from the actual value Da of the deceleration of the vehicle <NUM> calculated from the differential value of the vehicle speed Vc and the ideal value Di of the deceleration of the vehicle <NUM> calculated by the above expressions f1 to f4.

As processing of step <NUM> following step S20, the gradient disturbance acquisition unit <NUM> calculates the gradient disturbance acceleration Aslp based on the above expression f6 from the acceleration Asen of the vehicle <NUM> detected by the acceleration sensor <NUM> and the acceleration Awh of the vehicle <NUM> determined from the wheel speeds ωwh(a) to ωwh(d).

As processing of step S22 following step S21, the difference ratio calculation unit <NUM> calculates the braking disturbance deceleration Diffbrk based on the above expression f7 from the disturbance deceleration difference Diffsum and the gradient disturbance acceleration Aslp respectively obtained by the processing of steps S20 and S21.

As processing of step S23 following step S22, the difference ratio calculation unit <NUM> calculates the difference ratio Rpt. Specifically, the difference ratio calculation unit <NUM> calculates the braking disturbance torque Tbrk, D based on the above expression f8 from the braking disturbance deceleration Diffbrk obtained by the processing of step S22. In addition, the difference ratio calculation unit <NUM> uses the above expression f3 to calculate the hydraulic braking torque Tbrk. Then, the difference ratio calculation unit <NUM> calculates the difference ratio Rpt based on the above expression f9 from the braking disturbance torque Tbrk, D and the hydraulic braking torque Tbrk.

Using the difference ratio Rpt determined as descried above can calculate the correction torque Tcor based on the above expression f10. In order to increase accuracy in calculating the correction torque Tcor, the traveling control ECU <NUM> of the present embodiment determines an average value of the difference ratio Rpt during a time period during which the brake pedal <NUM> is depressed and calculates the correction torque Tcor based on the determined average value of the difference ratio Rpt.

Specifically, as processing of step S24 following step S23, the difference ratio calculation unit <NUM> calculates a difference ratio integrated value SumR, n and a time integrated value SumT, n. The difference ratio calculation unit <NUM> calculates the difference ratio integrated value SumR, n based on the following expression f15. It is noted that, in the expression f15, SumR, n-<NUM> is a previous value of the difference ratio integrated value SumR, n and ΔT is predetermined minute time. [Expression <NUM>] <MAT>.

In addition, the difference ratio calculation unit <NUM> calculates the time integrated value SumT, n based on the following expression f16. It is noted that, in the expression f16, SumT, n-<NUM> is a previous value of the time integrated value SumT, n. [Expression <NUM>] <MAT>.

As processing of step S25 following step S24, the information acquisition unit <NUM> determines whether the hydraulic braking torque Tbrk is the predetermined torque threshold value Tth or larger. Processing of step S26 is similar to the processing of step S11 in <FIG>. If making an affirmative determination in the processing of step S26, that is, if determining that the brake pedal <NUM> has been depressed, the information acquisition unit <NUM> returns to the processing of step S20. Hence, during the time period during which the brake pedal <NUM> is depressed, the processing of steps S20 to S25 is repeatedly performed. Thus, the difference ratio integrated value SumR, n and the time integrated value SumT, n during the time period during which the brake pedal <NUM> is depressed can be determined.

Thereafter, if a negative determination is made in the processing of step S25, that is, when the depression of the brake pedal <NUM> is released, as the processing of step S26, the difference ratio calculation unit <NUM> calculates an average value Ave(Rpt)n of the deviation ratio based on the following expression f17. [Expression <NUM>] <MAT>.

Although the average value Ave(Rpt)n of the deviation ratio can be calculated by the above processing, for example, when the depression time of the brake pedal <NUM> is extremely short, the calculated value may include a large error. If the average value Ave(Rpt)n of the deviation ratio includes a large error, when the correction torque Tcor is calculated from the calculated value based on the above expression f10, the correction torque Tcor may be set to an incorrect value. Hence, for example, if the correction torque Tcor changes greatly, output torque of the MGs 11a, 11b changes greatly, which is undesirable.

Hence, if a difference between the current average value Ave(Rpt)n of the deviation ratio calculated when the current depression operation of the brake pedal <NUM> is performed and the previous average value Ave(Rpt)n-<NUM> of the deviation ratio calculated when the previous depression operation of the brake pedal <NUM> is performed is a predetermined value N or larger, the difference ratio calculation unit <NUM> limits the amount of change of the average value Ave(Rpt)n of the deviation ratio to the predetermined value N.

Specifically, as processing of step S27 following step S26, the difference ratio calculation unit <NUM> sets the average value Ave(Rpt)n of the deviation ratio stored in the RAM to the previous average value Ave(Rpt)n-<NUM>.

As processing of step S28 following step S27, the difference ratio calculation unit <NUM> calculates a difference value DiffR based on the following expression f18. [Expression <NUM>] <MAT>.

