JPH03227731A - Constant speed running control device - Google Patents

Abstract

PURPOSE:To enhance the gradability of a vehicle by issuing a shift down direction if the integrated value of deviation exceeds a specified value, and releasing the shift-down direction if deviation or the integrated value is less than the specified value when deviation between a target speed and running speed is positive. CONSTITUTION:In a vehicle which runs at a constant speed with the opening of an engine throttle valve adjusted via a negative pressure actuator 20 by controlling the respective solenoids SL1 and SL2 of a negative pressure control valve and a negative pressure releasing valve by a CPU, a speed detecting circuit 30 detecting vehicle speed is provided so that the output is inputted to the CPU. Vehicle speed when a set switch SSW is turned on is made to be a target speed, deviation between the target speed and running speed is then obtained so that control signals are concurrently outputted in response to the integrated value of deviation. And when deviation is positive, a shift down direction is issued if the integrated value exceeds specified one, and the shift-down direction is released if deviation or the integrated value is less than the specified value.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention compares the running speed of a vehicle with a target speed, and opens a throttle valve in order to make the running speed equal to the target speed. /Related to a constant speed cruise control device that drives closed.

(Prior Art) A constant speed cruise control device compares a traveling speed with a target speed, opens a throttle valve when the former is low, and closes the throttle valve when the former is high.

The throttle valve is opened and closed by a negative pressure actuator that expands and contracts a diaphragm using, for example, negative pressure in an intake manifold. By communicating the internal space of the diaphragm with the intake manifold, the diaphragm retracts and the throttle valve is driven to open, and by communicating with the atmosphere, the diaphragm expands and the throttle valve is driven to close (for example, JP-A-62-68138@ Public bulletin).

The throttle valve opening alternately switches the space inside the diaphragm to the atmosphere such as the intake manifold.

It is determined by the time ratio (duty) of communication between the intake manifold and the atmosphere. This duty (throttle valve opening) is determined as follows.

DV=DS+GVX IM-40-CTXA)...
(1) DV: Output duty, DS: Initial set duty +
RM: Memory vehicle speed (target vehicle speed) + Ro: Current vehicle speed (traveling vehicle speed), A: 11t acceleration, GV: Integral gain, CT:
Compensation time In the above formula, the initial set duty DS is:

This is the duty that provides the throttle opening necessary for driving at the memorized vehicle speed under standard driving conditions (flat road), and is determined for each memorized vehicle speed. In addition, GVX (RM-Ro −
The term CT X A ) is a term for converging the current vehicle speed R, to the stored vehicle speed RH when a disturbance occurs. By the way, 1 For example, DS=40% (RM==801n/h), G
V=6. Q%/(km/h), CT = 1.4s
While driving on a flat road with an EC, the vehicle enters the uphill state, and the output duty DV" DS! 40
%, the vehicle cannot climb a hill and the vehicle speed begins to decrease. Therefore, the output duty DV is GVX(!ri.-R
o-CTXA). At this time,
Current acceleration A = -0.2 km/h/5een Difference between stored vehicle speed RM and current vehicle speed RO (vehicle speed deviation) RH110 = 3
．． If 0kie/h, DV=40+6.0X(3,
0+1.4X0.2)=59.6i1%. However, the integral gain GV is a value that has been matched so that it converges to prevent hunting, surge, etc. when a disturbance occurs under standard driving conditions (flat road).

The value is not as large as necessary for the vehicle speed to converge to the stored vehicle speed RH at the time of pitching. Therefore, if the climbing condition continues, the vehicle speed gradually decreases until it reaches a level determined by the climbing slope, and then balances out (this is called a set deviation), which causes a problem.

Therefore, it has been proposed to determine the duty using an arithmetic expression obtained by adding an integral term to the above-mentioned equation (1), as in the following equation (2) (Japanese Patent Laid-Open Publication No. Sho FR2-68138G).

D V - D S + G V X (Rs Ro
CT
・ Dirty ・ (2) DI
ID! +ΔDI DI: Integral duty, ΔDI: Vehicle speed deviation RM Ro
An arbitrary value determined by the term of the integral duty DI in equation (2). When the above-mentioned set deviation occurs at the time of pitching, DI gradually increases and the output duty DV increases. Therefore, the vehicle speed R, becomes the memorized vehicle speed RM. converges to.

As mentioned above, when the vehicle speed decreases on the road, the integral value increases and the output duty is increased to increase the driving force. When using an overdrive mechanism, the N power may become insufficient and the vehicle speed may gradually decrease. For this reason, a constant speed traveling device (Japanese Unexamined Patent Publication No. 63-38038 JP-A-62-85732) has been proposed, which shifts down and resets the integral value when the vehicle speed decreases by more than a predetermined value despite the duty being 100%.

(Problem to be Solved by the Invention) However, in the above-mentioned system, since a downshift is instructed after the output duty reaches the maximum value, the vehicle speed continues to decrease until the output duty reaches the maximum value. Another problem is that the vehicle speed fluctuates relatively significantly when the automatic transmission downshifts.

