ultra sonic following robot ,ultrasonic module noise problem.

Hi, all

I am following the film Make Your Suitcase Haul Itself Around with Robot Luggage! - YouTube with a following suitcase .

My ultrasonic module is a cheap HC-SR04 .
HC-SR04 is pretty fine when in the normal function. As the film ,I also cut the Transmitter and remain the receiver,it is also stable(keep receive 0) when the HC-SR04 is the only module connected to arduino.

Here comes the problem:
Ultrasonic without transmitter bursts a lot of noise when combine the motor module with PWM active in my code.But the normal ultrasonic doesn't have this problem. should I connect some capacitors between power supply and gnd or where?and Why PWM influence ultrasonic without transmitter?

#include <Ultrasonic.h>
#define ECHO_PIN     13
#define TRIGGER_PIN  12
#define InA_L        8   
#define InB_L        9   
#define InA_R        10  
#define InB_R        11  
#define PWM_L        5   
#define PWM_R        6 
int PWM_val_L = 100;                             // (25% = 64; 50% = 127; 75% = 191; 100% = 255)
int PWM_val_R = 100;
Ultrasonic ultrasonic(TRIGGER_PIN, ECHO_PIN);
void setup() {
  Serial.begin(9600);
  digitalWrite(ECHO_PIN,HIGH); 
   pinMode(InA_L,OUTPUT);
   pinMode(InB_L,OUTPUT);
   pinMode(PWM_L,OUTPUT);
  
   pinMode(InA_R,OUTPUT);
   pinMode(InB_R,OUTPUT);
   pinMode(PWM_R,OUTPUT);
}
void advance(int d){   
  analogWrite(PWM_L,PWM_val_L);  
  analogWrite(PWM_R,PWM_val_R); 
  digitalWrite(InA_L,LOW);  
  digitalWrite(InB_L,HIGH);
  digitalWrite(InA_R,LOW);   
  digitalWrite(InB_R,HIGH);
  delay(d * 100);
}
void stopRL(int d){   
  digitalWrite(InA_L,HIGH);   
  digitalWrite(InB_L,HIGH);
  digitalWrite(InA_R,HIGH);   
  digitalWrite(InB_R,HIGH);
  delay(d * 100);
} 


void loop() {
  float cmMsec;
  digitalWrite(TRIGGER_PIN, LOW);
  delayMicroseconds(50);
  digitalWrite(TRIGGER_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN, LOW);
  long microsec = pulseIn(ECHO_PIN, HIGH);
  cmMsec = ultrasonic.convert(microsec, Ultrasonic::CM)*2;
  

  Serial.print("MS: ");
  Serial.print(microsec);
  Serial.print(", CM: ");
  Serial.println(cmMsec);
 
  if(cmMsec>7&&cmMsec<400)
    advance(0);
  else
    stopRL(0);

}

The noise data:

MS: 0, CM: 0.00
MS: 0, CM: 0.00
MS: 0, CM: 0.00
MS: 0, CM: 0.00
MS: 0, CM: 0.00
MS: 0, CM: 0.00
MS: 0, CM: 0.00
MS: 0, CM: 0.00
MS: 0, CM: 0.00
MS: 4037, CM: 146.14
MS: 3635, CM: 131.59
MS: 3461, CM: 125.29
MS: 3402, CM: 123.16
MS: 3533, CM: 127.90
MS: 3520, CM: 127.43
MS: 3487, CM: 126.23
MS: 3603, CM: 130.43
MS: 3597, CM: 130.22
MS: 4136, CM: 149.73
MS: 9731, CM: 352.28
MS: 16456, CM: 595.73
MS: 4055, CM: 146.80
MS: 16766, CM: 606.95
MS: 3291, CM: 119.14
MS: 0, CM: 0.00
MS: 3934, CM: 142.42
MS: 0, CM: 0.00
MS: 4472, CM: 161.89
MS: 6442, CM: 233.21
MS: 6500, CM: 235.31
MS: 6112, CM: 221.26
MS: 5894, CM: 213.37
MS: 6562, CM: 237.55
MS: 7639, CM: 276.54
MS: 5863, CM: 212.25
MS: 8968, CM: 324.65
MS: 3559, CM: 128.84
MS: 6258, CM: 226.55
MS: 7925, CM: 286.90
MS: 9609, CM: 347.86
MS: 8832, CM: 319.73
MS: 17999, CM: 651.59
MS: 3510, CM: 127.07
MS: 6762, CM: 244.79
MS: 7425, CM: 268.79
MS: 13139, CM: 475.65
MS: 3761, CM: 136.15
MS: 7375, CM: 266.98
MS: 3420, CM: 123.81
MS: 11735, CM: 424.82
MS: 3312, CM: 119.90
MS: 9440, CM: 341.74
MS: 3642, CM: 131.85
MS: 7726, CM: 279.69
MS: 11423, CM: 413.53
MS: 3991, CM: 144.48
MS: 7248, CM: 262.39
MS: 7922, CM: 286.79
MS: 7986, CM: 289.10
MS: 3591, CM: 130.00
MS: 7877, CM: 285.16
MS: 5512, CM: 199.54
MS: 6601, CM: 238.96
MS: 8290, CM: 300.11
MS: 6496, CM: 235.16
MS: 3532, CM: 127.86
MS: 12295, CM: 445.10
MS: 2853, CM: 103.28
MS: 11141, CM: 403.32
MS: 3150, CM: 114.03
MS: 8850, CM: 320.38
MS: 8074, CM: 292.29
MS: 4684, CM: 169.57
MS: 3334, CM: 120.70
MS: 0, CM: 0.00
MS: 3583, CM: 129.71
MS: 0, CM: 0.00
MS: 4527, CM: 163.88
MS: 4018, CM: 145.46
MS: 47104, CM: 1705.23
MS: 3578, CM: 129.53
MS: 33960, CM: 1229.40
MS: 3150, CM: 114.03
MS: 46516, CM: 1683.94
MS: 3148, CM: 113.96
MS: 0, CM: 0.00
MS: 4810, CM: 174.13
MS: 21848, CM: 790.93
MS: 3197, CM: 115.74
MS: 3703, CM: 134.05
MS: 21801, CM: 789.23
MS: 3274, CM: 118.52
MS: 24106, CM: 872.67
MS: 4268, CM: 154.51
MS: 0, CM: 0.00
MS: 4430, CM: 160.37
MS: 0, CM: 0.00
MS: 3848, CM: 139.30
MS: 0, CM: 0.00
MS: 4483, CM: 162.29
MS: 17799, CM: 644.35
MS: 3196, CM: 115.70
MS: 35977, CM: 1302.41
MS: 3631, CM: 131.45
MS: 0, CM: 0.00
MS: 4282, CM: 155.01
MS: 12687, CM: 459.29
MS: 3050, CM: 110.41
MS: 30493, CM: 1103.89
MS: 2997, CM: 108.50
MS: 12743, CM: 461.31
MS: 3312, CM: 119.90
MS: 23145, CM: 837.88
MS: 4053, CM: 146.72
MS: 13332, CM: 482.64
MS: 3327, CM: 120.44
MS: 18102, CM: 655.32
MS: 3194, CM: 115.63
MS: 5858, CM: 212.07
MS: 3538, CM: 128.08
MS: 3562, CM: 128.95
MS: 3240, CM: 117.29
MS: 8513, CM: 308.18
MS: 7585, CM: 274.59
MS: 8254, CM: 298.81
MS: 8908, CM: 322.48
MS: 7554, CM: 273.46
MS: 7786, CM: 281.86
MS: 13925, CM: 504.10
MS: 3480, CM: 125.98
MS: 7166, CM: 259.42
MS: 9837, CM: 356.11
MS: 3437, CM: 124.42
MS: 8712, CM: 315.39
MS: 12406, CM: 449.11
MS: 3406, CM: 123.30
MS: 9724, CM: 352.02
MS: 7739, CM: 280.16
MS: 6969, CM: 252.29
MS: 10070, CM: 364.55
MS: 7266, CM: 263.04
MS: 8356, CM: 302.50
MS: 9021, CM: 326.57
MS: 6651, CM: 240.77
MS: 6308, CM: 228.36
MS: 9568, CM: 346.37
MS: 9220, CM: 333.78
MS: 3251, CM: 117.69
MS: 8956, CM: 324.22
MS: 5570, CM: 201.64
MS: 8837, CM: 319.91
MS: 7485, CM: 270.97
MS: 6558, CM: 237.41
MS: 5778, CM: 209.17
MS: 7883, CM: 285.38
MS: 7537, CM: 272.85
MS: 5170, CM: 187.16
MS: 6845, CM: 247.80
MS: 6500, CM: 235.31
MS: 8171, CM: 295.80
MS: 3352, CM: 121.35
MS: 10081, CM: 364.95
MS: 7116, CM: 257.61
MS: 3304, CM: 119.61
MS: 9024, CM: 326.68
MS: 6642, CM: 240.45
MS: 3275, CM: 118.56
MS: 9994, CM: 361.80
MS: 6025, CM: 218.11
MS: 6699, CM: 242.51
MS: 3325, CM: 120.37
MS: 7004, CM: 253.55
MS: 7670, CM: 277.66
MS: 7333, CM: 265.46
MS: 7985, CM: 289.07
MS: 10681, CM: 386.67
MS: 8299, CM: 300.43
MS: 18043, CM: 653.18
MS: 3548, CM: 128.44
MS: 0, CM: 0.00
MS: 3781, CM: 136.88
MS: 0, CM: 0.00
MS: 4063, CM: 147.09
MS: 19237, CM: 696.40
MS: 3206, CM: 116.06
MS: 14188, CM: 513.62
MS: 3197, CM: 115.74
MS: 16038, CM: 580.60
MS: 3572, CM: 129.31
MS: 0, CM: 0.00
MS: 3801, CM: 137.60
MS: 3649, CM: 132.10
MS: 16794, CM: 607.97
MS: 3194, CM: 115.63
MS: 17748, CM: 642.50
MS: 3905, CM: 141.37
MS: 18037, CM: 652.96
MS: 3549, CM: 128.48
MS: 26432, CM: 956.87
MS: 3617, CM: 130.94
MS: 16198, CM: 586.39
MS: 3156, CM: 114.25
MS: 0, CM: 0.00
MS: 4385, CM: 158.74
MS: 0, CM: 0.00
MS: 4063, CM: 147.09
MS: 6703, CM: 242.66
MS: 0, CM: 0.00
MS: 3792, CM: 137.28