As processing of step S29 following step S28, the difference ratio calculation unit <NUM> determines whether the absolute value |DiffR| of the difference value is the predetermined value N or larger. If an affirmative determination is made in the processing of step S29, that is, if the absolute value |DiffR| of the difference value is the predetermined value N or larger, the difference ratio calculation unit <NUM> performs processing of step S30. Specifically, the difference ratio calculation unit <NUM> resets the current average value Ave(Rpt)n of the deviation ratio based on the following expression f19. It is noted that, in the following expression f19, sign is a signum function. [Expression <NUM>] <MAT>.

Hence, if the absolute value |DiffR| of the difference value is the predetermined value N or larger, the current average value Ave(Rpt)n of the deviation ratio is limited to a value obtained by adding or subtracting the predetermined value N to or from the previous average value Ave(Rpt)n-<NUM>.

As processing of step S31 following step S30, after storing the current average value Ave(Rpt)n of the deviation ratio in the ROM, the difference ratio calculation unit <NUM> terminates the process illustrated in <FIG>.

In contrast, if a negative determination is made in the processing of step S29, that is, if the absolute value |DiffR| of the difference value is smaller than the predetermined value N, after storing the current average value Ave(Rpt)n of the deviation ratio in the RAM without change as the processing of step S31, the difference ratio calculation unit <NUM> terminates the process illustrated in <FIG>.

Since the processes illustrated in <FIG> and <FIG> are performed, every time a depression operation of the brake pedal <NUM> of the vehicle <NUM> is performed, the average value Ave(Rpt)n of the deviation ratio is updated, and the value is stored in the RAM.

While the switching control is performed, the traveling control ECU <NUM> corrects the basic regenerative torque required value Trgr using the average value Ave(Rpt)n of the deviation ratio. Next, a specific procedure of a correction process for the basic regenerative torque required value Trgr performed by the traveling control ECU <NUM> will be described with reference to <FIG>. It is noted that the traveling control ECU <NUM> repeatedly performs the process illustrated in <FIG> at predetermined calculation periods.

As illustrated in <FIG>, in the traveling control ECU <NUM>, first, as processing of step S40, the information acquisition unit <NUM> determines whether the Ready signal of the vehicle <NUM> is an on state. In addition, if making an affirmative determination in the processing of step S40, the information acquisition unit <NUM> determines, as processing of step S41, whether the hydraulic braking torque Tbrk is the predetermined torque threshold value Tth or larger. Since the processing of steps S40 and S41 is the same as the processing of steps S10 and S11 illustrated in <FIG>, detailed descriptions of which are omitted.

If making an affirmative determination in the processing of step S41, that is, if the brake pedal <NUM> has been depressed, as processing of step S42, the information acquisition unit <NUM> determines whether the vehicle <NUM> has been stopped.

Specifically, in the processing of step S42, for example, the information acquisition unit <NUM> determines whether the following expression f20 is satisfied. It is noted that, in the following expression f20, Vca is a vehicle speed that can be calculated using an arithmetic expression or the like from the average value of the wheel speeds ωwh(a) to ωwh(d), and Vcb is a vehicle speed that can be calculated using an arithmetic expression or the like from the MG rotating speeds ωfmg, ωrmg. In addition, Vthb is a threshold value that is preset so as to be able to determine whether the vehicle has been stopped and is stored in the ROM of the traveling control ECU <NUM>. Max is a function for selecting the higher one of the vehicle speeds Vca and Vcb. The speed threshold value Vthb is set to, for example, <NUM>/h. [Expression <NUM>] <MAT>.

After the brake pedal <NUM> is depressed, until the vehicle <NUM> stops, the information acquisition unit <NUM> makes a negative determination in the processing of step S42. In this case, as processing of step S45, the first difference acquisition unit <NUM> calculates the correction torque Tcor using the above expression f10. In this case, the first difference acquisition unit <NUM> reads the average value Ave(Rpt)n of the deviation ratio stored in the RAM and uses the average value Ave(Rpt)n of the deviation ratio as the difference ratio Rpt in the expression f10.

As the processing of step S46 following step S45, the switching control unit <NUM> sets the torque indicated value Tmg* based on the above expression f11 while the switching control is performed. Next, as processing of step S47, the MG control unit <NUM> controls output torque of the MGs 11a, 11b based on the torque indicated value Tmg*. Hence, the torque output from the MGs 11a, 11b is controlled to a value obtained by adding the correction torque Tcor to the basic regenerative torque required value Trgr.

Thereafter, when the vehicle <NUM> stops, the information acquisition unit <NUM> makes an affirmative determination in the processing of step S42. In this case, as processing of step S43, the second difference acquisition unit <NUM> uses the above expression f12 to calculate the gradient correction torque Tslp. In addition, as processing of step S44 following step S43, the switching control unit <NUM> sets the torque indicated value Tmg* based on the above expression f14. In this case, the switching control unit <NUM> sets the larger one of the absolute value |Trgr| of the basic regenerative torque required value and the absolute value |Tcor| of the correct torque to an upper limit of the torque indicated value Tmg*. In addition, the switching control unit <NUM> sets the smaller one of -|Trgr| and -|Tcor| to a lower limit of the torque indicated value Tmg*. Next, as processing of step S47, the MG control unit <NUM> controls output torque of the MGs 11a, 11b based on the torque indicated value Tmg*. Hence, the torque output from the MGs 11a, 11b is basically controlled to the gradient correction torque Tslp.