SUMMARY OF THE INVENTION An object of the present invention is to quickly respond to a decrease in vehicle speed when the vehicle is on the road, prevent a large decrease in vehicle speed, and suppress the vehicle speed when an automatic transmission is downshifted.

[Structure of the invention]

(Means for Solving the Problems) A constant speed cruise control device of the present invention is coupled to a throttle valve of a vehicle. Throttle drive means (20); Vehicle speed detection means (Wa) that generates an electric signal according to the speed of the vehicle.
g, LSV)': Target speed (Rs) and traveling speed (no
), and according to the integrated value (Dr), the throttle drive means (20) is energized in a direction in which the traveling speed (Ro) matches the target speed (RM). , speed control means; deviation (Δog = target speed (ltM)
- When the traveling speed (no) is positive, the deviation (ΔD
When the integrated value (DI) of I) is greater than or equal to a predetermined value (30%), a downshift is instructed and the integrated value (DT) is increased by a predetermined amount (15%).
%) and update the deviation (Rs Ro) or integral value (DI) to the specified value [(2,0km/h or 5%)
a shift instructing unit (CPU) that cancels the downshift instruction when the shift down instruction is lower than Automatic transmission means (21 to 31) for suspending shifting to a higher gear than a lower gear is provided.

(Operation) According to this, the shift instruction means (CPU)
) = target speed (RM) - traveling speed (rlo) is positive, and when the integrated value CDI) of the deviation (ΔDI) is greater than or equal to a predetermined value (30%), a downshift is instructed and the deviation (
RM-Ro) or integral value (DI) is a predetermined value (2,0km
/h or 5%), the downshift instruction is canceled. That is, it is possible to quickly detect that the vehicle has entered the climbing state and instruct a downshift, thereby further reducing running at low torque and improving the vehicle's climbing ability.

Furthermore, the output duty is large when a downshift instruction is issued, and the vehicle may accelerate excessively if the driving force increases immediately after the downshift instruction is canceled.

In the present invention, the shift instructing unit (CPU) subtracts the integrated value (DI) by a predetermined amount (15%) when instructing to downshift. This prevents excessive acceleration of the vehicle.

(Example) FIG. 1 shows an outline of the configuration of an embodiment of the present invention.

This embodiment is applied to a vehicle equipped with an automatic transmission with a lock-up function. In this embodiment, a microcomputer CPU is used to control the device. Power for this electric circuit is supplied from the on-board battery [3T] via a switch IGS linked to the ignition switch. Power converted into a stable voltage of 5V by the voltage stabilizing circuit VRG is applied to a logic circuit such as a microcomputer CPU.

BSW is a brake switch that is linked to the operation of a brake pedal (not shown), CSW is a clutch switch that is linked to the operation of a clutch pedal (not shown), and SSW is
The set switch R8W is a set switch for commanding constant speed driving, and the resume switch R8W is a resume switch for commanding restart of constant speed driving.
This is a reed switch for detecting vehicle speed. A permanent magnet M ag connected to the speedometer cable is arranged near the reed switch LSW. LP is a stop lamp.

One end of the switch BSW is connected to the switch IGS via a fuse FS2, and the other end of the switch BSW is grounded via a stop lamp LP. switch B
Both ends of SW are connected to input ports PI and P2 of the microcomputer CPU via interface circuits TFC, respectively. In addition, switches csw, s
sw.

R8W and LSW are all grounded at one end, and the other end is connected to the input port hP3. of the microcomputer CPU via the interface circuit IFC. P4. P5
and PGI concubine. Note that the input port P6 of the microcomputer CPU is an external interrupt input terminal.

Microcomputer CPU output ports P7 and P
8 have solenoid drivers SDI and SD, respectively.
2, solenoids SLI and SL2 are connected. These solenoids SLI and SL2 operate as a control solenoid and a release solenoid for a negative pressure actuator, which will be described later, respectively.

A motor driver MD that energizes a drive motor M that drives a vacuum pump vP is connected to an output port P9 of the microcomputer CP TJ.

An automatic transmission device is connected to the capo-1-PIO of the microcomputer CPU. This automatic transmission will be explained.

The input shaft of a torque converter 21 with a direct coupling (lock-up) clutch is coupled to the rotating shaft 29 of the engine. Transmission mechanism 2
The output shaft 24 of the sixth mechanism 23 to which the input shaft of No. 3 is connected drives an axle (not shown) via a propeller shaft (not shown), a differential (not shown), etc.

Torque converter 21. The overdrive mechanism 22 and gear transmission mechanism 23 are driven by a hydraulic circuit including a shift lever, a shift valve, switching solenoid valves 2G, 27, and a lock-up solenoid valve 28. shift lever
A position sensor 25 detects the set position of the shift lever.

The signal indicating the set position of the shift lever is sent by the shift controller 3, which is mainly based on a microcomputer. given to. Also.