Next, referring to <FIG>, an operation example of the vehicle <NUM> of the present embodiment will be described.

As illustrated in <FIG>, if the brake pedal <NUM> is depressed at time t10, as illustrated in <FIG>, the target torque setting unit <NUM> sets the basic braking torque to a value T10 depending on the depression amount Sb of the brake pedal <NUM>. In addition, as illustrated in <FIG>, the target torque setting unit <NUM> sets the basic regenerative torque required value Trgr to predetermined regenerative torque T20 depending on the basic braking torque T10 and transmits the basic regenerative torque required value Trgr to the MG control unit <NUM> as the torque indicated value Tmg*. It is noted that the predetermined regenerative torque T20 is a negative value. The MG control unit <NUM> controls the MGs 11a, 11b based on the torque indicated value Tmg*. Hence, as illustrated in <FIG>, the sum of output torque of the MGs 11a, 11b is controlled to the predetermined regenerative torque T20. As a result, as illustrated in <FIG>, the vehicle speed Vc gradually decreases.

Thereafter, when the vehicle speed Vc decreases to the switching speed Vtha at time t11, the switching control unit <NUM> starts the switching control. Hence, after time t11, the switching control unit <NUM> gradually decreases the absolute value |Trgr| of the basic regenerative torque required value from the absolute value |T20| of the predetermined regenerative torque as illustrated in <FIG>, and gradually increases the absolute value |Trb| of the braking torque required value as illustrated in <FIG>. As a result, the absolute value of the output torque of the MGs 11a, 11b gradually decreases from the absolute value |T20| of the predetermined regenerative torque as illustrated in <FIG>, and the absolute value of the braking torque of the braking devices 16a to 16d gradually increases as illustrated in <FIG>.

At this time, the torque indicated value Tmg* of the MGs 11a, 11b is set to a value obtained by adding the correction torque Tcor to the basic regenerative torque required value Trgr based on the above expression f11. For example, the correction torque Tcor is set as indicated by an alternate long and two short dashes line in <FIG>. Hence, the MGs 11a, 11b output, in addition to the regenerative torque corresponding to the regenerative torque required value Trgr, the torque corresponding the amount of deviation of the braking torque of the braking devices 16a to 16d. Hence, the actual braking torque applied to the wheels 18a to 18d is difficult to greatly displace from the basic braking torque T10. Hence, the vehicle <NUM> can be stopped more smoothly.

Thereafter, as illustrated in <FIG>, when the vehicle speed Vc decreases to <NUM>/h at time t12, that is, when the vehicle stops, while the basic regenerative torque required value Trgr is set to <NUM> at following time t13 as illustrated in <FIG>, the braking torque required value Trb is set to the stopped time required braking torque Tstp as illustrated in <FIG>. Hence, the stopped time required braking torque Tstp is applied from the braking devices 16a to 16d to the wheels 18a to 18d. If the vehicle <NUM> cannot be kept in the stopped state only by the stopped time required braking torque Tstp output from the braking devices 16a to 16d, the gradient correction torque Tslp is output from the MGs 11a, 11b as indicated by an alternate long and two short dashes line in <FIG>. The gradient correction torque Tslp can keep the stopped state of the vehicle <NUM> more reliably.

According to the traveling control ECU <NUM> of the present embodiment described above, functions and effects described in the following (<NUM>) to (<NUM>) can be obtained.

Claim 1:
A control device (<NUM>) for a movable body (<NUM>), the control device (<NUM>) being able to be installed in the movable body (<NUM>) that has a braking device (16a to 16d), the braking device (16a to 16d) being a part of a hydraulic braking system (<NUM>), capable of applying braking torque to a wheel (18a to 18d) and a rotating electrical machine (11a, 11b) capable of applying braking torque to the wheel (18a to 18d) by regenerative operation, the control device (<NUM>) comprising:
a switching control unit (<NUM>) that is configured to perform switching control that increases braking torque of the braking device (16a to 16d) while decreasing braking torque of the rotating electrical machine (11a, 11b), when the movable body (<NUM>) is decelerated; and
an information acquisition unit (<NUM>) that is configured to acquire information on a state of the movable body (<NUM>);
characterized by
a difference acquisition unit (<NUM>) that is configured to acquire a braking torque difference indicating a difference between braking torque required for keeping a stopped state of the vehicle and braking torque of the braking device (16a to 16d), when the movable body (<NUM>) is stopped, wherein
after the information acquisition unit (<NUM>) detects the stopped state of the movable body (<NUM>), the switching control unit (<NUM>) is configured to correct output torque of the rotating electrical machine (11a, 11b) based on the braking torque difference.