The open/close signal of the reed switch LSW is given to the speed detection circuit 30, and the 5 circuit 30 sends the vehicle speed signal to the controller 3.
Give to 1.

The configuration of the automatic transmission device explained above has been proposed by the applicant under Patent I.
This is similar to that already presented in Jn Publication No. 56-3935/1. However, the speed gear is changed to a lower gear in response to the downshift instruction from the microcomputer CPU (
(downshift), a slight change.

The main changes have been made to the control program. An outline of the operation of this automatic transmission and the contents of control operations in response to instructions from the microcomputer CPU will be described later with reference to FIG.

FIG. 2 shows the configuration of the negative pressure actuator 20 shown in FIG. 1.

The housing l consists of two parts Ia and Ib.

The diaphragm 2 is sandwiched between these two parts la and lb. A space surrounded by the diaphragm 2 and the housing la is a negative pressure chamber, and a space surrounded by the diaphragm 2 and the housing 1b communicates with the atmosphere. A compression coil spring 3 is inserted between the housing la and the diaphragm 2, and pushes the diaphragm 2 back to the position of the imaginary line when the pressure in the negative pressure chamber is close to atmospheric pressure.

A protrusion 4 fixed near the center of the diaphragm 2 is connected to a link of a throttle valve 5.

The housing Ia is provided with a negative pressure intake lower communicating with the intake manifold 6 and atmospheric air intakes 8 and 9.

10 is a negative pressure control valve, number C is a negative pressure release valve, and both are fixed to the housing Ia.

Negative pressure control valve! The movable piece 12 of 0 is tiltable with P as a fulcrum, and a tension coil spring I3 is connected to one end.
The other end faces the control solenoid SLI. Both ends of the movable piece I2 function as a valve body, and they take in negative pressure in response to energization and deenergization of the solenoid 5LIO.
Open 2 Popular intake 1'' 8 closed (state shown) or negative pressure intake lower closed, atmospheric intake 8 opened, etc.

The negative pressure release valve 11 also has a movable piece 14 like the IO. The tension coil spring 15 and the solenoid SL2 are set to H, but the movable piece 14 closes the air intake port 9 (in the illustrated state W>) or opens it.

In addition, an inlet of an external negative pressure source (vacuum pump VP) is communicated between the intake manifold 6 and the negative pressure intake lower communicating therewith. The vacuum pump VP is driven by a motor M, and the suction pressure ( 18 is a check valve. 16 is an accelerator pedal, and 17 is a tension coil spring.

FIG. 3 shows the microcomputer CP'U shown in FIG.
Control operation of Wtll! 8, FIGS. 4 and 5.

FIG. 6, FIG. 7, FIG. 8, FIG. 9a, and FIG. 9b.

10a[! 1. 10b and 10c, the third
The details of the subroutine or interrupt processing routine shown in the figure are shown.

See Figure 3. When the microcomputer CPU is powered on (31: S means a step or subroutine of a flowchart.

The numbers are attached to the flowchart and indicate step numbers or subroutine numbers; hereinafter the same meaning), initial settings, that is, port status settings, memory clearing, parameter initial settings, etc. are performed (S2). After completing the initial settings, the microcomputer CPU processes 83 or less processes in about 50++ se.
Repeatedly execute at c cycles.

In S3, the state of input capo-1-P1-PG is read, and then in S4. S5. In SG or S7, brake switch rlsW, clutch switch CS W
*Set switch SSW *Take resume switch R8
Check which switch of W is on or not. If the brake switch nSW is on (S4) or the clutch switch C8W is on (S5), set the register S to 0 (S8), and if the set switch SSW is on (S8), set the register S to 0 (S8).
SO), set 2 to register S, Sera 1-L (S9),
If the resume switch R5W is on (S7), 3 is set in the register S (SIO).

Then, depending on the contents of register S (Sll), "standby processing J (S12), r constant speed control processing J (S13)"
, r set processing J (S14) or "resume processing J
Branches to (S15) and returns to reading the input port (S15).
3) From then on, this operation is repeated in a loop.

Note that even if fuse FS2 is blown, switch BSW
The microcomputer CP
U determines that the switch BSW is turned on both when the input port P2 becomes a high level H and when the input port PI becomes a low level L.

The external interrupt (S16) will be explained with reference to FIG.

In this example, the external interrupt occurs every time the vehicle speed detection reed switch LSW is turned on, that is, at the fall of the signal applied to the input port P6.

When an external interrupt occurs (S16), the contents of register R4 are incremented (1).As a result, in step 2, if the contents of register R4 are less than 4, the process returns to the main routine, but if the contents of register R4 are 4 or more, If so, the microcomputer CPU reads the contents of the internal hardware counter CN.

The counter CN always counts clock pulses of a predetermined period apart from the operation of the microcomputer CPU, but is cleared every four times an external interrupt occurs. Therefore, this counter CN has a reed switch LSW for vehicle speed detection.
A value corresponding to the time when four pulses are output is counted. A permanent magnet placed near the reed switch LSW has four poles, and when it rotates once, the reed switch LSW outputs four pulses. In other words, the counter CN measures the time it takes for the speedometer cable to rotate once.

The periodic data obtained by reading the contents of the counter CN is stored in register R5, and when the contents of register R4 becomes 4 or more, the contents of register R4 are cleared (3), and the periodic data stored in register R5 is , calculates the vehicle speed, and stores the result in register R, (4).

When these processes are completed, the contents of the counter CN are cleared and restarted (5), and the process returns to the main routine.

Next, timer interrupt processing (S17) will be explained with reference to FIG. In this example, a hardware timer provided internally in the microcomputer CPU is used to generate a timer interrupt request at predetermined intervals. When the timer interrupt request occurs, timer interrupt processing (S17) shown in FIG. 5 is executed.

In timer interrupt processing (S17), register RAHRB
(11), these registers are used as independent timers.

Every time the value of register Ra exceeds the predetermined value NA (12),
Store the contents of register R1 in register R2, and store the contents of register R in register R1 (13).This process is performed every time the value of register R^ exceeds a predetermined value NA, so each register R2 and R1 are filled with the latest vehicle speed and the previously measured vehicle speed, respectively.

Furthermore, the result of subtracting the value of register R2 from the value of register R1 is stored in register R3, and the contents of register RA are set to 0.
(14). This process is performed periodically at predetermined time intervals determined by the value of NA. The contents of register R3 are used as acceleration data in duty calculations to be described later.

Note that the register R, which is incremented in the timer interrupt processing (S17), is used as a timer for measuring the on time or off time of various switches. Also, although not shown in Fig. 3, ← Rake switch BSW, clutch switch c S W
.

Set switch SSW still resume switch R8W
When starting from the off state and changing to the on state, the value of the register RB is cleared to 0. This allows the elapsed time since each switch was turned on to be determined.

Next, the "standby process J (812)" will be explained with reference to FIG. When set in this way, the negative pressure control valve lO and the negative pressure release valve 1
1 communicates the negative pressure chamber within the negative pressure actuator 20 with the atmosphere. Therefore, the negative pressure actuator 20 moves in a direction that does not open the throttle valve 5.

Next, the r set processing J (814) will be explained with reference to FIG. When the set switch SSW is turned on, first, the release solenoid SL2 is set to on (31).
This allows the negative pressure release valve l! teeth.

Isolate the negative pressure chamber of the negative pressure actuator from the atmosphere.

However, even in this state, the control solenoid SLI remains off, so the negative pressure control valve lO communicates the negative pressure chamber of the negative pressure actuator with the atmosphere.

If the set switch SSW remains on (
32), then immediately return to the main routine. Therefore, even if the vehicle is in a predetermined running state, if the driver takes his foot off the accelerator pedal 16, the vehicle speed will gradually decrease. When the set switch SSW changes from on to off (
32), the contents of the register Ro at that time, that is, the current vehicle speed, are stored in the vehicle speed memory RM (33), and 1 is set in the register S (34). When 1 is set in the register S, from the next loop process, constant speed control process (S13) shown in FIGS. 9a and 9b, which will be described later, is executed.

Next, with reference to FIG.
5) will be explained. When the resume switch RSW is turned on, the release solenoid SL2 is first set on (41). Thereby, the negative pressure release valve 11 isolates the negative pressure chamber of the negative pressure actuator from the atmosphere. Next, check for overflow of the resume timer (42). Note that the resume timer is a register RB that is cleared when the resume switch R3W is turned on for the first time. If there is no overflow, return to the main routine.

When the resume timer overflows (43), the control solenoid S L 1 is turned on (44), and the contents of the register Ro are stored in the vehicle speed memory RM (45). When the control solenoid SLl is maintained in the on state, the negative pressure control valve 10 is activated by the negative pressure actuator 2.
The negative pressure chamber 0 is connected to a negative pressure system that communicates with the intake manifold 6.

Therefore, in this state, the state of the negative pressure actuator gradually changes in the direction of opening the throttle valve 5.

Vehicle speed gradually increases. When the resume switch R8W is turned off (42), the register S is set to 1 (46), and in the next loop processing, "constant speed control processing J
Proceed to (S13).

If the resume switch R5W is turned off before the resume timer overflows, the vehicle speed previously stored in the vehicle speed memory RM is read and the vehicle starts running at a constant speed. However, if the resume timer overflows, the vehicle speed Since the contents of memory R are updated to the vehicle speed at that time, the vehicle enters constant speed driving at the current vehicle speed.

Referring to FIGS. 9a and 9b, r constant speed control process J (
S13) will be explained. In FIG. 9a, when the duty control timing (every 50'm5ec) comes (51), the output duty and the integral duty are calculated in the "constant speed control duty calculation" subroutine (52).

Here, the constant speed control duty calculation J (52) will be explained with reference to FIG. 10a, FIG. 10b, and FIG. 10C. Referring to FIG. 10a, first.

An initial set duty DS is calculated (81).

Initial set duty (DS) is a duty corresponding to the memorized vehicle speed VM required when the vehicle runs on a flat road without disturbance, and is preset. Therefore, the memorized vehicle speed VM ( The initial set duty DS is calculated from the pth set loop gain GV and the stored vehicle speed VM (register R
(value stored in register H), current vehicle speed Vo (value stored in register Ro), T-set compensation time constant CT (time constant that compensates for delay in vehicle speed change with respect to change in opening degree of throttle valve 5) , and the acceleration A at that time (corresponding to the contents stored in register R3 in timer interrupt processing J (S l 7)), Gv×(vM−
vo-CTXA)... Perform the calculation of (3) (82)
. Next, the vehicle speed deviation vM-v.

Check whether is smaller than O83), V M-
When VO is less than 0, change the number;, v, -Vo is -2
, 0bm8 or less (86).

-2.0 bm/h or less, V MV o = 2
．． Set the lower limit to 0 bm/h (87). Also.

When v s -vo is 0 or more, check whether v, -vo is 5.0 or more / h or more (84), 5.0
If bm is 8 or more, an upper limit is applied to V HV o = 5.0 bm/h (85).

The upper limit is for suppressing an excessive increase in the integral value of the positive vehicle speed deviation at the time of climbing, and suppressing the overshoot of the vehicle speed at the end of climbing, and the lower limit is for suppressing the overshoot of the vehicle speed at the end of climbing. During constant speed control, when the driver depresses the accelerator pedal and manually increases the speed during override, a negative vehicle speed deviation occurs and integration is performed when exiting the vehicle or override is completed.

This is to prevent undershoot that occurs due to the integral duty DI, which will be described later. In addition, the absolute value of the limit value (V HV (1 = 2.0 bm/h) when the vehicle speed deviation is negative (when overriding or dismounting) is expressed as the mint value (y M-
By setting the value smaller than y o =5-Ok rn/h), it is possible to prevent the integral duty from increasing more than necessary when stepping down or overriding.

The cpu then steps 88, 89, 90A and 90
At step 13, it is checked whether (1) the running has changed from the uphill road to the downhill road or the flat road, and (2) whether the running has changed from the downhill road to the uphill road or the flat road.

In the case of (1) above, the integral value DI has become a positive and quite large value due to the uphill running up to now. This is checked in step 90A.

Furthermore, since the vehicle has changed from running on an uphill road to downhill road or on a flat road, the throttle opening degree is large according to the integral value DI up to that point, so the vehicle speed deviation becomes negative continuously.

Check number 29 in step 89. In step 8, VM-vo is the vehicle speed deviation calculated 9 times, VM-Vt
is the previously calculated vehicle speed deviation.

In these checks, the vehicle speed deviation vM calculated this time
-Vo and the previously calculated vehicle speed deviation VM-Vt are both negative (check 89 is YES), and the integrated value DI (
If the duty conversion value) is +15% or more (check 90A is YES), set the 〇I increase flag to indicate that the integral value is excessively large for the current driving conditions, as described in (1) above. Do (91).

In the case of (2) above, the integral value DI is negative and its absolute value is quite large due to the downhill road travel up to now. This is checked in step 90B. Also, since the driving has changed from a downhill road to an uphill road or a flat road, the throttle opening is small according to the integral value DI up to that point.
Vehicle speed deviation becomes positive continuously. This is checked in step 88. In step 88, the vehicle speed deviation VM-VO calculated this time and the vehicle speed deviation VM-VL calculated last time are both positive (check 88 is YES), and the integrated value DI (duty conversion value) is -15% or less ( If the check of 90B is Vt;S), the ΔDI increase flag should be set, which indicates that the integral value is excessively large (large on the negative side) for the current driving conditions, based on (2) above.
1), Start the ΔDI increase timer (92), until this Δ0■ increase timer times out,
Since the addition value for 'Mt is integrally added at a large gain (0,04) in subroutine 103 described later, the above (1
) or (2), the previously large integral value rapidly decreases, the vehicle speed V quickly converges to the target vehicle speed vM, and the above (
In the case of 1) or (2), overshoot or undershoot of the traveling vehicle speed with respect to the target vehicle speed is prevented.

Please refer to figure tob. If there is an integral value ΔDI increase flag (93), the integral value ΔDI increase flag is reset (95) after a predetermined time has elapsed (94).

Check again whether there is an integral value ΔDI increase flag (9G), and if there is no flag, check whether overdrive, which will be described later, is prohibited (97).

If it is not prohibited, check whether the vehicle speed deviation VM-VO is smaller than O (98), and if the vehicle speed deviation V, -Vo is 0 or more, further check whether it is 2.0 km/h or more (99).
), if the vehicle speed deviation VM-VD is 2.0 bm/h or more, the current integral addition value ΔDI is set as ΔDI=0.04X(VM
Vo)-0,02X2. Set ff to O (100)
Therefore, the integral addition value ΔDI for the current vehicle speed deviation has the relationship l shown in FIG. 12a. Vehicle speed deviation VM-V
If O is smaller than 2.0 bm/h in step 99 or smaller than 0 in step 98, the current integral addition value ΔDI is set to 1 as shown in ■ in FIG. 12a.

Set ΔDI = 0.02X (VM-Vo) (lot).

In addition, when the vehicle speed deviation VM-V is -2.0 bm/h or less,
A limiter is applied (according to step 87).

Therefore, when the vehicle speed deviation v, -V is 2 Oks/h or more, the integral gain is set large so that the integration is performed quickly, so that the vehicle speed quickly converges to the stored vehicle speed V when the vehicle is on the pitch. When descending, when the vehicle speed deviation VM-VO becomes smaller than O, the duty becomes smaller and the throttle valve 5 is immediately fully opened. Since the power level is only about 10%, the output duty decreases and the power is fully opened immediately. Therefore, when the vehicle speed deviation VM-VO is negative, integration has almost no effect, and there is no problem even if the limiter is small.In addition, if the vehicle speed deviation VM-V is negative and the integration is not performed, it will change from pitched to flat. When the vehicle shifts &;, the integral value cannot be subtracted, resulting in overshoot, so in order to prevent this, as described above,
Integration is also performed when the vehicle speed deviation is negative.

When there is an integral value ΔDI increase flag in step 96 (within a predetermined time from the change in stepping down/up), the integral gain is increased as shown in ■ in Fig. 12b, and in step 103
Set I = 0.04X (VM VO) (first
(2 times the gain of ■ in Figure 2a), therefore.

When the load changes suddenly, such as when the road surface changes from going up to going down (or vice versa), by quickly subtracting the integral value that has been added up to that point, you can eliminate overshoot or undershoot caused by the integral value. Take fewer shots.

In step 97, when the overdrive of the transmission mechanism, which will be described later, is prohibited, in step 102, as shown in ■ in Fig. 12C): ΔDIxO, 01X (Vx Vo3 and the integral gain are reduced (the gain in 1/2 times)
In other words, when overdrive is prohibited when the vehicle is on the road, the driving force of the vehicle system increases, so if the output duty is corrected using the integral gain while driving in overdrive, the gain will be too large and cause hunting, etc. When overdrive is prohibited, the integral gain is made smaller than when running in overdrive.

In step 104, the previous integral duty DI and the integral addition value ΔDI are added together using the code material, and the one-way work area WOR is added.
Stored in K. Additionally, this value is limited to 40% (105.106).

See Figure 10e. In step 1O, the output duty oVtrl is determined by adding the initial set duty DS (81) and the value of equation (3) in step 82. The lower limit of the output duty DV is 3% (108,1
11), the upper limit is limited to 97% (109.1
10) In step 112, the output duty DV is updated, but the output duty Dv is.

Step 11 when limited at the lower limit (113, 117) or limited at the upper limit (114, 115)
Since it does not proceed to step 6, the current integration act is ignored and not integrated.

In other words, when a vehicle speed deviation VM-Vo occurs and this state continues for a long time, the integral duty DI gradually increases due to integration, and as a result, the calculated output duty DV also increases and exceeds the limit value (97%). If this state continues, only the integral duty continues to increase while the duty continues to output 97%. The integral value at this time does not increase the output duty, but the increased integral duty only causes an increase in overshoot when the rider descends from the pitch. Therefore, when the output duty DV exceeds the limit value, the integral addition value ΔDI at that time is invalidated (zero). The same applies when the output duty is dropped.

Referring again to FIG. 9a. In step 53, when the output duty DV calculated in r constant speed control duty calculation J (52) is set, the solenoid SLI of the negative pressure control valve IO is duty-controlled at a predetermined period (every 50 s+sec).

Next, when the integral duty DI becomes 25% (5
7) Turn on the motor M that drives the vacuum pump vP (5B), and if the vehicle speed deviation vM-Vo becomes less than 1.0 km/h while the vacuum pump VP is on (5B).
5) Turn off the motor M that drives the vacuum pump VP (5G).The vacuum pump VP may also be turned off when the integral duty DI falls below a predetermined value. When the vehicle speed deviation VM-VO occurs, the opening degree of the throttle valve 5 increases in an attempt to increase the output duty, but the negative pressure in the intake manifold is low and the pressure in the negative pressure chamber in the negative pressure actuator 20 is , decreases, so even if the output duty is increased, the force generated by the negative pressure actuator 20 will not increase, and the throttle valve 20 will not be able to open beyond a certain opening degree.To prevent this, an external negative pressure source ( Use a vacuum pump (vp) in combination.

In step 59, immediately after the vacuum pump vP is driven from off to on, the integral duty DI is set to a predetermined value (
10%) (60). As a result, the negative pressure caused by the negative pressure actuator 20 decreases, and the output duty DV
Vacuum pump vP is turned on from a state in which the pressure is high, and the sudden increase in negative pressure increases the throttle opening to prevent the vehicle from accelerating excessively.

See Figure 9b. When the integral duty DI is 30% or more, (G2) overdrive is prohibited and register T is
Set sdc to 1 (63), that is, when driving, the vehicle speed decreases and even if the output duty DV increases, if the driving force is insufficient, the vehicle speed may gradually decrease, so overdrive is prohibited. By doing so, it increases the drive and power and improves pitching performance. In addition, after prohibiting -carrier overdrive, the vehicle speed deviation VM-VO is 2.0 kg.
If it becomes less than g/h (64), overdrive prohibition is canceled and Tsdc is set to O (65). Note that overdrive prohibition may be canceled when integral duty DI becomes less than a predetermined value. .

Immediately after overdrive is changed from permission to prohibition in step 66, the integral duty DI is reduced by a predetermined value (15%) (67).As a result, when the driving force increases immediately after overdrive is prohibited; When the output duty is increased by the duty DI, the driving force suddenly increases and acceleration is prevented.

In step 69, the phase within the duty control period is checked using register Ra. and register R8
The content of is (69) from O to output duty DV.
Set control solenoid SL1 to ON70
), from the output duty DV to DVmax (duty control period) (72), the control solenoid SL1 is set to OFF (71), and in step 72,
When Ra exceeds DVmax, that is, each time one cycle of duty control ends, the contents of register RB are cleared 73) and time measurement for the next cycle is started.

Timing is performed by a timer interrupt (S17) in FIG.

Therefore, when the control solenoid SLI is controlled on/off according to the calculated output duty DV, the negative pressure control valve 10 alternately opens the negative pressure chamber of the negative pressure actuator 20 to the atmosphere such as the negative pressure system. Squeeze. As a result, the pressure in the negative pressure chamber inside the negative pressure actuator is reduced to duty DV.
The opening degree of the throttle valve 5 is determined accordingly.

Next, referring to FIG. 11, the processing operations of the speed change controller 31 will be explained. When the speed change controller 31 is powered on, it executes initialization and initial setting (120 and 121). Then, it reads the input (122), then checks whether the ITsdc signal from the microcomputer CPU is 1 (shift down designation) (123), and performs the processing corresponding to Tsdc, but the contents are This will be explained later.

After this processing step, the shift lever position 21
22), the shift lever switching is detected, the N neutral position is detected, etc. (12)), and the N
If it is in the position, it returns to reading (122), and the shift lever moves from N to DC drive).

2 or 1, in determining the shift reference data (128), the shift reference data to be referred to for upshifting or downshifting the speed gear (maintaining each speed gear, shifting up or down) , determines the maximum or minimum vehicle speed for the throttle opening (upshift when the vehicle speed exceeds the maximum, downshift when the vehicle speed is below the minimum). Hereinafter, 1 → 2 speed change (shift up) control (129), 2 → 1 speed change (shift down) control (130), 2 → 3 speed change control (132)
, 3→2 speed change control (133), 3→4 speed change control (
135), 4→3 shift control (136) and lock-up control (137) are performed, and reading (122) to lock-up control (137) are repeated. In these shift controls, the shift assigned to the current speed stage is The maximum and minimum vehicle speed values assigned to the current throttle opening in the reference data are compared with the current vehicle speed, and if the current vehicle speed is greater than or equal to the maximum value, it is determined that an upshift is required.

If the current vehicle speed is below the minimum value, it is determined that a downshift is required. If it is determined that an upshift or downshift is necessary, the lockup is released and then the upshift or downshift is executed. When it is not determined that a shift up is necessary, and neither is it determined that a downshift is necessary, the speed stage is not changed and the process proceeds to the first step.

In lock-up control (137), the current vehicle speed is assigned to the current throttle opening of the vehicle speed maximum value (corresponding to throttle opening) and minimum value (corresponding to throttle opening) assigned to the currently set speed stage. The vehicle speed is compared with the current vehicle speed, and if the 11t vehicle speed is higher than the maximum value, the lock-up is performed, and if the vehicle speed is lower than the minimum value, the lock-up is released.

The shift control and lock-up control described above are disclosed in detail in the aforementioned Japanese Patent Application Laid-Open No. 56-39354, so a detailed explanation thereof will be omitted here.

Now, the control operation of the speed change controller 31 in response to the above-mentioned microcomputer CPU downshift instruction (Tsdc=1) will be explained.

The speed change controller 31 reads (122) the signal level of the signal Tsdc from the microcomputer CPU, checks whether it is 1 (shift down instruction) (123), and checks if it is 1 (123). If there,
Checks whether there is a flag (Fsdnwl) indicating that a downshift has been performed in response to a shift/down command (124), and if there is no flag (Fsdnwl), it is found that there is no flag (Fsdnwl) indicating that a downshift has been instructed, but the downshift has not yet been performed. ), release the lock-up and set the speed gear of the transmission mechanism 22-23 to a speed gear one step lower than the one currently being set. - Write (126), then step 131.134 since Fsdn is 1
So, since the content of register F sdn is 1, 2 → 3
Since the shift control (132) and the 3→4 shift control (135) are skipped, these upshifts are not executed, but the downshifts are executed when the conditions are met.

When downshifting and inhibiting upshifting in this way, the microcomputer CPU outputs the signal Ts.
When dc is set to 0 (shift down signal resolution l1l), the shift controller 31 reads this (122), passes through step 23, and clears the contents of register Fsdn in step 13B. As a result, 2→3 shift control (13
2) and 3→4 shift control (135) are executed, and if one condition is met, an upshift is performed.

In addition, in the above-mentioned embodiment, steps (31, 31,
As shown in G4, 65, when overdrive is prohibited (downshift is instructed), if the vehicle speed deviation becomes 2.0 or less than 11176, the prohibition is canceled (downshift instruction is canceled). However, instead of this, the prohibition of overdrive may be canceled when the integral value U) T becomes less than a low value such as 5%. When doing this, the contents of step G4 are rDr<
You can change it to 5%.

〔Effect of the invention〕

As described above, according to the vehicle speed control device of the present invention, the deviation (ΔD
I) When = target speed (RM) - traveling speed (no) is positive, when the integrated value (DI) of the deviation (ΔDI) is greater than or equal to a predetermined value (30%), a downshift is instructed, and the deviation (mouth sno> or integral value (DI) is predetermined fiff(2
, okm/h or 5%), the downshift instruction is canceled. That is, it is possible to quickly detect that the vehicle has entered the climbing state and instruct a downshift, thereby further reducing running at low torque and improving the vehicle's climbing ability.

Furthermore, the output duty is large when a downshift instruction is issued, and the vehicle may accelerate excessively when the driving force increases immediately after the downshift instruction is canceled.

In the present invention, the shift instructing unit (CIIU) subtracts the integrated value (DI) by a predetermined amount (15%) when instructing to downshift. This prevents excessive acceleration of the vehicle.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an electric control circuit of a constant speed traveling device according to a ninth embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing the negative pressure actuator 20 included in the device shown in FIG. FIG. 3 is a flowchart showing the general operation of the microcomputer CPU shown in FIG. Figure 4, Figure 5, Figure G, Figure 7, Figure 8, Figure 98,
FIGS. 9b, 10a, 10a, 10a and 10c are flowcharts showing the subroutine and interrupt processing shown in FIG. 3. FIG. 11 is a flowchart showing the control operation of the microcomputer CPU of the speed change controller 31 shown in FIG. Figures 12a, 12b and 12e are. It is a graph showing the relationship between vehicle speed deviation VM-V and integral addition value ΔDI. 1, Ia, lb: Housing 2: Diaphragm 3:
Compression coil spring 4: Protrusion 5: Throttle valve G: Intake manifold 7: Negative pressure intake 8, 9: Atmospheric intake 10: Negative pressure control valve Eye: Negative pressure release valve 12.14: Movable piece
13.15, 17: Tension coil spring 16: Accelerator pedal 18: Check valve 20; Negative pressure actuator (4th slot slot or Seishi 21: Torque converter 22 Niopatribe mechanism 23: Gear transmission mechanism 24: Output shaft 25: Shift lever position sensor 26.27: Switching solenoid valve 28: Lock anop solenoid valve 29: Rotating shaft 3o speed detection circuit
31: Speed change controller (21-31: Automatic speed change effort LSW: Reed switch Mag: Rotating permanent magnet L
SW, Mag: Preparation detection team CPU: Microcomputer [111 Leg means, gear shift indicator hand (support) LP Nistop lamp [3SW Ni Brake switch CSW: Clutch switch SSW:
Set switch R5W: Resume switch FSl,
FS2: Fuse BT: Battery VRG
: Voltage stabilization circuit IFC: Interface circuit SDI
, Sn2: Solenoid driver SLJ, SL2: Solenoid P: Shinya MD: Motor driver
M: Motor vP: Vacuum bomb Voice 3 figure Figure 4 Door figure 5 *9a figure voice 9b figure rjAIOC figure yfiI12a figure voice 12b figure

Claims (1)

[Claims] Throttle drive means coupled to the throttle valve of the vehicle; Vehicle speed detection means that generates an electric signal according to the speed of the vehicle; Accumulates the deviation between the target speed and the traveling speed and calculates the integrated value. Correspondingly, speed control means biases the throttle drive means in a direction in which the traveling speed matches the target speed; when deviation = target speed - traveling speed is positive, the integrated value of the deviation is greater than or equal to a predetermined value; a gear change instructing means for instructing a downshift at times to update the integrated value to one reduced by a predetermined amount, and canceling the downshift instruction when the deviation or integrated value becomes less than a predetermined value; and the shifting down. A constant speed cruise control device, comprising: automatic transmission means for shifting the speed gear of a transmission to a lower gear in response to an instruction, and suspending shifting from the lower gear to a higher gear while the instruction is received.